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* mm: refactor reinsert of swap_info in sys_swapoff()Cesar Eduardo Barros2012-12-111-9/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | The block within sys_swapoff() which re-inserts the swap_info into the swap_list in case of failure of try_to_unuse() reads a few values outside the swap_lock. While this is safe at that point, it is subtle code. Simplify the code by moving the reading of these values to a separate function, refactoring it a bit so they are read from within the swap_lock. This is easier to understand, and matches better the way it worked before I unified the insertion of the swap_info from both sys_swapon and sys_swapoff. This change should make no functional difference. The only real change is moving the read of two or three structure fields to within the lock (frontswap_map_get() is nothing more than a read of p->frontswap_map). Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm,vmscan: only evict file pages when we have plentyRik van Riel2012-12-111-2/+13
| | | | | | | | | | | | | | | | | | | | | | If we have more inactive file pages than active file pages, we skip scanning the active file pages altogether, with the idea that we do not want to evict the working set when there is plenty of streaming IO in the cache. However, the code forgot to also skip scanning anonymous pages in that situation. That leads to the curious situation of keeping the active file pages protected from being paged out when there are lots of inactive file pages, while still scanning and evicting anonymous pages. This patch fixes that situation, by only evicting file pages when we have plenty of them and most are inactive. [akpm@linux-foundation.org: adjust comment layout] Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> 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: add comment on storage key dirty bit semanticsJan Kara2012-12-111-3/+5
| | | | | | | | | | | | | Add comments that dirty bit in storage key gets set whenever page content is changed. Hopefully if someone will use this function, he'll have a look at one of the two places where we comment on this. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug.c: update start_pfn in zone and pg_data when spanned_pages ↵Tang Chen2012-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == 0. If we hot-remove memory only and leave the cpus alive, the corresponding node will not be removed. But the node_start_pfn and node_spanned_pages in pg_data will be reset to 0. In this case, when we hot-add the memory back next time, the node_start_pfn will always be 0 because no pfn is less than 0. After that, if we hot-remove the memory again, it will cause kernel panic in function find_biggest_section_pfn() when it tries to scan all the pfns. The zone will also have the same problem. This patch sets start_pfn to the start_pfn of the section being added when spanned_pages of the zone or pg_data is 0. ---How to reproduce--- 1. hot-add a container with some memory and cpus; 2. hot-remove the container's memory, and leave cpus there; 3. hot-add these memory again; 4. hot-remove them again; then, the kernel will panic. ---Call trace--- BUG: unable to handle kernel paging request at 00000fff82a8cc38 IP: [<ffffffff811c0d55>] find_biggest_section_pfn+0xe5/0x180 ...... Call Trace: [<ffffffff811c1124>] __remove_zone+0x184/0x1b0 [<ffffffff811c11dc>] __remove_section+0x8c/0xb0 [<ffffffff811c12e7>] __remove_pages+0xe7/0x120 [<ffffffff81654f7c>] arch_remove_memory+0x2c/0x80 [<ffffffff81655bb6>] remove_memory+0x56/0x90 [<ffffffff813da0c8>] acpi_memory_device_remove_memory+0x48/0x73 [<ffffffff813da55a>] acpi_memory_device_notify+0x153/0x274 [<ffffffff813b6786>] acpi_ev_notify_dispatch+0x41/0x5f [<ffffffff813a3867>] acpi_os_execute_deferred+0x27/0x34 [<ffffffff81090589>] process_one_work+0x219/0x680 [<ffffffff810923be>] worker_thread+0x12e/0x320 [<ffffffff81098396>] kthread+0xc6/0xd0 [<ffffffff8167c7c4>] kernel_thread_helper+0x4/0x10 ...... ---[ end trace 96d845dbf33fee11 ]--- Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slub, hotplug: ignore unrelated node's hot-adding and hot-removingLai Jiangshan2012-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SLUB only focuses on the nodes which have normal memory and it ignores the other node's hot-adding and hot-removing. Aka: if some memory of a node which has no onlined memory is online, but this new memory onlined is not normal memory (for example, highmem), we should not allocate kmem_cache_node for SLUB. And if the last normal memory is offlined, but the node still has memory, we should remove kmem_cache_node for that node. (The current code delays it when all of the memory is offlined) So we only do something when marg->status_change_nid_normal > 0. marg->status_change_nid is not suitable here. The same problem doesn't exist in SLAB, because SLAB allocates kmem_list3 for every node even the node don't have normal memory, SLAB tolerates kmem_list3 on alien nodes. SLUB only focuses on the nodes which have normal memory, it don't tolerate alien kmem_cache_node. The patch makes SLUB become self-compatible and avoids WARNs and BUGs in rare conditions. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Rob Landley <rob@landley.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory_hotplug: fix possible incorrect node_states[N_NORMAL_MEMORY]Lai Jiangshan2012-12-111-16/+120
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently memory_hotplug only manages the node_states[N_HIGH_MEMORY], it forgets to manage node_states[N_NORMAL_MEMORY]. This may cause node_states[N_NORMAL_MEMORY] to become incorrect. Example, if a node is empty before online, and we online a memory which is in ZONE_NORMAL. And after online, node_states[N_HIGH_MEMORY] is correct, but node_states[N_NORMAL_MEMORY] is incorrect, the online code doesn't set the new online node to node_states[N_NORMAL_MEMORY]. The same thing will happen when offlining (the offline code doesn't clear the node from node_states[N_NORMAL_MEMORY] when needed). Some memory managment code depends node_states[N_NORMAL_MEMORY], so we have to fix up the node_states[N_NORMAL_MEMORY]. We add node_states_check_changes_online() and node_states_check_changes_offline() to detect whether node_states[N_HIGH_MEMORY] and node_states[N_NORMAL_MEMORY] are changed while hotpluging. Also add @status_change_nid_normal to struct memory_notify, thus the memory hotplug callbacks know whether the node_states[N_NORMAL_MEMORY] are changed. (We can add a @flags and reuse @status_change_nid instead of introducing @status_change_nid_normal, but it will add much more complexity in memory hotplug callback in every subsystem. So introducing @status_change_nid_normal is better and it doesn't change the sematics of @status_change_nid) Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Rob Landley <rob@landley.net> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: allocate zone's pcp before onlining pagesWen Congyang2012-12-112-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | We use __free_page() to put a page to buddy system when onlining pages. __free_page() will store NR_FREE_PAGES in zone's pcp.vm_stat_diff, so we should allocate zone's pcp before onlining pages, otherwise we will lose some free pages. [mhocko@suse.cz: make zone_pcp_reset independent of MEMORY_HOTREMOVE] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug, mm/sparse.c: clear the memory to store struct pageWen Congyang2012-12-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If sparse memory vmemmap is enabled, we can't free the memory to store struct page when a memory device is hotremoved, because we may store struct page in the memory to manage the memory which doesn't belong to this memory device. When we hotadded this memory device again, we will reuse this memory to store struct page, and struct page may contain some obsolete information, and we will get bad-page state: init_memory_mapping: [mem 0x80000000-0x9fffffff] Built 2 zonelists in Node order, mobility grouping on. Total pages: 547617 Policy zone: Normal BUG: Bad page state in process bash pfn:9b6dc page:ffffea0002200020 count:0 mapcount:0 mapping: (null) index:0xfdfdfdfdfdfdfdfd page flags: 0x2fdfdfdfd5df9fd(locked|referenced|uptodate|dirty|lru|active|slab|owner_priv_1|private|private_2|writeback|head|tail|swapcache|reclaim|swapbacked|unevictable|uncached|compound_lock) Modules linked in: netconsole acpiphp pci_hotplug acpi_memhotplug loop kvm_amd kvm microcode tpm_tis tpm tpm_bios evdev psmouse serio_raw i2c_piix4 i2c_core parport_pc parport processor button thermal_sys ext3 jbd mbcache sg sr_mod cdrom ata_generic virtio_net ata_piix virtio_blk libata virtio_pci virtio_ring virtio scsi_mod Pid: 988, comm: bash Not tainted 3.6.0-rc7-guest #12 Call Trace: [<ffffffff810e9b30>] ? bad_page+0xb0/0x100 [<ffffffff810ea4c3>] ? free_pages_prepare+0xb3/0x100 [<ffffffff810ea668>] ? free_hot_cold_page+0x48/0x1a0 [<ffffffff8112cc08>] ? online_pages_range+0x68/0xa0 [<ffffffff8112cba0>] ? __online_page_increment_counters+0x10/0x10 [<ffffffff81045561>] ? walk_system_ram_range+0x101/0x110 [<ffffffff814c4f95>] ? online_pages+0x1a5/0x2b0 [<ffffffff8135663d>] ? __memory_block_change_state+0x20d/0x270 [<ffffffff81356756>] ? store_mem_state+0xb6/0xf0 [<ffffffff8119e482>] ? sysfs_write_file+0xd2/0x160 [<ffffffff8113769a>] ? vfs_write+0xaa/0x160 [<ffffffff81137977>] ? sys_write+0x47/0x90 [<ffffffff814e2f25>] ? async_page_fault+0x25/0x30 [<ffffffff814ea239>] ? system_call_fastpath+0x16/0x1b Disabling lock debugging due to kernel taint This patch clears the memory to store struct page to avoid unexpected error. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Minchan Kim <minchan.kim@gmail.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reported-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* numa: convert static memory to dynamically allocated memory for per node deviceWen Congyang2012-12-111-2/+2
| | | | | | | | | | | | | | | We use a static array to store struct node. In many cases, we don't have too many nodes, and some memory will be unused. Convert it to per-device dynamically allocated memory. Signed-off-by: Wen Congyang <wency@cn.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: 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: fix NR_FREE_PAGES mismatchWen Congyang2012-12-111-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | NR_FREE_PAGES will be wrong after offlining pages. We add/dec NR_FREE_PAGES like this now: 1. move all pages in buddy system to MIGRATE_ISOLATE, and dec NR_FREE_PAGES 2. don't add NR_FREE_PAGES when it is freed and the migratetype is MIGRATE_ISOLATE 3. dec NR_FREE_PAGES when offlining isolated pages. 4. add NR_FREE_PAGES when undoing isolate pages. When we come to step 3, all pages are in MIGRATE_ISOLATE list, and NR_FREE_PAGES are right. When we come to step4, all pages are not in buddy system, so we don't change NR_FREE_PAGES in this step, but we change NR_FREE_PAGES in step3. So NR_FREE_PAGES is wrong after offlining pages. So there is no need to change NR_FREE_PAGES in step3. This patch also fixs a problem in step2: if the migratetype is MIGRATE_ISOLATE, we should not add NR_FRR_PAGES when we remove pages from pcppages. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Jianguo Wu <wujianguo106@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: auto offline page_cgroup when onlining memory block failedWen Congyang2012-12-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | When a memory block is onlined, we will try allocate memory on that node to store page_cgroup. If onlining the memory block failed, we don't offline the page cgroup, and we have no chance to offline this page cgroup unless the memory block is onlined successfully again. It will cause that we can't hot-remove the memory device on that node, because some memory is used to store page cgroup. If onlining the memory block is failed, there is no need to stort page cgroup for this memory. So auto offline page_cgroup when onlining memory block failed. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: update mce_bad_pages when removing the memoryWen Congyang2012-12-111-0/+22
| | | | | | | | | | | | | | | | | | | | | When we hotremove a memory device, we will free the memory to store struct page. If the page is hwpoisoned page, we should decrease mce_bad_pages. [akpm@linux-foundation.org: cleanup ifdefs] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: skip HWPoisoned page when offlining pagesWen Congyang2012-12-114-14/+47
| | | | | | | | | | | | | | | | | | | | | | | | hwpoisoned may be set when we offline a page by the sysfs interface /sys/devices/system/memory/soft_offline_page or /sys/devices/system/memory/hard_offline_page. If we don't clear this flag when onlining pages, this page can't be freed, and will not in free list. So we can't offline these pages again. So we should skip such page when offlining pages. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: cleanup: introduce mk_huge_pmd()Bob Liu2012-12-111-9/+12
| | | | | | | | | | | | Introduce mk_huge_pmd() to simplify the code Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: introduce hugepage_vma_check()Bob Liu2012-12-111-21/+17
| | | | | | | | | | | | Multiple places do the same check. Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce mm_find_pmd()Bob Liu2012-12-115-92/+44
| | | | | | | | | | | | | | Several place need to find the pmd by(mm_struct, address), so introduce a function to simplify it. [akpm@linux-foundation.org: fix warning] Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: clean up __collapse_huge_page_isolateBob Liu2012-12-111-27/+11
| | | | | | | | | | | | | | There are duplicated places using release_pte_pages(). And release_all_pte_pages() can be removed. Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use IS_ENABLED(CONFIG_COMPACTION) instead of COMPACTION_BUILDKirill A. Shutemov2012-12-111-4/+5
| | | | | | | | | | | We don't need custom COMPACTION_BUILD anymore, since we have handy IS_ENABLED(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use IS_ENABLED(CONFIG_NUMA) instead of NUMA_BUILDKirill A. Shutemov2012-12-112-10/+12
| | | | | | | | | | | We don't need custom NUMA_BUILD anymore, since we have handy IS_ENABLED(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memcg: make mem_cgroup_out_of_memory() staticDavid Rientjes2012-12-111-2/+2
| | | | | | | | | | | mem_cgroup_out_of_memory() is only referenced from within file scope, so it can be marked static. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: show migration types in show_memRabin Vincent2012-12-111-2/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is useful to diagnose the reason for page allocation failure for cases where there appear to be several free pages. Example, with this alloc_pages(GFP_ATOMIC) failure: swapper/0: page allocation failure: order:0, mode:0x0 ... Mem-info: Normal per-cpu: CPU 0: hi: 90, btch: 15 usd: 48 CPU 1: hi: 90, btch: 15 usd: 21 active_anon:0 inactive_anon:0 isolated_anon:0 active_file:0 inactive_file:84 isolated_file:0 unevictable:0 dirty:0 writeback:0 unstable:0 free:4026 slab_reclaimable:75 slab_unreclaimable:484 mapped:0 shmem:0 pagetables:0 bounce:0 Normal free:16104kB min:2296kB low:2868kB high:3444kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:336kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:331776kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:300kB slab_unreclaimable:1936kB kernel_stack:328kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 Before the patch, it's hard (for me, at least) to say why all these free chunks weren't considered for allocation: Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 1*256kB 1*512kB 1*1024kB 1*2048kB 3*4096kB = 16128kB After the patch, it's obvious that the reason is that all of these are in the MIGRATE_CMA (C) freelist: Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 1*256kB (C) 1*512kB (C) 1*1024kB (C) 1*2048kB (C) 3*4096kB (C) = 16128kB Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: remove nr_pages_dirtied arg from balance_dirty_pages_ratelimited_nr()Namjae Jeon2012-12-111-6/+5
| | | | | | | | | | | | There is no reason to pass the nr_pages_dirtied argument, because nr_pages_dirtied value from the caller is unused in balance_dirty_pages_ratelimited_nr(). Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: dmapool: use provided gfp flags for all dma_alloc_coherent() callsMarek Szyprowski2012-12-111-24/+7
| | | | | | | | | | | | | | | | | | | | | | | dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag, regardless the flags provided by the caller. This causes excessive pruning of emergency memory pools without any good reason. Additionaly, on ARM architecture any driver which is using dmapools will sooner or later trigger the following error: "ERROR: 256 KiB atomic DMA coherent pool is too small! Please increase it with coherent_pool= kernel parameter!". Increasing the coherent pool size usually doesn't help much and only delays such error, because all GFP_ATOMIC DMA allocations are always served from the special, very limited memory pool. This patch changes the dmapool code to correctly use gfp flags provided by the dmapool caller. Reported-by: Soeren Moch <smoch@web.de> Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Soeren Moch <smoch@web.de> Cc: stable@vger.kernel.org
* Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damageLinus Torvalds2012-12-101-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commits a50915394f1fc02c2861d3b7ce7014788aa5066e and d7c3b937bdf45f0b844400b7bf6fd3ed50bac604. This is a revert of a revert of a revert. In addition, it reverts the even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the original commits in linux-next. It turns out that the original patch really was bogus, and that the original revert was the correct thing to do after all. We thought we had fixed the problem, and then reverted the revert, but the problem really is fundamental: waking up kswapd simply isn't the right thing to do, and direct reclaim sometimes simply _is_ the right thing to do. When certain allocations fail, we simply should try some direct reclaim, and if that fails, fail the allocation. That's the right thing to do for THP allocations, which can easily fail, and the GPU allocations want to do that too. So starting kswapd is sometimes simply wrong, and removing the flag that said "don't start kswapd" was a mistake. Let's hope we never revisit this mistake again - and certainly not this many times ;) Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "mm: avoid waking kswapd for THP allocations when compaction is ↵Linus Torvalds2012-12-101-27/+10
| | | | | | | | | | | | | | | | | | | | deferred or contended" This reverts commit 782fd30406ecb9d9b082816abe0c6008fc72a7b0. We are going to reinstate the __GFP_NO_KSWAPD flag that has been removed, the removal reverted, and then removed again. Making this commit a pointless fixup for a problem that was caused by the removal of __GFP_NO_KSWAPD flag. The thing is, we really don't want to wake up kswapd for THP allocations (because they fail quite commonly under any kind of memory pressure, including when there is tons of memory free), and these patches were just trying to fix up the underlying bug: the original removal of __GFP_NO_KSWAPD in commit c654345924f7 ("mm: remove __GFP_NO_KSWAPD") was simply bogus. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmscan: fix inappropriate zone congestion clearingJohannes Weiner2012-12-081-3/+0
| | | | | | | | | | | | | | | | | | | commit c702418f8a2f ("mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones") removed zone watermark checks from the compaction code in kswapd but left in the zone congestion clearing, which now happens unconditionally on higher order reclaim. This messes up the reclaim throttling logic for zones with dirty/writeback pages, where zones should only lose their congestion status when their watermarks have been restored. Remove the clearing from the zone compaction section entirely. The preliminary zone check and the reclaim loop in kswapd will clear it if the zone is considered balanced. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: fix shared mempolicy leakMel Gorman2012-12-062-32/+16
| | | | | | | | | | | | | | | | | | | | | | | This fixes a regression in 3.7-rc, which has since gone into stable. Commit 00442ad04a5e ("mempolicy: fix a memory corruption by refcount imbalance in alloc_pages_vma()") changed get_vma_policy() to raise the refcount on a shmem shared mempolicy; whereas shmem_alloc_page() went on expecting alloc_page_vma() to drop the refcount it had acquired. This deserves a rework: but for now fix the leak in shmem_alloc_page(). Hugh: shmem_swapin() did not need a fix, but surely it's clearer to use the same refcounting there as in shmem_alloc_page(), delete its onstack mempolicy, and the strange mpol_cond_copy() and __mpol_cond_copy() - those were invented to let swapin_readahead() make an unknown number of calls to alloc_pages_vma() with one mempolicy; but since 00442ad04a5e, alloc_pages_vma() has kept refcount in balance, so now no problem. Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmscan: do not keep kswapd looping forever due to individual ↵Johannes Weiner2012-12-061-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uncompactable zones When a zone meets its high watermark and is compactable in case of higher order allocations, it contributes to the percentage of the node's memory that is considered balanced. This requirement, that a node be only partially balanced, came about when kswapd was desparately trying to balance tiny zones when all bigger zones in the node had plenty of free memory. Arguably, the same should apply to compaction: if a significant part of the node is balanced enough to run compaction, do not get hung up on that tiny zone that might never get in shape. When the compaction logic in kswapd is reached, we know that at least 25% of the node's memory is balanced properly for compaction (see zone_balanced and pgdat_balanced). Remove the individual zone checks that restart the kswapd cycle. Otherwise, we may observe more endless looping in kswapd where the compaction code loops back to reclaim because of a single zone and reclaim does nothing because the node is considered balanced overall. See for example https://bugzilla.redhat.com/show_bug.cgi?id=866988 Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-and-tested-by: Thorsten Leemhuis <fedora@leemhuis.info> Reported-by: Jiri Slaby <jslaby@suse.cz> Tested-by: John Ellson <john.ellson@comcast.net> Tested-by: Zdenek Kabelac <zkabelac@redhat.com> Tested-by: Bruno Wolff III <bruno@wolff.to> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: compaction: validate pfn range passed to isolate_freepages_blockMel Gorman2012-12-061-1/+9
| | | | | | | | | | | | | | | | | | | | | | Commit 0bf380bc70ec ("mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during isolation for migration") added a check for pfn_valid() when isolating pages for migration as the scanner does not necessarily start pageblock-aligned. Since commit c89511ab2f8f ("mm: compaction: Restart compaction from near where it left off"), the free scanner has the same problem. This patch makes sure that the pfn range passed to isolate_freepages_block() is within the same block so that pfn_valid() checks are unnecessary. In answer to Henrik's wondering why others have not reported this: reproducing this requires a large enough hole with the right aligment to have compaction walk into a PFN range with no memmap. Size and alignment depends in the memory model - 4M for FLATMEM and 128M for SPARSEMEM on x86. It needs a "lucky" machine. Reported-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: soft offline: split thp at the beginning of soft_offline_page()Naoya Horiguchi2012-11-301-0/+8
| | | | | | | | | | | | | | | | When we try to soft-offline a thp tail page, put_page() is called on the tail page unthinkingly and VM_BUG_ON is triggered in put_compound_page(). This patch splits thp before going into the main body of soft-offlining. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: avoid waking kswapd for THP allocations when compaction is deferred or ↵Mel Gorman2012-11-301-10/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | contended With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" reverted, Zdenek Kabelac reported the following Hmm, so it's just took longer to hit the problem and observe kswapd0 spinning on my CPU again - it's not as endless like before - but still it easily eats minutes - it helps to turn off Firefox or TB (memory hungry apps) so kswapd0 stops soon - and restart those apps again. (And I still have like >1GB of cached memory) kswapd0 R running task 0 30 2 0x00000000 Call Trace: preempt_schedule+0x42/0x60 _raw_spin_unlock+0x55/0x60 put_super+0x31/0x40 drop_super+0x22/0x30 prune_super+0x149/0x1b0 shrink_slab+0xba/0x510 The sysrq+m indicates the system has no swap so it'll never reclaim anonymous pages as part of reclaim/compaction. That is one part of the problem but not the root cause as file-backed pages could also be reclaimed. The likely underlying problem is that kswapd is woken up or kept awake for each THP allocation request in the page allocator slow path. If compaction fails for the requesting process then compaction will be deferred for a time and direct reclaim is avoided. However, if there are a storm of THP requests that are simply rejected, it will still be the the case that kswapd is awake for a prolonged period of time as pgdat->kswapd_max_order is updated each time. This is noticed by the main kswapd() loop and it will not call kswapd_try_to_sleep(). Instead it will loopp, shrinking a small number of pages and calling shrink_slab() on each iteration. This patch defers when kswapd gets woken up for THP allocations. For !THP allocations, kswapd is always woken up. For THP allocations, kswapd is woken up iff the process is willing to enter into direct reclaim/compaction. [akpm@linux-foundation.org: fix typo in comment] Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Zdenek Kabelac <zkabelac@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "Revert "mm: remove __GFP_NO_KSWAPD""Andrew Morton2012-11-301-4/+3
| | | | | | | | | | | | | | | | It apepars that this patch was innocent, and we hope that "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" will fix the final kswapd-spinning cause. Cc: Zdenek Kabelac <zkabelac@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmscan: fix endless loop in kswapd balancingJohannes Weiner2012-11-301-9/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kswapd does not in all places have the same criteria for a balanced zone. Zones are only being reclaimed when their high watermark is breached, but compaction checks loop over the zonelist again when the zone does not meet the low watermark plus two times the size of the allocation. This gets kswapd stuck in an endless loop over a small zone, like the DMA zone, where the high watermark is smaller than the compaction requirement. Add a function, zone_balanced(), that checks the watermark, and, for higher order allocations, if compaction has enough free memory. Then use it uniformly to check for balanced zones. This makes sure that when the compaction watermark is not met, at least reclaim happens and progress is made - or the zone is declared unreclaimable at some point and skipped entirely. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: George Spelvin <linux@horizon.com> Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de> Reported-by: Tomas Racek <tracek@redhat.com> Tested-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/vmemmap: fix wrong use of virt_to_pageJianguo Wu2012-11-301-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I enable CONFIG_DEBUG_VIRTUAL and CONFIG_SPARSEMEM_VMEMMAP, when doing memory hotremove, there is a kernel BUG at arch/x86/mm/physaddr.c:20. It is caused by free_section_usemap()->virt_to_page(), virt_to_page() is only used for kernel direct mapping address, but sparse-vmemmap uses vmemmap address, so it is going wrong here. ------------[ cut here ]------------ kernel BUG at arch/x86/mm/physaddr.c:20! invalid opcode: 0000 [#1] SMP Modules linked in: acpihp_drv acpihp_slot edd cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse vfat fat loop dm_mod coretemp kvm crc32c_intel ipv6 ixgbe igb iTCO_wdt i7core_edac edac_core pcspkr iTCO_vendor_support ioatdma microcode joydev sr_mod i2c_i801 dca lpc_ich mfd_core mdio tpm_tis i2c_core hid_generic tpm cdrom sg tpm_bios rtc_cmos button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic ata_piix libata megaraid_sas scsi_mod CPU 39 Pid: 6454, comm: sh Not tainted 3.7.0-rc1-acpihp-final+ #45 QCI QSSC-S4R/QSSC-S4R RIP: 0010:[<ffffffff8103c908>] [<ffffffff8103c908>] __phys_addr+0x88/0x90 RSP: 0018:ffff8804440d7c08 EFLAGS: 00010006 RAX: 0000000000000006 RBX: ffffea0012000000 RCX: 000000000000002c ... Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Reviewd-by: Wen Congyang <wency@cn.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: compaction: fix return value of capture_free_page()Mel Gorman2012-11-301-1/+1
| | | | | | | | | | | | | | | Commit ef6c5be658f6 ("fix incorrect NR_FREE_PAGES accounting (appears like memory leak)") fixes a NR_FREE_PAGE accounting leak but missed the return value which was also missed by this reviewer until today. That return value is used by compaction when adding pages to a list of isolated free pages and without this follow-up fix, there is a risk of free list corruption. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmscan: check for fatal signals iff the process was throttledMel Gorman2012-11-261-10/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5515061d22f0 ("mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage") introduced a check for fatal signals after a process gets throttled for network storage. The intention was that if a process was throttled and got killed that it should not trigger the OOM killer. As pointed out by Minchan Kim and David Rientjes, this check is in the wrong place and too broad. If a system is in am OOM situation and a process is exiting, it can loop in __alloc_pages_slowpath() and calling direct reclaim in a loop. As the fatal signal is pending it returns 1 as if it is making forward progress and can effectively deadlock. This patch moves the fatal_signal_pending() check after throttling to throttle_direct_reclaim() where it belongs. If the process is killed while throttled, it will return immediately without direct reclaim except now it will have TIF_MEMDIE set and will use the PFMEMALLOC reserves. Minchan pointed out that it may be better to direct reclaim before returning to avoid using the reserves because there may be pages that can easily reclaim that would avoid using the reserves. However, we do no such targetted reclaim and there is no guarantee that suitable pages are available. As it is expected that this throttling happens when swap-over-NFS is used there is a possibility that the process will instead swap which may allocate network buffers from the PFMEMALLOC reserves. Hence, in the swap-over-nfs case where a process can be throtted and be killed it can use the reserves to exit or it can potentially use reserves to swap a few pages and then exit. This patch takes the option of using the reserves if necessary to allow the process exit quickly. If this patch passes review it should be considered a -stable candidate for 3.6. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "mm: remove __GFP_NO_KSWAPD"Mel Gorman2012-11-261-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" reverted, Zdenek Kabelac reported the following Hmm, so it's just took longer to hit the problem and observe kswapd0 spinning on my CPU again - it's not as endless like before - but still it easily eats minutes - it helps to turn off Firefox or TB (memory hungry apps) so kswapd0 stops soon - and restart those apps again. (And I still have like >1GB of cached memory) kswapd0 R running task 0 30 2 0x00000000 Call Trace: preempt_schedule+0x42/0x60 _raw_spin_unlock+0x55/0x60 put_super+0x31/0x40 drop_super+0x22/0x30 prune_super+0x149/0x1b0 shrink_slab+0xba/0x510 The sysrq+m indicates the system has no swap so it'll never reclaim anonymous pages as part of reclaim/compaction. That is one part of the problem but not the root cause as file-backed pages could also be reclaimed. The likely underlying problem is that kswapd is woken up or kept awake for each THP allocation request in the page allocator slow path. If compaction fails for the requesting process then compaction will be deferred for a time and direct reclaim is avoided. However, if there are a storm of THP requests that are simply rejected, it will still be the the case that kswapd is awake for a prolonged period of time as pgdat->kswapd_max_order is updated each time. This is noticed by the main kswapd() loop and it will not call kswapd_try_to_sleep(). Instead it will loopp, shrinking a small number of pages and calling shrink_slab() on each iteration. The temptation is to supply a patch that checks if kswapd was woken for THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not backed up by proper testing. As 3.7 is very close to release and this is not a bug we should release with, a safer path is to revert "mm: remove __GFP_NO_KSWAPD" for now and revisit it with the view to ironing out the balance_pgdat() logic in general. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Zdenek Kabelac <zkabelac@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix incorrect NR_FREE_PAGES accounting (appears like memory leak)Dave Hansen2012-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been some 3.7-rc reports of vm issues, including some kswapd bugs and, more importantly, some memory "leaks": http://www.spinics.net/lists/linux-mm/msg46187.html https://bugzilla.kernel.org/show_bug.cgi?id=50181 Commit 1fb3f8ca0e92 ("mm: compaction: capture a suitable high-order page immediately when it is made available") took split_free_page() and reused it for the compaction code. It does something curious with capture_free_page() (previously known as split_free_page()): int capture_free_page(struct page *page, int alloc_order, ... __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); - /* Split into individual pages */ - set_page_refcounted(page); - split_page(page, order); + if (alloc_order != order) + expand(zone, page, alloc_order, order, + &zone->free_area[order], migratetype); Note that expand() puts the pages _back_ in the allocator, but it does not bump NR_FREE_PAGES. We "return" 'alloc_order' worth of pages, but we accounted for removing 'order' in the __mod_zone_page_state() call. For the old split_page()-style use (order==alloc_order) the bug will not trigger. But, when called from the compaction code where we occasionally get a larger page out of the buddy allocator than we need, we will run in to this. This patch simply changes the NR_FREE_PAGES manipulation to the correct 'alloc_order' instead of 'order'. I've been able to repeatedly trigger this in my testing environment. The amount "leaked" very closely tracks the imbalance I see in buddy pages vs. NR_FREE_PAGES. I have confirmed that this patch fixes the imbalance Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "mm: fix-up zone present pages"Andrew Morton2012-11-164-53/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 7f1290f2f2a4 ("mm: fix-up zone present pages") That patch tried to fix a issue when calculating zone->present_pages, but it caused a regression on 32bit systems with HIGHMEM. With that change, reset_zone_present_pages() resets all zone->present_pages to zero, and fixup_zone_present_pages() is called to recalculate zone->present_pages when the boot allocator frees core memory pages into buddy allocator. Because highmem pages are not freed by bootmem allocator, all highmem zones' present_pages becomes zero. Various options for improving the situation are being discussed but for now, let's return to the 3.6 code. Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Chris Clayton <chris2553@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: change final i_blocks BUG to WARNINGHugh Dickins2012-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Under a particular load on one machine, I have hit shmem_evict_inode()'s BUG_ON(inode->i_blocks), enough times to narrow it down to a particular race between swapout and eviction. It comes from the "if (freed > 0)" asymmetry in shmem_recalc_inode(), and the lack of coherent locking between mapping's nrpages and shmem's swapped count. There's a window in shmem_writepage(), between lowering nrpages in shmem_delete_from_page_cache() and then raising swapped count, when the freed count appears to be +1 when it should be 0, and then the asymmetry stops it from being corrected with -1 before hitting the BUG. One answer is coherent locking: using tree_lock throughout, without info->lock; reasonable, but the raw_spin_lock in percpu_counter_add() on used_blocks makes that messier than expected. Another answer may be a further effort to eliminate the weird shmem_recalc_inode() altogether, but previous attempts at that failed. So far undecided, but for now change the BUG_ON to WARN_ON: in usual circumstances it remains a useful consistency check. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: fix shmem_getpage_gfp() VM_BUG_ONHugh Dickins2012-11-161-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fuzzing with trinity hit the "impossible" VM_BUG_ON(error) (which Fedora has converted to WARNING) in shmem_getpage_gfp(): WARNING: at mm/shmem.c:1151 shmem_getpage_gfp+0xa5c/0xa70() Pid: 29795, comm: trinity-child4 Not tainted 3.7.0-rc2+ #49 Call Trace: warn_slowpath_common+0x7f/0xc0 warn_slowpath_null+0x1a/0x20 shmem_getpage_gfp+0xa5c/0xa70 shmem_fault+0x4f/0xa0 __do_fault+0x71/0x5c0 handle_pte_fault+0x97/0xae0 handle_mm_fault+0x289/0x350 __do_page_fault+0x18e/0x530 do_page_fault+0x2b/0x50 page_fault+0x28/0x30 tracesys+0xe1/0xe6 Thanks to Johannes for pointing to truncation: free_swap_and_cache() only does a trylock on the page, so the page lock we've held since before confirming swap is not enough to protect against truncation. What cleanup is needed in this case? Just delete_from_swap_cache(), which takes care of the memcg uncharge. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Dave Jones <davej@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem addressWill Deacon2012-11-161-1/+1
| | | | | | | | | | | | | | | | | | kmap_to_page returns the corresponding struct page for a virtual address of an arbitrary mapping. This works by checking whether the address falls in the pkmap region and using the pkmap page tables instead of the linear mapping if appropriate. Unfortunately, the bounds checking means that PKMAP_ADDR(LAST_PKMAP) is incorrectly treated as a highmem address and we can end up walking off the end of pkmap_page_table and subsequently passing junk to pte_page. This patch fixes the bound check to stay within the pkmap tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: revert "mm: vmscan: scale number of pages reclaimed by ↵Mel Gorman2012-11-161-25/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reclaim/compaction based on failures" Jiri Slaby reported the following: (It's an effective revert of "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures".) Given kswapd had hours of runtime in ps/top output yesterday in the morning and after the revert it's now 2 minutes in sum for the last 24h, I would say, it's gone. The intention of the patch in question was to compensate for the loss of lumpy reclaim. Part of the reason lumpy reclaim worked is because it aggressively reclaimed pages and this patch was meant to be a sane compromise. When compaction fails, it gets deferred and both compaction and reclaim/compaction is deferred avoid excessive reclaim. However, since commit c654345924f7 ("mm: remove __GFP_NO_KSWAPD"), kswapd is woken up each time and continues reclaiming which was not taken into account when the patch was developed. Attempts to address the problem ended up just changing the shape of the problem instead of fixing it. The release window gets closer and while a THP allocation failing is not a major problem, kswapd chewing up a lot of CPU is. This patch reverts commit 83fde0f22872 ("mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures") and will be revisited in the future. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Zdenek Kabelac <zkabelac@redhat.com> Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* swapfile: fix name leak in swapoffXiaotian Feng2012-11-161-2/+2
| | | | | | | | | | | | | There's a name leak introduced by commit 91a27b2a7567 ("vfs: define struct filename and have getname() return it"). Add the missing putname. [akpm@linux-foundation.org: cleanup] Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix hotplugged memory zone oopsHugh Dickins2012-11-163-17/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When MEMCG is configured on (even when it's disabled by boot option), when adding or removing a page to/from its lru list, the zone pointer used for stats updates is nowadays taken from the struct lruvec. (On many configurations, calculating zone from page is slower.) But we have no code to update all the lruvecs (per zone, per memcg) when a memory node is hotadded. Here's an extract from the oops which results when running numactl to bind a program to a newly onlined node: BUG: unable to handle kernel NULL pointer dereference at 0000000000000f60 IP: __mod_zone_page_state+0x9/0x60 Pid: 1219, comm: numactl Not tainted 3.6.0-rc5+ #180 Bochs Bochs Process numactl (pid: 1219, threadinfo ffff880039abc000, task ffff8800383c4ce0) Call Trace: __pagevec_lru_add_fn+0xdf/0x140 pagevec_lru_move_fn+0xb1/0x100 __pagevec_lru_add+0x1c/0x30 lru_add_drain_cpu+0xa3/0x130 lru_add_drain+0x2f/0x40 ... The natural solution might be to use a memcg callback whenever memory is hotadded; but that solution has not been scoped out, and it happens that we do have an easy location at which to update lruvec->zone. The lruvec pointer is discovered either by mem_cgroup_zone_lruvec() or by mem_cgroup_page_lruvec(), and both of those do know the right zone. So check and set lruvec->zone in those; and remove the inadequate attempt to set lruvec->zone from lruvec_init(), which is called before NODE_DATA(node) has been allocated in such cases. Ah, there was one exceptionr. For no particularly good reason, mem_cgroup_force_empty_list() has its own code for deciding lruvec. Change it to use the standard mem_cgroup_zone_lruvec() and mem_cgroup_get_lru_size() too. In fact it was already safe against such an oops (the lru lists in danger could only be empty), but we're better proofed against future changes this way. I've marked this for stable (3.6) since we introduced the problem in 3.5 (now closed to stable); but I have no idea if this is the only fix needed to get memory hotadd working with memcg in 3.6, and received no answer when I enquired twice before. Reported-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: oom: fix totalpages calculation for memory.swappiness==0Michal Hocko2012-11-161-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | oom_badness() takes a totalpages argument which says how many pages are available and it uses it as a base for the score calculation. The value is calculated by mem_cgroup_get_limit which considers both limit and total_swap_pages (resp. memsw portion of it). This is usually correct but since fe35004fbf9e ("mm: avoid swapping out with swappiness==0") we do not swap when swappiness is 0 which means that we cannot really use up all the totalpages pages. This in turn confuses oom score calculation if the memcg limit is much smaller than the available swap because the used memory (capped by the limit) is negligible comparing to totalpages so the resulting score is too small if adj!=0 (typically task with CAP_SYS_ADMIN or non zero oom_score_adj). A wrong process might be selected as result. The problem can be worked around by checking mem_cgroup_swappiness==0 and not considering swap at all in such a case. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix build warning for uninitialized valueDavid Rientjes2012-11-161-6/+4
| | | | | | | | | | | | | | | | | | | do_wp_page() sets mmun_called if mmun_start and mmun_end were initialized and, if so, may call mmu_notifier_invalidate_range_end() with these values. This doesn't prevent gcc from emitting a build warning though: mm/memory.c: In function `do_wp_page': mm/memory.c:2530: warning: `mmun_start' may be used uninitialized in this function mm/memory.c:2531: warning: `mmun_end' may be used uninitialized in this function It's much easier to initialize the variables to impossible values and do a simple comparison to determine if they were initialized to remove the bool entirely. 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>
* mm: add anon_vma_lock to validate_mm()Michel Lespinasse2012-11-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Iterating over the vma->anon_vma_chain without anon_vma_lock may cause NULL ptr deref in anon_vma_interval_tree_verify(), because the node in the chain might have been removed. BUG: unable to handle kernel paging request at fffffffffffffff0 IP: [<ffffffff8122c29c>] anon_vma_interval_tree_verify+0xc/0xa0 PGD 4e28067 PUD 4e29067 PMD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU 0 Pid: 9050, comm: trinity-child64 Tainted: G W 3.7.0-rc2-next-20121025-sasha-00001-g673f98e-dirty #77 RIP: 0010: anon_vma_interval_tree_verify+0xc/0xa0 Process trinity-child64 (pid: 9050, threadinfo ffff880045f80000, task ffff880048eb0000) Call Trace: validate_mm+0x58/0x1e0 vma_adjust+0x635/0x6b0 __split_vma.isra.22+0x161/0x220 split_vma+0x24/0x30 sys_madvise+0x5da/0x7b0 tracesys+0xe1/0xe6 RIP anon_vma_interval_tree_verify+0xc/0xa0 CR2: fffffffffffffff0 Figured out by Bob Liu. Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()Takamori Yamaguchi2012-11-091-0/+2
| | | | | | | | | | | | | | | | In kswapd(), set current->reclaim_state to NULL before returning, as current->reclaim_state holds reference to variable on kswapd()'s stack. In rare cases, while returning from kswapd() during memory offlining, __free_slab() and freepages() can access the dangling pointer of current->reclaim_state. Signed-off-by: Takamori Yamaguchi <takamori.yamaguchi@jp.sony.com> Signed-off-by: Aaditya Kumar <aaditya.kumar@ap.sony.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2012-10-261-0/+24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "This fixes a couple of nasty page table initialization bugs which were causing kdump regressions. A clean rearchitecturing of the code is in the works - meanwhile these are reverts that restore the best-known-working state of the kernel. There's also EFI fixes and other small fixes." * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, mm: Undo incorrect revert in arch/x86/mm/init.c x86: efi: Turn off efi_enabled after setup on mixed fw/kernel x86, mm: Find_early_table_space based on ranges that are actually being mapped x86, mm: Use memblock memory loop instead of e820_RAM x86, mm: Trim memory in memblock to be page aligned x86/irq/ioapic: Check for valid irq_cfg pointer in smp_irq_move_cleanup_interrupt x86/efi: Fix oops caused by incorrect set_memory_uc() usage x86-64: Fix page table accounting Revert "x86/mm: Fix the size calculation of mapping tables" MAINTAINERS: Add EFI git repository location