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* mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLEJoonsoo Kim2018-04-111-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE", v2. 0. History This patchset is the follow-up of the discussion about the "Introduce ZONE_CMA (v7)" [1]. Please reference it if more information is needed. 1. What does this patch do? This patch changes the management way for the memory of the CMA area in the MM subsystem. Currently the memory of the CMA area is managed by the zone where their pfn is belong to. However, this approach has some problems since MM subsystem doesn't have enough logic to handle the situation that different characteristic memories are in a single zone. To solve this issue, this patch try to manage all the memory of the CMA area by using the MOVABLE zone. In MM subsystem's point of view, characteristic of the memory on the MOVABLE zone and the memory of the CMA area are the same. So, managing the memory of the CMA area by using the MOVABLE zone will not have any problem. 2. Motivation There are some problems with current approach. See following. Although these problem would not be inherent and it could be fixed without this conception change, it requires many hooks addition in various code path and it would be intrusive to core MM and would be really error-prone. Therefore, I try to solve them with this new approach. Anyway, following is the problems of the current implementation. o CMA memory utilization First, following is the freepage calculation logic in MM. - For movable allocation: freepage = total freepage - For unmovable allocation: freepage = total freepage - CMA freepage Freepages on the CMA area is used after the normal freepages in the zone where the memory of the CMA area is belong to are exhausted. At that moment that the number of the normal freepages is zero, so - For movable allocation: freepage = total freepage = CMA freepage - For unmovable allocation: freepage = 0 If unmovable allocation comes at this moment, allocation request would fail to pass the watermark check and reclaim is started. After reclaim, there would exist the normal freepages so freepages on the CMA areas would not be used. FYI, there is another attempt [2] trying to solve this problem in lkml. And, as far as I know, Qualcomm also has out-of-tree solution for this problem. Useless reclaim: There is no logic to distinguish CMA pages in the reclaim path. Hence, CMA page is reclaimed even if the system just needs the page that can be usable for the kernel allocation. Atomic allocation failure: This is also related to the fallback allocation policy for the memory of the CMA area. Consider the situation that the number of the normal freepages is *zero* since the bunch of the movable allocation requests come. Kswapd would not be woken up due to following freepage calculation logic. - For movable allocation: freepage = total freepage = CMA freepage If atomic unmovable allocation request comes at this moment, it would fails due to following logic. - For unmovable allocation: freepage = total freepage - CMA freepage = 0 It was reported by Aneesh [3]. Useless compaction: Usual high-order allocation request is unmovable allocation request and it cannot be served from the memory of the CMA area. In compaction, migration scanner try to migrate the page in the CMA area and make high-order page there. As mentioned above, it cannot be usable for the unmovable allocation request so it's just waste. 3. Current approach and new approach Current approach is that the memory of the CMA area is managed by the zone where their pfn is belong to. However, these memory should be distinguishable since they have a strong limitation. So, they are marked as MIGRATE_CMA in pageblock flag and handled specially. However, as mentioned in section 2, the MM subsystem doesn't have enough logic to deal with this special pageblock so many problems raised. New approach is that the memory of the CMA area is managed by the MOVABLE zone. MM already have enough logic to deal with special zone like as HIGHMEM and MOVABLE zone. So, managing the memory of the CMA area by the MOVABLE zone just naturally work well because constraints for the memory of the CMA area that the memory should always be migratable is the same with the constraint for the MOVABLE zone. There is one side-effect for the usability of the memory of the CMA area. The use of MOVABLE zone is only allowed for a request with GFP_HIGHMEM && GFP_MOVABLE so now the memory of the CMA area is also only allowed for this gfp flag. Before this patchset, a request with GFP_MOVABLE can use them. IMO, It would not be a big issue since most of GFP_MOVABLE request also has GFP_HIGHMEM flag. For example, file cache page and anonymous page. However, file cache page for blockdev file is an exception. Request for it has no GFP_HIGHMEM flag. There is pros and cons on this exception. In my experience, blockdev file cache pages are one of the top reason that causes cma_alloc() to fail temporarily. So, we can get more guarantee of cma_alloc() success by discarding this case. Note that there is no change in admin POV since this patchset is just for internal implementation change in MM subsystem. Just one minor difference for admin is that the memory stat for CMA area will be printed in the MOVABLE zone. That's all. 4. Result Following is the experimental result related to utilization problem. 8 CPUs, 1024 MB, VIRTUAL MACHINE make -j16 <Before> CMA area: 0 MB 512 MB Elapsed-time: 92.4 186.5 pswpin: 82 18647 pswpout: 160 69839 <After> CMA : 0 MB 512 MB Elapsed-time: 93.1 93.4 pswpin: 84 46 pswpout: 183 92 akpm: "kernel test robot" reported a 26% improvement in vm-scalability.throughput: http://lkml.kernel.org/r/20180330012721.GA3845@yexl-desktop [1]: lkml.kernel.org/r/1491880640-9944-1-git-send-email-iamjoonsoo.kim@lge.com [2]: https://lkml.org/lkml/2014/10/15/623 [3]: http://www.spinics.net/lists/linux-mm/msg100562.html Link: http://lkml.kernel.org/r/1512114786-5085-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: disable interrupts while initializing deferred pagesPavel Tatashin2018-04-051-25/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Vlastimil Babka reported about a window issue during which when deferred pages are initialized, and the current version of on-demand initialization is finished, allocations may fail. While this is highly unlikely scenario, since this kind of allocation request must be large, and must come from interrupt handler, we still want to cover it. We solve this by initializing deferred pages with interrupts disabled, and holding node_size_lock spin lock while pages in the node are being initialized. The on-demand deferred page initialization that comes later will use the same lock, and thus synchronize with deferred_init_memmap(). It is unlikely for threads that initialize deferred pages to be interrupted. They run soon after smp_init(), but before modules are initialized, and long before user space programs. This is why there is no adverse effect of having these threads running with interrupts disabled. [pasha.tatashin@oracle.com: v6] Link: http://lkml.kernel.org/r/20180313182355.17669-2-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180309220807.24961-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: pass the vmem_altmap to memmap_init_zoneChristoph Hellwig2018-01-081-1/+1
| | | | | | | Pass the vmem_altmap two levels down instead of needing a lookup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: pass the vmem_altmap to vmemmap_freeChristoph Hellwig2018-01-081-1/+1
| | | | | | | | We can just pass this on instead of having to do a radix tree lookup without proper locking a few levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: pass the vmem_altmap to arch_remove_memory and __remove_pagesChristoph Hellwig2018-01-081-2/+3
| | | | | | | | We can just pass this on instead of having to do a radix tree lookup without proper locking 2 levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: pass the vmem_altmap to vmemmap_populateChristoph Hellwig2018-01-081-1/+2
| | | | | | | | We can just pass this on instead of having to do a radix tree lookup without proper locking a few levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: pass the vmem_altmap to arch_add_memory and __add_pagesChristoph Hellwig2018-01-081-7/+10
| | | | | | | | We can just pass this on instead of having to do a radix tree lookup without proper locking 2 levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memory_hotplug: introduce add_pagesMichal Hocko2017-09-081-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are new users of memory hotplug emerging. Some of them require different subset of arch_add_memory. There are some which only require allocation of struct pages without mapping those pages to the kernel address space. We currently have __add_pages for that purpose. But this is rather lowlevel and not very suitable for the code outside of the memory hotplug. E.g. x86_64 wants to update max_pfn which should be done by the caller. Introduce add_pages() which should care about those details if they are needed. Each architecture should define its implementation and select CONFIG_ARCH_HAS_ADD_PAGES. All others use the currently existing __add_pages. Link: http://lkml.kernel.org/r/20170817000548.32038-7-jglisse@redhat.com Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: display allowed zones in the preferred orderingMichal Hocko2017-09-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to commit f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") we used to allow to change the valid zone types of a memory block if it is adjacent to a different zone type. This fact was reflected in memoryNN/valid_zones by the ordering of printed zones. The first one was default (echo online > memoryNN/state) and the other one could be onlined explicitly by online_{movable,kernel}. This behavior was removed by the said patch and as such the ordering was not all that important. In most cases a kernel zone would be default anyway. The only exception is movable_node handled by "mm, memory_hotplug: support movable_node for hotpluggable nodes". Let's reintroduce this behavior again because later patch will remove the zone overlap restriction and so user will be allowed to online kernel resp. movable block regardless of its placement. Original behavior will then become significant again because it would be non-trivial for users to see what is the default zone to online into. Implementation is really simple. Pull out zone selection out of move_pfn_range into zone_for_pfn_range helper and use it in show_valid_zones to display the zone for default onlining and then both kernel and movable if they are allowed. Default online zone is not duplicated. Link: http://lkml.kernel.org/r/20170714121233.16861-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: <slaoub@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: move movable_node to the hotplug properMichal Hocko2017-07-061-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | movable_node_is_enabled is defined in memblock proper while it is initialized from the memory hotplug proper. This is quite messy and it makes a dependency between the two so move movable_node along with the helper functions to memory_hotplug. To make it more entertaining the kernel parameter is ignored unless CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node information for each memblock otherwise. So let's warn when the option is disabled. Link: http://lkml.kernel.org/r/20170529114141.536-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: remove unused cruft after memory hotplug reworkMichal Hocko2017-07-061-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zone_for_memory doesn't have any user anymore as well as the whole zone shifting infrastructure so drop them all. This shouldn't introduce any functional changes. Link: http://lkml.kernel.org/r/20170515085827.16474-15-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: replace for_device by want_memblock in arch_add_memoryMichal Hocko2017-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_add_memory gets for_device argument which then controls whether we want to create memblocks for created memory sections. Simplify the logic by telling whether we want memblocks directly rather than going through pointless negation. This also makes the api easier to understand because it is clear what we want rather than nothing telling for_device which can mean anything. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-13-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: do not assume ZONE_NORMAL is default kernel zoneMichal Hocko2017-07-061-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Heiko Carstens has noticed that he can generate overlapping zones for ZONE_DMA and ZONE_NORMAL: DMA [mem 0x0000000000000000-0x000000007fffffff] Normal [mem 0x0000000080000000-0x000000017fffffff] $ cat /sys/devices/system/memory/block_size_bytes 10000000 $ cat /sys/devices/system/memory/memory5/valid_zones DMA $ echo 0 > /sys/devices/system/memory/memory5/online $ cat /sys/devices/system/memory/memory5/valid_zones Normal $ echo 1 > /sys/devices/system/memory/memory5/online Normal $ cat /proc/zoneinfo Node 0, zone DMA spanned 524288 <----- present 458752 managed 455078 start_pfn: 0 <----- Node 0, zone Normal spanned 720896 present 589824 managed 571648 start_pfn: 327680 <----- The reason is that we assume that the default zone for kernel onlining is ZONE_NORMAL. This was a simplification introduced by the memory hotplug rework and it is easily fixable by checking the range overlap in the zone order and considering the first matching zone as the default one. If there is no such zone then assume ZONE_NORMAL as we have been doing so far. Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online" Link: http://lkml.kernel.org/r/20170601083746.4924-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: do not associate hotadded memory to zones until onlineMichal Hocko2017-07-061-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current memory hotplug implementation relies on having all the struct pages associate with a zone/node during the physical hotplug phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the vast majority of cases this means that they are added to ZONE_NORMAL. This has been so since 9d99aaa31f59 ("[PATCH] x86_64: Support memory hotadd without sparsemem") and it wasn't a big deal back then because movable onlining didn't exist yet. Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable onlining 511c2aba8f07 ("mm, memory-hotplug: dynamic configure movable memory and portion memory") and then things got more complicated. Rather than reconsidering the zone association which was no longer needed (because the memory hotplug already depended on SPARSEMEM) a convoluted semantic of zone shifting has been developed. Only the currently last memblock or the one adjacent to the zone_movable can be onlined movable. This essentially means that the online type changes as the new memblocks are added. Let's simulate memory hot online manually $ echo 0x100000000 > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory32/valid_zones Normal Movable $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal Movable $ echo online_movable > /sys/devices/system/memory/memory34/state $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Normal This is an awkward semantic because an udev event is sent as soon as the block is onlined and an udev handler might want to online it based on some policy (e.g. association with a node) but it will inherently race with new blocks showing up. This patch changes the physical online phase to not associate pages with any zone at all. All the pages are just marked reserved and wait for the onlining phase to be associated with the zone as per the online request. There are only two requirements - existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap - ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses the latter one is not an inherent requirement and can be changed in the future. It preserves the current behavior and made the code slightly simpler. This is subject to change in future. This means that the same physical online steps as above will lead to the following state: Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Implementation: The current move_pfn_range is reimplemented to check the above requirements (allow_online_pfn_range) and then updates the respective zone (move_pfn_range_to_zone), the pgdat and links all the pages in the pfn range with the zone/node. __add_pages is updated to not require the zone and only initializes sections in the range. This allowed to simplify the arch_add_memory code (s390 could get rid of quite some of code). devm_memremap_pages is the only user of arch_add_memory which relies on the zone association because it only hooks into the memory hotplug only half way. It uses it to associate the new memory with ZONE_DEVICE but doesn't allow it to be {on,off}lined via sysfs. This means that this particular code path has to call move_pfn_range_to_zone explicitly. The original zone shifting code is kept in place and will be removed in the follow up patch for an easier review. Please note that this patch also changes the original behavior when offlining a memory block adjacent to another zone (Normal vs. Movable) used to allow to change its movable type. This will be handled later. [richard.weiyang@gmail.com: simplify zone_intersects()] Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com [richard.weiyang@gmail.com: remove duplicate call for set_page_links] Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com [akpm@linux-foundation.org: remove unused local `i'] Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: consider zone which is not fully populated to have holesMichal Hocko2017-07-061-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __pageblock_pfn_to_page has two users currently, set_zone_contiguous which checks whether the given zone contains holes and pageblock_pfn_to_page which then carefully returns a first valid page from the given pfn range for the given zone. This doesn't handle zones which are not fully populated though. Memory pageblocks can be offlined or might not have been onlined yet. In such a case the zone should be considered to have holes otherwise pfn walkers can touch and play with offline pages. Current callers of pageblock_pfn_to_page in compaction seem to work properly right now because they only isolate PageBuddy (isolate_freepages_block) or PageLRU resp. __PageMovable (isolate_migratepages_block) which will be always false for these pages. It would be safer to skip these pages altogether, though. In order to do this patch adds a new memory section state (SECTION_IS_ONLINE) which is set in memory_present (during boot time) or in online_pages_range during the memory hotplug. Similarly offline_mem_sections clears the bit and it is called when the memory range is offlined. pfn_to_online_page helper is then added which check the mem section and only returns a page if it is onlined already. Use the new helper in __pageblock_pfn_to_page and skip the whole page block in such a case. [mhocko@suse.com: check valid section number in pfn_to_online_page (Vlastimil), mark sections online after all struct pages are initialized in online_pages_range (Vlastimil)] Link: http://lkml.kernel.org/r/20170518164210.GD18333@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170515085827.16474-8-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: get rid of is_zone_device_sectionMichal Hocko2017-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Device memory hotplug hooks into regular memory hotplug only half way. It needs memory sections to track struct pages but there is no need/desire to associate those sections with memory blocks and export them to the userspace via sysfs because they cannot be onlined anyway. This is currently expressed by for_device argument to arch_add_memory which then makes sure to associate the given memory range with ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to distinguish special memory hotplug from the regular one. While this works now, later patches in this series want to move __add_zone outside of arch_add_memory path so we have to come up with something else. Add want_memblock down the __add_pages path and use it to control whether the section->memblock association should be done. arch_add_memory then just trivially want memblock for everything but for_device hotplug. remove_memory_section doesn't need is_zone_device_section either. We can simply skip all the memblock specific cleanup if there is no memblock for the given section. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* base/memory, hotplug: fix a kernel oops in show_valid_zones()Toshi Kani2017-02-031-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reading a sysfs "memoryN/valid_zones" file leads to the following oops when the first page of a range is not backed by struct page. show_valid_zones() assumes that 'start_pfn' is always valid for page_zone(). BUG: unable to handle kernel paging request at ffffea017a000000 IP: show_valid_zones+0x6f/0x160 This issue may happen on x86-64 systems with 64GiB or more memory since their memory block size is bumped up to 2GiB. [1] An example of such systems is desribed below. 0x3240000000 is only aligned by 1GiB and this memory block starts from 0x3200000000, which is not backed by struct page. BIOS-e820: [mem 0x0000003240000000-0x000000603fffffff] usable Since test_pages_in_a_zone() already checks holes, fix this issue by extending this function to return 'valid_start' and 'valid_end' for a given range. show_valid_zones() then proceeds with the valid range. [1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems")' Link: http://lkml.kernel.org/r/20170127222149.30893-3-toshi.kani@hpe.com Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> [4.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory_hotplug: make zone_can_shift() return a boolean valueYasuaki Ishimatsu2017-01-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | online_{kernel|movable} is used to change the memory zone to ZONE_{NORMAL|MOVABLE} and online the memory. To check that memory zone can be changed, zone_can_shift() is used. Currently the function returns minus integer value, plus integer value and 0. When the function returns minus or plus integer value, it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}. But when the function returns 0, there are two meanings. One of the meanings is that the memory zone does not need to be changed. For example, when memory is in ZONE_NORMAL and onlined by online_kernel the memory zone does not need to be changed. Another meaning is that the memory zone cannot be changed. When memory is in ZONE_NORMAL and onlined by online_movable, the memory zone may not be changed to ZONE_MOVALBE due to memory online limitation(see Documentation/memory-hotplug.txt). In this case, memory must not be onlined. The patch changes the return type of zone_can_shift() so that memory online operation fails when memory zone cannot be changed as follows: Before applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 8388608 managed 8388608 online_movable operation succeeded. But memory is onlined as ZONE_NORMAL, not ZONE_MOVABLE. After applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state bash: echo: write error: Invalid argument # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 online_movable operation failed because of failure of changing the memory zone from ZONE_NORMAL to ZONE_MOVABLE Fixes: df429ac03936 ("memory-hotplug: more general validation of zone during online") Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.com Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: more general validation of zone during onlineReza Arbab2016-07-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When memory is onlined, we are only able to rezone from ZONE_MOVABLE to ZONE_KERNEL, or from (ZONE_MOVABLE - 1) to ZONE_MOVABLE. To be more flexible, use the following criteria instead; to online memory from zone X into zone Y, * Any zones between X and Y must be unused. * If X is lower than Y, the onlined memory must lie at the end of X. * If X is higher than Y, the onlined memory must lie at the start of X. Add zone_can_shift() to make this determination. Link: http://lkml.kernel.org/r/1462816419-4479-3-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Reviewd-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix section mismatch warningLinus Torvalds2016-05-271-1/+1
| | | | | | | | | | | | | The register_page_bootmem_info_node() function needs to be marked __init in order to avoid a new warning introduced by commit f65e91df25aa ("mm: use early_pfn_to_nid in register_page_bootmem_info_node"). Otherwise you'll get a warning about how a non-init function calls early_pfn_to_nid (which is __meminit) Cc: Yang Shi <yang.shi@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: is_mem_section_removable() can return boolYaowei Bai2016-05-191-3/+3
| | | | | | | | | | Make is_mem_section_removable() return bool to improve readability due to this particular function only using either one or zero as its return value. Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguousJoonsoo Kim2016-03-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a performance drop report due to hugepage allocation and in there half of cpu time are spent on pageblock_pfn_to_page() in compaction [1]. In that workload, compaction is triggered to make hugepage but most of pageblocks are un-available for compaction due to pageblock type and skip bit so compaction usually fails. Most costly operations in this case is to find valid pageblock while scanning whole zone range. To check if pageblock is valid to compact, valid pfn within pageblock is required and we can obtain it by calling pageblock_pfn_to_page(). This function checks whether pageblock is in a single zone and return valid pfn if possible. Problem is that we need to check it every time before scanning pageblock even if we re-visit it and this turns out to be very expensive in this workload. Although we have no way to skip this pageblock check in the system where hole exists at arbitrary position, we can use cached value for zone continuity and just do pfn_to_page() in the system where hole doesn't exist. This optimization considerably speeds up in above workload. Before vs After Max: 1096 MB/s vs 1325 MB/s Min: 635 MB/s 1015 MB/s Avg: 899 MB/s 1194 MB/s Avg is improved by roughly 30% [2]. [1]: http://www.spinics.net/lists/linux-mm/msg97378.html [2]: https://lkml.org/lkml/2015/12/9/23 [akpm@linux-foundation.org: don't forget to restore zone->contiguous on error path, per Vlastimil] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Aaron Lu <aaron.lu@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: add automatic onlining policy for the newly added memoryVitaly Kuznetsov2016-03-151-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all newly added memory blocks remain in 'offline' state unless someone onlines them, some linux distributions carry special udev rules like: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" to make this happen automatically. This is not a great solution for virtual machines where memory hotplug is being used to address high memory pressure situations as such onlining is slow and a userspace process doing this (udev) has a chance of being killed by the OOM killer as it will probably require to allocate some memory. Introduce default policy for the newly added memory blocks in /sys/devices/system/memory/auto_online_blocks file with two possible values: "offline" which preserves the current behavior and "online" which causes all newly added memory blocks to go online as soon as they're added. The default is "offline". Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86, mm: introduce vmem_altmap to augment vmemmap_populate()Dan Williams2016-01-151-1/+2
| | | | | | | | | | | | | | | | | | | | In support of providing struct page for large persistent memory capacities, use struct vmem_altmap to change the default policy for allocating memory for the memmap array. The default vmemmap_populate() allocates page table storage area from the page allocator. Given persistent memory capacities relative to DRAM it may not be feasible to store the memmap in 'System Memory'. Instead vmem_altmap represents pre-allocated "device pages" to satisfy vmemmap_alloc_block_buf() requests. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: kbuild test robot <lkp@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memory hotplug with an existing resourceDavid Vrabel2015-10-231-0/+2
| | | | | | | | | | | | | Add add_memory_resource() to add memory using an existing "System RAM" resource. This is useful if the memory region is being located by finding a free resource slot with allocate_resource(). Xen guests will make use of this in their balloon driver to hotplug arbitrary amounts of memory in response to toolstack requests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
* mm: ZONE_DEVICE for "device memory"Dan Williams2015-08-271-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | While pmem is usable as a block device or via DAX mappings to userspace there are several usage scenarios that can not target pmem due to its lack of struct page coverage. In preparation for "hot plugging" pmem into the vmemmap add ZONE_DEVICE as a new zone to tag these pages separately from the ones that are subject to standard page allocations. Importantly "device memory" can be removed at will by userspace unbinding the driver of the device. Having a separate zone prevents allocation and otherwise marks these pages that are distinct from typical uniform memory. Device memory has different lifetime and performance characteristics than RAM. However, since we have run out of ZONES_SHIFT bits this functionality currently depends on sacrificing ZONE_DMA. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Jerome Glisse <j.glisse@gmail.com> [hch: various simplifications in the arch interface] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm, hotplug: fix concurrent memory hot-add deadlockDavid Rientjes2015-04-141-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a deadlock when concurrently hot-adding memory through the probe interface and switching a memory block from offline to online. When hot-adding memory via the probe interface, add_memory() first takes mem_hotplug_begin() and then device_lock() is later taken when registering the newly initialized memory block. This creates a lock dependency of (1) mem_hotplug.lock (2) dev->mutex. When switching a memory block from offline to online, dev->mutex is first grabbed in device_online() when the write(2) transitions an existing memory block from offline to online, and then online_pages() will take mem_hotplug_begin(). This creates a lock inversion between mem_hotplug.lock and dev->mutex. Vitaly reports that this deadlock can happen when kworker handling a probe event races with systemd-udevd switching a memory block's state. This patch requires the state transition to take mem_hotplug_begin() before dev->mutex. Hot-adding memory via the probe interface creates a memory block while holding mem_hotplug_begin(), there is no way to take dev->mutex first in this case. online_pages() and offline_pages() are only called when transitioning memory block state. We now require that mem_hotplug_begin() is taken before calling them -- this requires exporting the mem_hotplug_begin() and mem_hotplug_done() to generic code. In all hot-add and hot-remove cases, mem_hotplug_begin() is done prior to device_online(). This is all that is needed to avoid the deadlock. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: add sysfs valid_zones attributeZhang Zhen2014-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently memory-hotplug has two limits: 1. If the memory block is in ZONE_NORMAL, you can change it to ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE. 2. If the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL. With this patch, we can easy to know a memory block can be onlined to which zone, and don't need to know the above two limits. Updated the related Documentation. [akpm@linux-foundation.org: use conventional comment layout] [akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n] [akpm@linux-foundation.org: remove unused local zone_prev] Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: add zone_for_memory() for selecting zone for new memoryWang Nan2014-08-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This series of patches fixes a problem when adding memory in bad manner. For example: for a x86_64 machine booted with "mem=400M" and with 2GiB memory installed, following commands cause problem: # echo 0x40000000 > /sys/devices/system/memory/probe [ 28.613895] init_memory_mapping: [mem 0x40000000-0x47ffffff] # echo 0x48000000 > /sys/devices/system/memory/probe [ 28.693675] init_memory_mapping: [mem 0x48000000-0x4fffffff] # echo online_movable > /sys/devices/system/memory/memory9/state # echo 0x50000000 > /sys/devices/system/memory/probe [ 29.084090] init_memory_mapping: [mem 0x50000000-0x57ffffff] # echo 0x58000000 > /sys/devices/system/memory/probe [ 29.151880] init_memory_mapping: [mem 0x58000000-0x5fffffff] # echo online_movable > /sys/devices/system/memory/memory11/state # echo online> /sys/devices/system/memory/memory8/state # echo online> /sys/devices/system/memory/memory10/state # echo offline> /sys/devices/system/memory/memory9/state [ 30.558819] Offlined Pages 32768 # free total used free shared buffers cached Mem: 780588 18014398509432020 830552 0 0 51180 -/+ buffers/cache: 18014398509380840 881732 Swap: 0 0 0 This is because the above commands probe higher memory after online a section with online_movable, which causes ZONE_HIGHMEM (or ZONE_NORMAL for systems without ZONE_HIGHMEM) overlaps ZONE_MOVABLE. After the second online_movable, the problem can be observed from zoneinfo: # cat /proc/zoneinfo ... Node 0, zone Movable pages free 65491 min 250 low 312 high 375 scanned 0 spanned 18446744073709518848 present 65536 managed 65536 ... This series of patches solve the problem by checking ZONE_MOVABLE when choosing zone for new memory. If new memory is inside or higher than ZONE_MOVABLE, makes it go there instead. After applying this series of patches, following are free and zoneinfo result (after offlining memory9): bash-4.2# free total used free shared buffers cached Mem: 780956 80112 700844 0 0 51180 -/+ buffers/cache: 28932 752024 Swap: 0 0 0 bash-4.2# cat /proc/zoneinfo Node 0, zone DMA pages free 3389 min 14 low 17 high 21 scanned 0 spanned 4095 present 3998 managed 3977 nr_free_pages 3389 ... start_pfn: 1 inactive_ratio: 1 Node 0, zone DMA32 pages free 73724 min 341 low 426 high 511 scanned 0 spanned 98304 present 98304 managed 92958 nr_free_pages 73724 ... start_pfn: 4096 inactive_ratio: 1 Node 0, zone Normal pages free 32630 min 120 low 150 high 180 scanned 0 spanned 32768 present 32768 managed 32768 nr_free_pages 32630 ... start_pfn: 262144 inactive_ratio: 1 Node 0, zone Movable pages free 65476 min 241 low 301 high 361 scanned 0 spanned 98304 present 65536 managed 65536 nr_free_pages 65476 ... start_pfn: 294912 inactive_ratio: 1 This patch (of 7): Introduce zone_for_memory() in arch independent code for arch_add_memory() use. Many arch_add_memory() function simply selects ZONE_HIGHMEM or ZONE_NORMAL and add new memory into it. However, with the existance of ZONE_MOVABLE, the selection method should be carefully considered: if new, higher memory is added after ZONE_MOVABLE is setup, the default zone and ZONE_MOVABLE may overlap each other. should_add_memory_movable() checks the status of ZONE_MOVABLE. If it has already contain memory, compare the address of new memory and movable memory. If new memory is higher than movable, it should be added into ZONE_MOVABLE instead of default zone. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Mel Gorman" <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: introduce MMOP_OFFLINE to replace the hard coding -1Tang Chen2014-08-061-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In store_mem_state(), we have: ... 334 else if (!strncmp(buf, "offline", min_t(int, count, 7))) 335 online_type = -1; ... 355 case -1: 356 ret = device_offline(&mem->dev); 357 break; ... Here, "offline" is hard coded as -1. This patch does the following renaming: ONLINE_KEEP -> MMOP_ONLINE_KEEP ONLINE_KERNEL -> MMOP_ONLINE_KERNEL ONLINE_MOVABLE -> MMOP_ONLINE_MOVABLE and introduces MMOP_OFFLINE = -1 to avoid hard coding. Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Hu Tao <hutao@cn.fujitsu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: implement get/put_online_memsVladimir Davydov2014-06-041-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmem_cache_{create,destroy,shrink} need to get a stable value of cpu/node online mask, because they init/destroy/access per-cpu/node kmem_cache parts, which can be allocated or destroyed on cpu/mem hotplug. To protect against cpu hotplug, these functions use {get,put}_online_cpus. However, they do nothing to synchronize with memory hotplug - taking the slab_mutex does not eliminate the possibility of race as described in patch 2. What we need there is something like get_online_cpus, but for memory. We already have lock_memory_hotplug, which serves for the purpose, but it's a bit of a hammer right now, because it's backed by a mutex. As a result, it imposes some limitations to locking order, which are not desirable, and can't be used just like get_online_cpus. That's why in patch 1 I substitute it with get/put_online_mems, which work exactly like get/put_online_cpus except they block not cpu, but memory hotplug. [ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by myself, because it used an rw semaphore for get/put_online_mems, making them dead lock prune. ] This patch (of 2): {un}lock_memory_hotplug, which is used to synchronize against memory hotplug, is currently backed by a mutex, which makes it a bit of a hammer - threads that only want to get a stable value of online nodes mask won't be able to proceed concurrently. Also, it imposes some strong locking ordering rules on it, which narrows down the set of its usage scenarios. This patch introduces get/put_online_mems, which are the same as get/put_online_cpus, but for memory hotplug, i.e. executing a code inside a get/put_online_mems section will guarantee a stable value of online nodes, present pages, etc. lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparsemem: use PAGES_PER_SECTION to remove redundant nr_pages parameterZhang Yanfei2013-11-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | For below functions, - sparse_add_one_section() - kmalloc_section_memmap() - __kmalloc_section_memmap() - __kfree_section_memmap() they are always invoked to operate on one memory section, so it is redundant to always pass a nr_pages parameter, which is the page numbers in one section. So we can directly use predefined macro PAGES_PER_SECTION instead of passing the parameter. Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpu/mem hotplug: add try_online_node() for cpu_up()Toshi Kani2013-11-131-1/+7
| | | | | | | | | | | | | | | | | | | | | | cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call mem_online_node() to put its node online if offlined and then call build_all_zonelists() to initialize the zone list. These steps are specific to memory hotplug, and should be managed in mm/memory_hotplug.c. lock_memory_hotplug() should also be held for the whole steps. For this reason, this patch replaces mem_online_node() with try_online_node(), which performs the whole steps with lock_memory_hotplug() held. try_online_node() is named after try_offline_node() as they have similar purpose. There is no functional change in this patch. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Memory hotplug: Move alternative function definitions to headerRafael J. Wysocki2013-06-011-0/+9
| | | | | | | | Move the definitions of offline_pages() and remove_memory() for CONFIG_MEMORY_HOTREMOVE to memory_hotplug.h, where they belong, and make them static inline. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Memory hotplug / ACPI: Simplify memory removalRafael J. Wysocki2013-06-011-1/+1
| | | | | | | | | | | | | | | Now that the memory offlining should be taken care of by the companion device offlining code in acpi_scan_hot_remove(), the ACPI memory hotplug driver doesn't need to offline it in remove_memory() any more. Moreover, since the return value of remove_memory() is not used, it's better to make it be a void function and trigger a BUG() if the memory scheduled for removal is not offline. Change the code in accordance with the above observations. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com>
* Driver core / MM: Drop offline_memory_block()Rafael J. Wysocki2013-06-011-1/+0
| | | | | | | | | | Since offline_memory_block(mem) is functionally equivalent to device_offline(&mem->dev), make the only caller of the former use the latter instead and drop offline_memory_block() entirely. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Toshi Kani <toshi.kani@hp.com>
* ACPI / memhotplug: Bind removable memory blocks to ACPI device nodesRafael J. Wysocki2013-05-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | During ACPI memory hotplug configuration bind memory blocks residing in modules removable through the standard ACPI mechanism to struct acpi_device objects associated with ACPI namespace objects representing those modules. Accordingly, unbind those memory blocks from the struct acpi_device objects when the memory modules in question are being removed. When "offline" operation for devices representing memory blocks is introduced, this will allow the ACPI core's device hot-remove code to use it to carry out remove_memory() for those memory blocks and check the results of that before it actually removes the modules holding them from the system. Since walk_memory_range() is used for accessing all memory blocks corresponding to a given ACPI namespace object, it is exported from memory_hotplug.c so that the code in acpi_memhotplug.c can use it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com>
* mm, hotplug: avoid compiling memory hotremove functions when disabledDavid Rientjes2013-04-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | __remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE. PowerPC pseries will return -EOPNOTSUPP if unsupported. Adding an #ifdef causes several other functions it depends on to also become unnecessary, which saves in .text when disabled (it's disabled in most defconfigs besides powerpc, including x86). remove_memory_block() becomes static since it is not referenced outside of drivers/base/memory.c. Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled and disabled. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: export the function try_offline_node()Wen Congyang2013-02-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_offline_node() will be needed in the tristate drivers/acpi/processor_driver.c. The node will be offlined when all memory/cpu on the node have been hotremoved. So we need the function try_offline_node() in cpu-hotplug path. If the memory-hotplug is disabled, and cpu-hotplug is enabled 1. no memory no the node we don't online the node, and cpu's node is the nearest node. 2. the node contains some memory the node has been onlined, and cpu's node is still needed to migrate the sleep task on the cpu to the same node. So we do nothing in try_offline_node() in this case. [rientjes@google.com: export the function try_offline_node() fix] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Len Brown <lenb@kernel.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: remove sysfs file of nodeTang Chen2013-02-231-1/+1
| | | | | | | | | | | | | | | | | | | | | Introduce a new function try_offline_node() to remove sysfs file of node when all memory sections of this node are removed. If some memory sections of this node are not removed, this function does nothing. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmapYasuaki Ishimatsu2013-02-231-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For removing memmap region of sparse-vmemmap which is allocated bootmem, memmap region of sparse-vmemmap needs to be registered by get_page_bootmem(). So the patch searches pages of virtual mapping and registers the pages by get_page_bootmem(). NOTE: register_page_bootmem_memmap() is not implemented for ia64, ppc, s390, and sparc. So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node() when platform doesn't support it. It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Since we have 2 config options called MEMORY_HOTPLUG and MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately, and codes in function register_page_bootmem_info_node() are only used for collecting infomation for hot-remove, so reside it under MEMORY_HOTREMOVE. Besides page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, move it too. [mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE] [linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()] [mhocko@suse.cz: remove the arch specific functions without any implementation] [linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed] [rientjes@google.com: fix defined but not used warning] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wu Jianguo <wujianguo@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: introduce new arch_remove_memory() for removing page tableWen Congyang2013-02-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | For removing memory, we need to remove page tables. But it depends on architecture. So the patch introduce arch_remove_memory() for removing page table. Now it only calls __remove_pages(). Note: __remove_pages() for some archtecuture is not implemented (I don't know how to implement it for s390). Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: check whether all memory blocks are offlined or not when ↵Yasuaki Ishimatsu2013-02-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | removing memory We remove the memory like this: 1. lock memory hotplug 2. offline a memory block 3. unlock memory hotplug 4. repeat 1-3 to offline all memory blocks 5. lock memory hotplug 6. remove memory(TODO) 7. unlock memory hotplug All memory blocks must be offlined before removing memory. But we don't hold the lock in the whole operation. So we should check whether all memory blocks are offlined before step6. Otherwise, kernel maybe panicked. Offlining a memory block and removing a memory device can be two different operations. Users can just offline some memory blocks without removing the memory device. For this purpose, the kernel has held lock_memory_hotplug() in __offline_pages(). To reuse the code for memory hot-remove, we repeat step 1-3 to offline all the memory blocks, repeatedly lock and unlock memory hotplug, but not hold the memory hotplug lock in the whole operation. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory-hotplug: dynamic configure movable memory and portion memoryLai Jiangshan2012-12-111-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add online_movable and online_kernel for logic memory hotplug. This is the dynamic version of "movablecore" & "kernelcore". We have the same reason to introduce it as to introduce "movablecore" & "kernelcore". It has the same motive as "movablecore" & "kernelcore", but it is dynamic/running-time: o We can configure memory as kernelcore or movablecore after boot. Userspace workload is increased, we need more hugepage, we can't use "online_movable" to add memory and allow the system use more THP(transparent-huge-page), vice-verse when kernel workload is increase. Also help for virtualization to dynamic configure host/guest's memory, to save/(reduce waste) memory. Memory capacity on Demand o When a new node is physically online after boot, we need to use "online_movable" or "online_kernel" to configure/portion it as we expected when we logic-online it. This configuration also helps for physically-memory-migrate. o all benefit as the same as existed "movablecore" & "kernelcore". o Preparing for movable-node, which is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). (Note, we don't introduce movable-node here.) Action behavior: When a memoryblock/memorysection is onlined by "online_movable", the kernel will not have directly reference to the page of the memoryblock, thus we can remove that memory any time when needed. When it is online by "online_kernel", the kernel can use it. When it is online by "online", the zone type doesn't changed. Current constraints: Only the memoryblock which is adjacent to the ZONE_MOVABLE can be online from ZONE_NORMAL to ZONE_MOVABLE. [akpm@linux-foundation.org: use min_t, cleanups] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: update memory block's state and notify userspaceWen Congyang2012-10-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | remove_memory() will be called when hot removing a memory device. But even if offlining memory, we cannot notice it. So the patch updates the memory block's state and sends notification to userspace. Additionally, the memory device may contain more than one memory block. If the memory block has been offlined, __offline_pages() will fail. So we should try to offline one memory block at a time. Thus remove_memory() also check each memory block's state. So there is no need to check the memory block's state before calling remove_memory(). Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: preparation to notify memory block's state at memory hot removeWen Congyang2012-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | remove_memory() is called in two cases: 1. echo offline >/sys/devices/system/memory/memoryXX/state 2. hot remove a memory device In the 1st case, the memory block's state is changed and the notification that memory block's state changed is sent to userland after calling remove_memory(). So user can notice memory block is changed. But in the 2nd case, the memory block's state is not changed and the notification is not also sent to userspcae even if calling remove_memory(). So user cannot notice memory block is changed. For adding the notification at memory hot remove, the patch just prepare as follows: 1st case uses offline_pages() for offlining memory. 2nd case uses remove_memory() for offlining memory and changing memory block's state and notifing the information. The patch does not implement notification to remove_memory(). Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker2012-03-041-0/+1
| | | | | | | | | | | | | If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* mm: extend memory hotplug API to allow memory hotplug in virtual machinesDaniel Kiper2011-07-251-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch contains online_page_callback and apropriate functions for registering/unregistering online page callbacks. It allows to do some machine specific tasks during online page stage which is required to implement memory hotplug in virtual machines. Currently this patch is required by latest memory hotplug support for Xen balloon driver patch which will be posted soon. Additionally, originial online_page() function was splited into following functions doing "atomic" operations: - __online_page_set_limits() - set new limits for memory management code, - __online_page_increment_counters() - increment totalram_pages and totalhigh_pages, - __online_page_free() - free page to allocator. It was done to: - not duplicate existing code, - ease hotplug code devolpment by usage of well defined interface, - avoid stupid bugs which are unavoidable when the same code (by design) is developed in many places. [akpm@linux-foundation.org: use explicit indirect-call syntax] Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'slub/hotplug' into slab/urgentPekka Enberg2011-01-151-0/+6
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