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* mm,kdb,kgdb: Add a debug reference for the kdb kmap usageJason Wessel2010-08-051-0/+7
| | | | | | | | | | The kdb kmap should never get used outside of the kernel debugger exception context. Signed-off-by: Jason Wessel<jason.wessel@windriver.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Ingo Molnar <mingo@elte.hu> CC: linux-mm@kvack.org
* highmem: remove unneeded #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT for ↵Akinobu Mita2010-05-251-1/+1
| | | | | | | | | | | | | | | | | | | | debug_kmap_atomic() In f4112de6b679d84bd9b9681c7504be7bdfb7c7d5 ("mm: introduce debug_kmap_atomic") I said that debug_kmap_atomic() needs CONFIG_TRACE_IRQFLAGS_SUPPORT. It was wrong. (I thought irqs_disabled() is only available when the architecture has CONFIG_TRACE_IRQFLAGS_SUPPORT) Remove the #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT check to enable kmap_atomic() debugging for the architectures which do not have CONFIG_TRACE_IRQFLAGS_SUPPORT. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* grammar fix in commentUwe Kleine-König2010-02-051-1/+1
| | | | | | Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Nicolas Pitre <nico@marvell.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and ↵Soeren Sandmann2009-11-101-3/+10
| | | | | | | | | | | | | | | | KM_NMI_PTE Previously calling debug_kmap_atomic() with these types would cause spurious warnings. (triggered by SysProf using perf events) Signed-off-by: Soeren Sandmann Pedersen <sandmann@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: a.p.zijlstra@chello.nl Cc: <stable@kernel.org> # .31.x LKML-Reference: <ye8vdhz8krw.fsf@camel23.daimi.au.dk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* highmem: Fix race in debug_kmap_atomic() which could cause warn_count to ↵Soeren Sandmann2009-11-101-2/+2
| | | | | | | | | | | | | | | | | | | underflow debug_kmap_atomic() tries to prevent ever printing more than 10 warnings, but it does so by testing whether an unsigned integer is equal to 0. However, if the warning is caused by a nested IRQ, then this counter may underflow and the stream of warnings will never end. Fix that by using a signed integer instead. Signed-off-by: Soeren Sandmann Pedersen <sandmann@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: a.p.zijlstra@chello.nl Cc: <stable@kernel.org> # .31.x LKML-Reference: <ye8zl7b8ktj.fsf@camel23.daimi.au.dk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* block: remove some includings of blktrace_api.hLi Zefan2009-06-161-1/+0
| | | | | | | | When porting blktrace to tracepoints, we changed to trace/block.h for trace prober declarations. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* mm: introduce debug_kmap_atomicAkinobu Mita2009-04-011-0/+45
| | | | | | | | | | | | | | | | x86 has debug_kmap_atomic_prot() which is error checking function for kmap_atomic. It is usefull for the other architectures, although it needs CONFIG_TRACE_IRQFLAGS_SUPPORT. This patch exposes it to the other architectures. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* highmem: atomic highmem kmap page pinningNicolas Pitre2009-03-151-8/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most ARM machines have a non IO coherent cache, meaning that the dma_map_*() set of functions must clean and/or invalidate the affected memory manually before DMA occurs. And because the majority of those machines have a VIVT cache, the cache maintenance operations must be performed using virtual addresses. When a highmem page is kunmap'd, its mapping (and cache) remains in place in case it is kmap'd again. However if dma_map_page() is then called with such a page, some cache maintenance on the remaining mapping must be performed. In that case, page_address(page) is non null and we can use that to synchronize the cache. It is unlikely but still possible for kmap() to race and recycle the virtual address obtained above, and use it for another page before some on-going cache invalidation loop in dma_map_page() is done. In that case, the new mapping could end up with dirty cache lines for another page, and the unsuspecting cache invalidation loop in dma_map_page() might simply discard those dirty cache lines resulting in data loss. For example, let's consider this sequence of events: - dma_map_page(..., DMA_FROM_DEVICE) is called on a highmem page. --> - vaddr = page_address(page) is non null. In this case it is likely that the page has valid cache lines associated with vaddr. Remember that the cache is VIVT. --> for (i = vaddr; i < vaddr + PAGE_SIZE; i += 32) invalidate_cache_line(i); *** preemption occurs in the middle of the loop above *** - kmap_high() is called for a different page. --> - last_pkmap_nr wraps to zero and flush_all_zero_pkmaps() is called. The pkmap_count value for the page passed to dma_map_page() above happens to be 1, so the page is unmapped. But prior to that, flush_cache_kmaps() cleared the cache for it. So far so good. - A fresh pkmap entry is assigned for this kmap request. The Murphy law says this pkmap entry will eventually happen to use the same vaddr as the one which used to belong to the other page being processed by dma_map_page() in the preempted thread above. - The kmap_high() caller start dirtying the cache using the just assigned virtual mapping for its page. *** the first thread is rescheduled *** - The for(...) loop is resumed, but now cached data belonging to a different physical page is being discarded ! And this is not only a preemption issue as ARM can be SMP as well, making the above scenario just as likely. Hence the need for some kind of pkmap page pinning which can be used in any context, primarily for the benefit of dma_map_page() on ARM. This provides the necessary interface to cope with the above issue if ARCH_NEEDS_KMAP_HIGH_GET is defined, otherwise the resulting code is unchanged. Signed-off-by: Nicolas Pitre <nico@marvell.com> Reviewed-by: MinChan Kim <minchan.kim@gmail.com> Acked-by: Andrew Morton <akpm@linux-foundation.org>
* x86, pat: avoid highmem cache attribute aliasingNick Piggin2008-08-151-1/+4
| | | | | | | | | | | | | | | | | | | | Highmem code can leave ptes and tlb entries around for a given page even after kunmap, and after it has been freed. >From what I can gather, the PAT code may change the cache attributes of arbitrary physical addresses (ie. including highmem pages), which would result in aliases in the case that it operates on one of these lazy tlb highmem pages. Flushing kmaps should solve the problem. I've also just added code for conditional flushing if we haven't got any dangling highmem aliases -- this should help performance if we change page attributes frequently or systems that aren't using much highmem pages (eg. if < 4G RAM). Should be turned into 2 patches, but just for RFC... Signed-off-by: Ingo Molnar <mingo@elte.hu>
* highmem: Export totalhigh_pages.David S. Miller2008-07-191-0/+1
| | | | | | | | | Hash et al. sizing code in SCTP wants to make the calculation totalram_pages - totalhigh_pages, just like TCP. But this requires an export for the CONFIG_HIGHMEM case to work. Signed-off-by: David S. Miller <davem@davemloft.net>
* mm: highmem kernel-doc additionsRandy Dunlap2008-03-191-4/+26
| | | | | | | | Add kernel-doc comments to highmem.c. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove fastcall from mm/Harvey Harrison2008-02-051-2/+2
| | | | | | | | | fastcall is always defined to be empty, remove it [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Create the ZONE_MOVABLE zoneMel Gorman2007-07-171-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following 8 patches against 2.6.20-mm2 create a zone called ZONE_MOVABLE that is only usable by allocations that specify both __GFP_HIGHMEM and __GFP_MOVABLE. This has the effect of keeping all non-movable pages within a single memory partition while allowing movable allocations to be satisfied from either partition. The patches may be applied with the list-based anti-fragmentation patches that groups pages together based on mobility. The size of the zone is determined by a kernelcore= parameter specified at boot-time. This specifies how much memory is usable by non-movable allocations and the remainder is used for ZONE_MOVABLE. Any range of pages within ZONE_MOVABLE can be released by migrating the pages or by reclaiming. When selecting a zone to take pages from for ZONE_MOVABLE, there are two things to consider. First, only memory from the highest populated zone is used for ZONE_MOVABLE. On the x86, this is probably going to be ZONE_HIGHMEM but it would be ZONE_DMA on ppc64 or possibly ZONE_DMA32 on x86_64. Second, the amount of memory usable by the kernel will be spread evenly throughout NUMA nodes where possible. If the nodes are not of equal size, the amount of memory usable by the kernel on some nodes may be greater than others. By default, the zone is not as useful for hugetlb allocations because they are pinned and non-migratable (currently at least). A sysctl is provided that allows huge pages to be allocated from that zone. This means that the huge page pool can be resized to the size of ZONE_MOVABLE during the lifetime of the system assuming that pages are not mlocked. Despite huge pages being non-movable, we do not introduce additional external fragmentation of note as huge pages are always the largest contiguous block we care about. Credit goes to Andy Whitcroft for catching a large variety of problems during review of the patches. This patch creates an additional zone, ZONE_MOVABLE. This zone is only usable by allocations which specify both __GFP_HIGHMEM and __GFP_MOVABLE. Hot-added memory continues to be placed in their existing destination as there is no mechanism to redirect them to a specific zone. [y-goto@jp.fujitsu.com: Fix section mismatch of memory hotplug related code] [akpm@linux-foundation.org: various fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] i386: PARAVIRT: add kmap_atomic_pte for mapping highpte pagesJeremy Fitzhardinge2007-05-021-0/+9
| | | | | | | | | | | | | | | | | | | | | | Xen and VMI both have special requirements when mapping a highmem pte page into the kernel address space. These can be dealt with by adding a new kmap_atomic_pte() function for mapping highptes, and hooking it into the paravirt_ops infrastructure. Xen specifically wants to map the pte page RO, so this patch exposes a helper function, kmap_atomic_prot, which maps the page with the specified page protections. This also adds a kmap_flush_unused() function to clear out the cached kmap mappings. Xen needs this to clear out any potential stray RW mappings of pages which will become part of a pagetable. [ Zach - vmi.c will need some attention after this patch. It wasn't immediately obvious to me what needs to be done. ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
* [PATCH] Use ZVC for free_pagesChristoph Lameter2007-02-111-1/+2
| | | | | | | | | | | This is again simplifies some of the VM counter calculations through the use of the ZVC consolidated counters. [michal.k.k.piotrowski@gmail.com: build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] BLOCK: Separate the bounce buffering code from the highmem code [try #6]David Howells2006-09-301-281/+0
| | | | | | | | | | | Move the bounce buffer code from mm/highmem.c to mm/bounce.c so that it can be more easily disabled when the block layer is disabled. !!!NOTE!!! There may be a bug in this code: Should init_emergency_pool() be contingent on CONFIG_HIGHMEM? Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* [PATCH] reduce MAX_NR_ZONES: move HIGHMEM counters into highmem.c/.hChristoph Lameter2006-09-261-0/+13
| | | | | | | | | | | | | Move totalhigh_pages and nr_free_highpages() into highmem.c/.h Move the totalhigh_pages definition into highmem.c/.h. Move the nr_free_highpages function into highmem.c [yoichi_yuasa@tripeaks.co.jp: build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] zoned vm counters: conversion of nr_bounce to per zone counterChristoph Lameter2006-06-301-3/+3
| | | | | | | | | | | | | | Conversion of nr_bounce to a per zone counter nr_bounce is only used for proc output. So it could be left as an event counter. However, the event counters may not be accurate and nr_bounce is categorizing types of pages in a zone. So we really need this to also be a per zone counter. [akpm@osdl.org: bugfix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* BUG_ON() Conversion in mm/highmem.cEric Sesterhenn2006-04-021-10/+5
| | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] mempool: use common mempool page allocatorMatthew Dobson2006-03-261-16/+7
| | | | | | | | | | | Convert two mempool users that currently use their own mempool-backed page allocators to use the generic mempool page allocator. Also included are 2 trivial whitespace fixes. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23Jens Axboe2006-03-231-0/+3
| | | | Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] gfp_t: the restAl Viro2005-10-281-5/+9
| | | | | | | zone handling, mapping->flags handling Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] gfp flags annotations - part 1Al Viro2005-10-081-1/+1
| | | | | | | | | | | | - added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] count bounce buffer pages in vmstatKAMEZAWA Hiroyuki2005-05-011-0/+2
| | | | | | | | | | | | | | This is a patch for counting the number of pages for bounce buffers. It's shown in /proc/vmstat. Currently, the number of bounce pages are not counted anywhere. So, if there are many bounce pages, it seems that there are leaked pages. And it's difficult for a user to imagine the usage of bounce pages. So, it's meaningful to show # of bouce pages. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+607
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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