mm: cma: don't replace lowmem pages with highmem The filesystem layer expects pages in the block device's mapping to not be in highmem (the mapping's gfp mask is set in bdget()), but CMA can currently replace lowmem pages with highmem pages, leading to crashes in filesystem code such as the one below: Unable to handle kernel NULL pointer dereference at virtual address 00000400 pgd = c0c98000 [00000400] *pgd=00c91831, *pte=00000000, *ppte=00000000 Internal error: Oops: 817 [#1] PREEMPT SMP ARM CPU: 0 Not tainted (3.5.0-rc5+ #80) PC is at __memzero+0x24/0x80 ... Process fsstress (pid: 323, stack limit = 0xc0cbc2f0) Backtrace: [<c010e3f0>] (ext4_getblk+0x0/0x180) from [<c010e58c>] (ext4_bread+0x1c/0x98) [<c010e570>] (ext4_bread+0x0/0x98) from [<c0117944>] (ext4_mkdir+0x160/0x3bc) r4:c15337f0 [<c01177e4>] (ext4_mkdir+0x0/0x3bc) from [<c00c29e0>] (vfs_mkdir+0x8c/0x98) [<c00c2954>] (vfs_mkdir+0x0/0x98) from [<c00c2a60>] (sys_mkdirat+0x74/0xac) r6:00000000 r5:c152eb40 r4:000001ff r3:c14b43f0 [<c00c29ec>] (sys_mkdirat+0x0/0xac) from [<c00c2ab8>] (sys_mkdir+0x20/0x24) r6:beccdcf0 r5:00074000 r4:beccdbbc [<c00c2a98>] (sys_mkdir+0x0/0x24) from [<c000e3c0>] (ret_fast_syscall+0x0/0x30) Fix this by replacing only highmem pages with highmem. Reported-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
cma: fix migration mode __alloc_contig_migrate_range calls migrate_pages with wrong argument for migrate_mode. Fix it. Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks alloc_contig_range() performs memory allocation so it also should keep track on keeping the correct level of memory watermarks. This commit adds a call to *_slowpath style reclaim to grab enough pages to make sure that the final collection of contiguous pages from freelists will not starve the system. [notasas@gmail.com: update out_of_memory args] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> CC: Michal Nazarewicz <mina86@mina86.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: extract reclaim code from __alloc_pages_direct_reclaim() This patch extracts common reclaim code from __alloc_pages_direct_reclaim() function to separate function: __perform_reclaim() which can be later used by alloc_contig_range(). Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: Serialize access to min_free_kbytes There is a race between the min_free_kbytes sysctl, memory hotplug and transparent hugepage support enablement. Memory hotplug uses a zonelists_mutex to avoid a race when building zonelists. Reuse it to serialise watermark updates. [a.p.zijlstra@chello.nl: Older patch fixed the race with spinlock] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: page_isolation: MIGRATE_CMA isolation functions added This commit changes various functions that change pages and pageblocks migrate type between MIGRATE_ISOLATE and MIGRATE_MOVABLE in such a way as to allow to work with MIGRATE_CMA migrate type. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: mmzone: MIGRATE_CMA migration type added The MIGRATE_CMA migration type has two main characteristics: (i) only movable pages can be allocated from MIGRATE_CMA pageblocks and (ii) page allocator will never change migration type of MIGRATE_CMA pageblocks. This guarantees (to some degree) that page in a MIGRATE_CMA page block can always be migrated somewhere else (unless there's no memory left in the system). It is designed to be used for allocating big chunks (eg. 10MiB) of physically contiguous memory. Once driver requests contiguous memory, pages from MIGRATE_CMA pageblocks may be migrated away to create a contiguous block. To minimise number of migrations, MIGRATE_CMA migration type is the last type tried when page allocator falls back to other migration types when requested. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: page_alloc: change fallbacks array handling This commit adds a row for MIGRATE_ISOLATE type to the fallbacks array which was missing from it. It also, changes the array traversal logic a little making MIGRATE_RESERVE an end marker. The letter change, removes the implicit MIGRATE_UNMOVABLE from the end of each row which was read by __rmqueue_fallback() function. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: page_alloc: introduce alloc_contig_range() This commit adds the alloc_contig_range() function which tries to allocate given range of pages. It tries to migrate all already allocated pages that fall in the range thus freeing them. Once all pages in the range are freed they are removed from the buddy system thus allocated for the caller to use. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
mm: page_alloc: remove trailing whitespace Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie>
mm: fix off-by-two in __zone_watermark_ok() Commit 88f5acf88ae6 ("mm: page allocator: adjust the per-cpu counter threshold when memory is low") changed the form how free_pages is calculated but it forgot that we used to do free_pages - ((1 << order) - 1) so we ended up with off-by-two when calculating free_pages. Reported-by: Wang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: exclude reserved pages from dirtyable memory Per-zone dirty limits try to distribute page cache pages allocated for writing across zones in proportion to the individual zone sizes, to reduce the likelihood of reclaim having to write back individual pages from the LRU lists in order to make progress. This patch: The amount of dirtyable pages should not include the full number of free pages: there is a number of reserved pages that the page allocator and kswapd always try to keep free. The closer (reclaimable pages - dirty pages) is to the number of reserved pages, the more likely it becomes for reclaim to run into dirty pages: +----------+ --- | anon | | +----------+ | | | | | | -- dirty limit new -- flusher new | file | | | | | | | | | -- dirty limit old -- flusher old | | | +----------+ --- reclaim | reserved | +----------+ | kernel | +----------+ This patch introduces a per-zone dirty reserve that takes both the lowmem reserve as well as the high watermark of the zone into account, and a global sum of those per-zone values that is subtracted from the global amount of dirtyable pages. The lowmem reserve is unavailable to page cache allocations and kswapd tries to keep the high watermark free. We don't want to end up in a situation where reclaim has to clean pages in order to balance zones. Not treating reserved pages as dirtyable on a global level is only a conceptual fix. In reality, dirty pages are not distributed equally across zones and reclaim runs into dirty pages on a regular basis. But it is important to get this right before tackling the problem on a per-zone level, where the distance between reclaim and the dirty pages is mostly much smaller in absolute numbers. [akpm@linux-foundation.org: fix highmem build] Signed-off-by: Johannes Weiner <jweiner@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: more intensive memory corruption debugging With CONFIG_DEBUG_PAGEALLOC configured, the CPU will generate an exception on access (read,write) to an unallocated page, which permits us to catch code which corrupts memory. However the kernel is trying to maximise memory usage, hence there are usually few free pages in the system and buggy code usually corrupts some crucial data. This patch changes the buddy allocator to keep more free/protected pages and to interlace free/protected and allocated pages to increase the probability of catching corruption. When the kernel is compiled with CONFIG_DEBUG_PAGEALLOC, debug_guardpage_minorder defines the minimum order used by the page allocator to grant a request. The requested size will be returned with the remaining pages used as guard pages. The default value of debug_guardpage_minorder is zero: no change from current behaviour. [akpm@linux-foundation.org: tweak documentation, s/flg/flag/] Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: avoid livelock on !__GFP_FS allocations Colin Cross reported; Under the following conditions, __alloc_pages_slowpath can loop forever: gfp_mask & __GFP_WAIT is true gfp_mask & __GFP_FS is false reclaim and compaction make no progress order <= PAGE_ALLOC_COSTLY_ORDER These conditions happen very often during suspend and resume, when pm_restrict_gfp_mask() effectively converts all GFP_KERNEL allocations into __GFP_WAIT. The oom killer is not run because gfp_mask & __GFP_FS is false, but should_alloc_retry will always return true when order is less than PAGE_ALLOC_COSTLY_ORDER. In his fix, he avoided retrying the allocation if reclaim made no progress and __GFP_FS was not set. The problem is that this would result in GFP_NOIO allocations failing that previously succeeded which would be very unfortunate. The big difference between GFP_NOIO and suspend converting GFP_KERNEL to behave like GFP_NOIO is that normally flushers will be cleaning pages and kswapd reclaims pages allowing GFP_NOIO to succeed after a short delay. The same does not necessarily apply during suspend as the storage device may be suspended. This patch special cases the suspend case to fail the page allocation if reclaim cannot make progress and adds some documentation on how gfp_allowed_mask is currently used. Failing allocations like this may cause suspend to abort but that is better than a livelock. [mgorman@suse.de: Rework fix to be suspend specific] [rientjes@google.com: Move suspended device check to should_alloc_retry] Reported-by: Colin Cross <ccross@android.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm-tracepoint: rename page-free events Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into mm_page_free_batched Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct for all freed pages, not only for directly freed. So, let's name it properly. For pages freed via page-list we also trigger mm_page_free_batched event. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> 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: remove unused pagevec_free It not exported and now nobody uses it. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: add free_hot_cold_page_list() helper This patch adds helper free_hot_cold_page_list() to free list of 0-order pages. It frees pages directly from list without temporary page-vector. It also calls trace_mm_pagevec_free() to simulate pagevec_free() behaviour. bloat-o-meter: add/remove: 1/1 grow/shrink: 1/3 up/down: 267/-295 (-28) function old new delta free_hot_cold_page_list - 264 +264 get_page_from_freelist 2129 2132 +3 __pagevec_free 243 239 -4 split_free_page 380 373 -7 release_pages 606 510 -96 free_page_list 188 - -188 Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
switch debugfs to umode_t Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
mm: use aligned zone start for pfn_to_bitidx calculation commit c060f943d0929f3e429c5d9522290584f6281d6e upstream. The current calculation in pfn_to_bitidx assumes that (pfn - zone->zone_start_pfn) >> pageblock_order will return the same bit for all pfn in a pageblock. If zone_start_pfn is not aligned to pageblock_nr_pages, this may not always be correct. Consider the following with pageblock order = 10, zone start 2MB: pfn | pfn - zone start | (pfn - zone start) >> page block order ---------------------------------------------------------------- 0x26000 | 0x25e00 | 0x97 0x26100 | 0x25f00 | 0x97 0x26200 | 0x26000 | 0x98 0x26300 | 0x26100 | 0x98 This means that calling {get,set}_pageblock_migratetype on a single page will not set the migratetype for the full block. Fix this by rounding down zone_start_pfn when doing the bitidx calculation. For our use case, the effects of this bug were mostly tied to the fact that CMA allocations would either take a long time or fail to happen. Depending on the driver using CMA, this could result in anything from visual glitches to application failures. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm/page_alloc: fix the page address of higher page's buddy calculation commit 0ba8f2d59304dfe69b59c034de723ad80f7ab9ac upstream. The heuristic method for buddy has been introduced since commit 43506fad21ca ("mm/page_alloc.c: simplify calculation of combined index of adjacent buddy lists"). But the page address of higher page's buddy was wrongly calculated, which will lead page_is_buddy to fail for ever. IOW, the heuristic method would be disabled with the wrong page address of higher page's buddy. Calculating the page address of higher page's buddy should be based higher_page with the offset between index of higher page and index of higher page's buddy. Signed-off-by: Haifeng Li <omycle@gmail.com> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KyongHo Cho <pullip.cho@samsung.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>