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2015-09-08mm/hwpoison: fix race between soft_offline_page and unpoison_memoryWanpeng Li2-8/+5
Wanpeng Li reported a race between soft_offline_page() and unpoison_memory(), which causes the following kernel panic: BUG: Bad page state in process bash pfn:97000 page:ffffea00025c0000 count:0 mapcount:1 mapping: (null) index:0x7f4fdbe00 flags: 0x1fffff80080048(uptodate|active|swapbacked) page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: flags: 0x40(active) Modules linked in: snd_hda_codec_hdmi i915 rpcsec_gss_krb5 nfsv4 dns_resolver bnep rfcomm nfsd bluetooth auth_rpcgss nfs_acl nfs rfkill lockd grace sunrpc i2c_algo_bit drm_kms_helper snd_hda_codec_realtek snd_hda_codec_generic drm snd_hda_intel fscache snd_hda_codec x86_pkg_temp_thermal coretemp kvm_intel snd_hda_core snd_hwdep kvm snd_pcm snd_seq_dummy snd_seq_oss crct10dif_pclmul snd_seq_midi crc32_pclmul snd_seq_midi_event ghash_clmulni_intel snd_rawmidi aesni_intel lrw gf128mul snd_seq glue_helper ablk_helper snd_seq_device cryptd fuse snd_timer dcdbas serio_raw mei_me parport_pc snd mei ppdev i2c_core video lp soundcore parport lpc_ich shpchp mfd_core ext4 mbcache jbd2 sd_mod e1000e ahci ptp libahci crc32c_intel libata pps_core CPU: 3 PID: 2211 Comm: bash Not tainted 4.2.0-rc5-mm1+ #45 Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015 Call Trace: dump_stack+0x48/0x5c bad_page+0xe6/0x140 free_pages_prepare+0x2f9/0x320 ? uncharge_list+0xdd/0x100 free_hot_cold_page+0x40/0x170 __put_single_page+0x20/0x30 put_page+0x25/0x40 unmap_and_move+0x1a6/0x1f0 migrate_pages+0x100/0x1d0 ? kill_procs+0x100/0x100 ? unlock_page+0x6f/0x90 __soft_offline_page+0x127/0x2a0 soft_offline_page+0xa6/0x200 This race is explained like below: CPU0 CPU1 soft_offline_page __soft_offline_page TestSetPageHWPoison unpoison_memory PageHWPoison check (true) TestClearPageHWPoison put_page -> release refcount held by get_hwpoison_page in unpoison_memory put_page -> release refcount held by isolate_lru_page in __soft_offline_page migrate_pages The second put_page() releases refcount held by isolate_lru_page() which will lead to unmap_and_move() releases the last refcount of page and w/ mapcount still 1 since try_to_unmap() is not called if there is only one user map the page. Anyway, the page refcount and mapcount will still mess if the page is mapped by multiple users. This race was introduced by commit 4491f71260 ("mm/memory-failure: set PageHWPoison before migrate_pages()"), which focuses on preventing the reuse of successfully migrated page. Before this commit we prevent the reuse by changing the migratetype to MIGRATE_ISOLATE during soft offlining, which has the following problems, so simply reverting the commit is not a best option: 1) it doesn't eliminate the reuse completely, because set_migratetype_isolate() can fail to set MIGRATE_ISOLATE to the target page if the pageblock of the page contains one or more unmovable pages (i.e. has_unmovable_pages() returns true). 2) the original code changes migratetype to MIGRATE_ISOLATE forcibly, and sets it to MIGRATE_MOVABLE forcibly after soft offline, regardless of the original migratetype state, which could impact other subsystems like memory hotplug or compaction. This patch moves PageSetHWPoison just after put_page() in unmap_and_move(), which closes up the reported race window and minimizes another race window b/w SetPageHWPoison and reallocation (which causes the reuse of soft-offlined page.) The latter race window still exists but it's acceptable, because it's rare and effectively the same as ordinary "containment failure" case even if it happens, so keep the window open is acceptable. Fixes: 4491f71260 ("mm/memory-failure: set PageHWPoison before migrate_pages()") Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Wanpeng Li <wanpeng.li@hotmail.com> Tested-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: introduce num_poisoned_pages wrappersNaoya Horiguchi1-16/+14
num_poisoned_pages counter will be changed outside mm/memory-failure.c by a subsequent patch, so this patch prepares wrappers to manipulate it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Tested-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: replace most of put_page in memory error handling by ↵Wanpeng Li1-17/+15
put_hwpoison_page Replace most instances of put_page() in memory error handling with put_hwpoison_page(). Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: fix refcount of THP head page in no-injection caseWanpeng Li1-1/+1
Hwpoison injection takes a refcount of target page and another refcount of head page of THP if the target page is the tail page of a THP. However, current code doesn't release the refcount of head page if the THP is not supported to be injected wrt hwpoison filter. Fix it by reducing the refcount of head page if the target page is the tail page of a THP and it is not supported to be injected. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: introduce put_hwpoison_page to put refcount for memory error ↵Wanpeng Li1-0/+21
handling Introduce put_hwpoison_page to put refcount for memory error handling. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: fix PageHWPoison test/set raceWanpeng Li1-0/+2
There is a race between madvise_hwpoison path and memory_failure: CPU0 CPU1 madvise_hwpoison get_user_pages_fast PageHWPoison check (false) memory_failure TestSetPageHWPoison soft_offline_page PageHWPoison check (true) return -EBUSY (without put_page) Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hwpoison: fix failure to split thp w/ refcount heldWanpeng Li1-0/+2
THP pages will get a refcount in madvise_hwpoison() w/ MF_COUNT_INCREASED flag, however, the refcount is still held when fail to split THP pages. Fix it by reducing the refcount of THP pages when fail to split THP. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: add utility for early copy from unmapped ramMark Salter1-0/+22
When booting an arm64 kernel w/initrd using UEFI/grub, use of mem= will likely cut off part or all of the initrd. This leaves it outside the kernel linear map which leads to failure when unpacking. The x86 code has a similar need to relocate an initrd outside of mapped memory in some cases. The current x86 code uses early_memremap() to copy the original initrd from unmapped to mapped RAM. This patchset creates a generic copy_from_early_mem() utility based on that x86 code and has arm64 and x86 share it in their respective initrd relocation code. This patch (of 3): In some early boot circumstances, it may be necessary to copy from RAM outside the kernel linear mapping to mapped RAM. The need to relocate an initrd is one example in the x86 code. This patch creates a helper function based on current x86 code. Signed-off-by: Mark Salter <msalter@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, compaction: skip compound pages by order in free scannerVlastimil Babka1-0/+25
The compaction free scanner is looking for PageBuddy() pages and skipping all others. For large compound pages such as THP or hugetlbfs, we can save a lot of iterations if we skip them at once using their compound_order(). This is generally unsafe and we can read a bogus value of order due to a race, but if we are careful, the only danger is skipping too much. When tested with stress-highalloc from mmtests on 4GB system with 1GB hugetlbfs pages, the vmstat compact_free_scanned count decreased by at least 15%. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, compaction: always skip all compound pages by order in migrate scannerVlastimil Babka1-20/+27
The compaction migrate scanner tries to skip THP pages by their order, to reduce number of iterations for pages it cannot isolate. The check is only done if PageLRU() is true, which means it applies to THP pages, but not e.g. hugetlbfs pages or any other non-LRU compound pages, which we have to iterate by base pages. This limitation comes from the assumption that it's only safe to read compound_order() when we have the zone's lru_lock and THP cannot be split under us. But the only danger (after filtering out order values that are not below MAX_ORDER, to prevent overflows) is that we skip too much or too little after reading a bogus compound_order() due to a rare race. This is the same reasoning as patch 99c0fd5e51c4 ("mm, compaction: skip buddy pages by their order in the migrate scanner") introduced for unsafely reading PageBuddy() order. After this patch, all pages are tested for PageCompound() and we skip them by compound_order(). The test is done after the test for balloon_page_movable() as we don't want to assume if balloon pages (or other pages with own isolation and migration implementation if a generic API gets implemented) are compound or not. When tested with stress-highalloc from mmtests on 4GB system with 1GB hugetlbfs pages, the vmstat compact_migrate_scanned count decreased by 15%. [kirill.shutemov@linux.intel.com: change PageTransHuge checks to PageCompound for different series was squashed here] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, compaction: encapsulate resetting cached scanner positionsVlastimil Babka1-6/+10
Reseting the cached compaction scanner positions is now open-coded in __reset_isolation_suitable() and compact_finished(). Encapsulate the functionality in a new function reset_cached_positions(). Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, compaction: simplify handling restart position in free pages scannerVlastimil Babka1-15/+20
Handling the position where compaction free scanner should restart (stored in cc->free_pfn) got more complex with commit e14c720efdd7 ("mm, compaction: remember position within pageblock in free pages scanner"). Currently the position is updated in each loop iteration of isolate_freepages(), although it should be enough to update it only when breaking from the loop. There's also an extra check outside the loop updates the position in case we have met the migration scanner. This can be simplified if we move the test for having isolated enough from the for-loop header next to the test for contention, and determining the restart position only in these cases. We can reuse the isolate_start_pfn variable for this instead of setting cc->free_pfn directly. Outside the loop, we can simply set cc->free_pfn to current value of isolate_start_pfn without any extra check. Also add a VM_BUG_ON to catch possible mistake in the future, in case we later add a new condition that terminates isolate_freepages_block() prematurely without also considering the condition in isolate_freepages(). Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, compaction: more robust check for scanners meetingVlastimil Babka1-8/+14
Assorted compaction cleanups and optimizations. The interesting patches are 4 and 5. In 4, skipping of compound pages in single iteration is improved for migration scanner, so it works also for !PageLRU compound pages such as hugetlbfs, slab etc. Patch 5 introduces this kind of skipping in the free scanner. The trick is that we can read compound_order() without any protection, if we are careful to filter out values larger than MAX_ORDER. The only danger is that we skip too much. The same trick was already used for reading the freepage order in the migrate scanner. To demonstrate improvements of Patches 4 and 5 I've run stress-highalloc from mmtests, set to simulate THP allocations (including __GFP_COMP) on a 4GB system where 1GB was occupied by hugetlbfs pages. I'll include just the relevant stats: Patch 3 Patch 4 Patch 5 Compaction stalls 7523 7529 7515 Compaction success 323 304 322 Compaction failures 7200 7224 7192 Page migrate success 247778 264395 240737 Page migrate failure 15358 33184 21621 Compaction pages isolated 906928 980192 909983 Compaction migrate scanned 2005277 1692805 1498800 Compaction free scanned 13255284 11539986 9011276 Compaction cost 288 305 277 With 5 iterations per patch, the results are still noisy, but we can see that Patch 4 does reduce migrate_scanned by 15% thanks to skipping the hugetlbfs pages at once. Interestingly, free_scanned is also reduced and I have no idea why. Patch 5 further reduces free_scanned as expected, by 15%. Other stats are unaffected modulo noise. [1] https://lkml.org/lkml/2015/1/19/158 This patch (of 5): Compaction should finish when the migration and free scanner meet, i.e. they reach the same pageblock. Currently however, the test in compact_finished() simply just compares the exact pfns, which may yield a false negative when the free scanner position is in the middle of a pageblock and the migration scanner reaches the begining of the same pageblock. This hasn't been a problem until commit e14c720efdd7 ("mm, compaction: remember position within pageblock in free pages scanner") allowed the free scanner position to be in the middle of a pageblock between invocations. The hot-fix 1d5bfe1ffb5b ("mm, compaction: prevent infinite loop in compact_zone") prevented the issue by adding a special check in the migration scanner to satisfy the current detection of scanners meeting. However, the proper fix is to make the detection more robust. This patch introduces the compact_scanners_met() function that returns true when the free scanner position is in the same or lower pageblock than the migration scanner. The special case in isolate_migratepages() introduced by 1d5bfe1ffb5b is removed. Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: add support for __GFP_ZERO flag to dma_pool_alloc()Sean O. Stalley1-2/+7
Currently a call to dma_pool_alloc() with a ___GFP_ZERO flag returns a non-zeroed memory region. This patchset adds support for the __GFP_ZERO flag to dma_pool_alloc(), adds 2 wrapper functions for allocing zeroed memory from a pool, and provides a coccinelle script for finding & replacing instances of dma_pool_alloc() followed by memset(0) with a single dma_pool_zalloc() call. There was some concern that this always calls memset() to zero, instead of passing __GFP_ZERO into the page allocator. [https://lkml.org/lkml/2015/7/15/881] I ran a test on my system to get an idea of how often dma_pool_alloc() calls into pool_alloc_page(). After Boot: [ 30.119863] alloc_calls:541, page_allocs:7 After an hour: [ 3600.951031] alloc_calls:9566, page_allocs:12 After copying 1GB file onto a USB drive: [ 4260.657148] alloc_calls:17225, page_allocs:12 It doesn't look like dma_pool_alloc() calls down to the page allocator very often (at least on my system). This patch (of 4): Currently the __GFP_ZERO flag is ignored by dma_pool_alloc(). Make dma_pool_alloc() zero the memory if this flag is set. Signed-off-by: Sean O. Stalley <sean.stalley@intel.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Gilles Muller <Gilles.Muller@lip6.fr> Cc: Nicolas Palix <nicolas.palix@imag.fr> Cc: Michal Marek <mmarek@suse.cz> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08vmscan: fix increasing nr_isolated incurred by putback unevictable pagesJaewon Kim1-1/+1
reclaim_clean_pages_from_list() assumes that shrink_page_list() returns number of pages removed from the candidate list. But shrink_page_list() puts back mlocked pages without passing it to caller and without counting as nr_reclaimed. This increases nr_isolated. To fix this, this patch changes shrink_page_list() to pass unevictable pages back to caller. Caller will take care those pages. Minchan said: It fixes two issues. 1. With unevictable page, cma_alloc will be successful. Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. 2. fix leaking of NR_ISOLATED counter of vmstat With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL. Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@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>
2015-09-08mm: vmscan: never isolate more pages than necessaryVladimir Davydov1-1/+2
If transparent huge pages are enabled, we can isolate many more pages than we actually need to scan, because we count both single and huge pages equally in isolate_lru_pages(). Since commit 5bc7b8aca942d ("mm: thp: add split tail pages to shrink page list in page reclaim"), we scan all the tail pages immediately after a huge page split (see shrink_page_list()). As a result, we can reclaim up to SWAP_CLUSTER_MAX * HPAGE_PMD_NR (512 MB) in one run! This is easy to catch on memcg reclaim with zswap enabled. The latter makes swapout instant so that if we happen to scan an unreferenced huge page we will evict both its head and tail pages immediately, which is likely to result in excessive reclaim. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08bootmem: avoid freeing to bootmem after bootmem is doneChris Metcalf1-0/+7
Bootmem isn't popular any more, but some architectures still use it, and freeing to bootmem after calling free_all_bootmem_core() can end up scribbling over random memory. Instead, make sure the kernel generates a warning in this case by ensuring the node_bootmem_map field is non-NULL when are freeing or marking bootmem. An instance of this bug was just fixed in the tile architecture ("tile: use free_bootmem_late() for initrd") and catching this case more widely seems like a good thing. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Paul McQuade <paulmcquad@gmail.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, page_isolation: make set/unset_migratetype_isolate() file-localNaoya Horiguchi1-2/+3
Nowaday, set/unset_migratetype_isolate() is defined and used only in mm/page_isolation, so let's limit the scope within the file. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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>
2015-09-08mm/mempolicy.c: get rid of duplicated check for vma(VM_PFNMAP) in ↵Aristeu Rozanski1-3/+0
queue_pages_range() This check was introduced as part of 6f4576e3687 ("mempolicy: apply page table walker on queue_pages_range()") which got duplicated by 48684a65b4e ("mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)") by reintroducing it earlier on queue_page_test_walk() Signed-off-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.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>
2015-09-08mem-hotplug: handle node hole when initializing numa_meminfo.Tang Chen1-1/+1
When parsing SRAT, all memory ranges are added into numa_meminfo. In numa_init(), before entering numa_cleanup_meminfo(), all possible memory ranges are in numa_meminfo. And numa_cleanup_meminfo() removes all ranges over max_pfn or empty. But, this only works if the nodes are continuous. Let's have a look at the following example: We have an SRAT like this: SRAT: Node 0 PXM 0 [mem 0x00000000-0x5fffffff] SRAT: Node 0 PXM 0 [mem 0x100000000-0x1ffffffffff] SRAT: Node 1 PXM 1 [mem 0x20000000000-0x3ffffffffff] SRAT: Node 4 PXM 2 [mem 0x40000000000-0x5ffffffffff] hotplug SRAT: Node 5 PXM 3 [mem 0x60000000000-0x7ffffffffff] hotplug SRAT: Node 2 PXM 4 [mem 0x80000000000-0x9ffffffffff] hotplug SRAT: Node 3 PXM 5 [mem 0xa0000000000-0xbffffffffff] hotplug SRAT: Node 6 PXM 6 [mem 0xc0000000000-0xdffffffffff] hotplug SRAT: Node 7 PXM 7 [mem 0xe0000000000-0xfffffffffff] hotplug On boot, only node 0,1,2,3 exist. And the numa_meminfo will look like this: numa_meminfo.nr_blks = 9 1. on node 0: [0, 60000000] 2. on node 0: [100000000, 20000000000] 3. on node 1: [20000000000, 40000000000] 4. on node 4: [40000000000, 60000000000] 5. on node 5: [60000000000, 80000000000] 6. on node 2: [80000000000, a0000000000] 7. on node 3: [a0000000000, a0800000000] 8. on node 6: [c0000000000, a0800000000] 9. on node 7: [e0000000000, a0800000000] And numa_cleanup_meminfo() will merge 1 and 2, and remove 8,9 because the end address is over max_pfn, which is a0800000000. But 4 and 5 are not removed because their end addresses are less then max_pfn. But in fact, node 4 and 5 don't exist. In a word, numa_cleanup_meminfo() is not able to handle holes between nodes. Since memory ranges in node 4 and 5 are in numa_meminfo, in numa_register_memblks(), node 4 and 5 will be mistakenly set to online. If you run lscpu, it will show: NUMA node0 CPU(s): 0-14,128-142 NUMA node1 CPU(s): 15-29,143-157 NUMA node2 CPU(s): NUMA node3 CPU(s): NUMA node4 CPU(s): 62-76,190-204 NUMA node5 CPU(s): 78-92,206-220 In this patch, we use memblock_overlaps_region() to check if ranges in numa_meminfo overlap with ranges in memory_block. Since memory_block contains all available memory at boot time, if they overlap, it means the ranges exist. If not, then remove them from numa_meminfo. After this patch, lscpu will show: NUMA node0 CPU(s): 0-14,128-142 NUMA node1 CPU(s): 15-29,143-157 NUMA node4 CPU(s): 62-76,190-204 NUMA node5 CPU(s): 78-92,206-220 Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/memblock.c: make memblock_overlaps_region() return bool.Tang Chen1-5/+5
memblock_overlaps_region() checks if the given memblock region intersects a region in memblock. If so, it returns the index of the intersected region. But its only caller is memblock_is_region_reserved(), and it returns 0 if false, non-zero if true. Both of these should return bool. Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: madvise allow remove operation for hugetlbfsMike Kravetz1-1/+1
Now that we have hole punching support for hugetlbfs, we can also support the MADV_REMOVE interface to it. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08hugetlbfs: add hugetlbfs_fallocate()Mike Kravetz1-1/+1
This is based on the shmem version, but it has diverged quite a bit. We have no swap to worry about, nor the new file sealing. Add synchronication via the fault mutex table to coordinate page faults, fallocate allocation and fallocate hole punch. What this allows us to do is move physical memory in and out of a hugetlbfs file without having it mapped. This also gives us the ability to support MADV_REMOVE since it is currently implemented using fallocate(). MADV_REMOVE lets madvise() remove pages from the middle of a hugetlbfs file, which wasn't possible before. hugetlbfs fallocate only operates on whole huge pages. Based on code by Dave Hansen. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08hugetlbfs: New huge_add_to_page_cache helper routineMike Kravetz1-9/+18
Currently, there is only a single place where hugetlbfs pages are added to the page cache. The new fallocate code be adding a second one, so break the functionality out into its own helper. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hugetlb: alloc_huge_page handle areas hole punched by fallocateMike Kravetz1-15/+39
Areas hole punched by fallocate will not have entries in the region/reserve map. However, shared mappings with min_size subpool reservations may still have reserved pages. alloc_huge_page needs to handle this special case and do the proper accounting. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hugetlb: vma_has_reserves() needs to handle fallocate hole punchMike Kravetz1-2/+13
In vma_has_reserves(), the current assumption is that reserves are always present for shared mappings. However, this will not be the case with fallocate hole punch. When punching a hole, the present page will be deleted as well as the region/reserve map entry (and hence any reservation). vma_has_reserves is passed "chg" which indicates whether or not a region/reserve map is present. Use this to determine if reserves are actually present or were removed via hole punch. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08hugetlbfs: truncate_hugepages() takes a range of pagesMike Kravetz1-3/+37
Modify truncate_hugepages() to take a range of pages (start, end) instead of simply start. If an end value of LLONG_MAX is passed, the current "truncate" functionality is maintained. Existing callers are modified to pass LLONG_MAX as end of range. By keying off end == LLONG_MAX, the routine behaves differently for truncate and hole punch. Page removal is now synchronized with page allocation via faults by using the fault mutex table. The hole punch case can experience the rare region_del error and must handle accordingly. Add the routine hugetlb_fix_reserve_counts to fix up reserve counts in the case where region_del returns an error. Since the routine handles more than just the truncate case, it is renamed to remove_inode_hugepages(). To be consistent, the routine truncate_huge_page() is renamed remove_huge_page(). Downstream of remove_inode_hugepages(), the routine hugetlb_unreserve_pages() is also modified to take a range of pages. hugetlb_unreserve_pages is modified to detect an error from region_del and pass it back to the caller. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hugetlb: expose hugetlb fault mutex for use by fallocateMike Kravetz1-10/+10
hugetlb page faults are currently synchronized by the table of mutexes (htlb_fault_mutex_table). fallocate code will need to synchronize with the page fault code when it allocates or deletes pages. Expose interfaces so that fallocate operations can be synchronized with page faults. Minor name changes to be more consistent with other global hugetlb symbols. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hugetlb: add region_del() to delete a specific range of entriesMike Kravetz1-37/+85
fallocate hole punch will want to remove a specific range of pages. The existing region_truncate() routine deletes all region/reserve map entries after a specified offset. region_del() will provide this same functionality if the end of region is specified as LONG_MAX. Hence, region_del() can replace region_truncate(). Unlike region_truncate(), region_del() can return an error in the rare case where it can not allocate memory for a region descriptor. This ONLY happens in the case where an existing region must be split. Current callers passing LONG_MAX as end of range will never experience this error and do not need to deal with error handling. Future callers of region_del() (such as fallocate hole punch) will need to handle this error. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/hugetlb: add cache of descriptors to resv_map for region_addMike Kravetz1-22/+152
hugetlbfs is used today by applications that want a high degree of control over huge page usage. Often, large hugetlbfs files are used to map a large number huge pages into the application processes. The applications know when page ranges within these large files will no longer be used, and ideally would like to release them back to the subpool or global pools for other uses. The fallocate() system call provides an interface for preallocation and hole punching within files. This patch set adds fallocate functionality to hugetlbfs. fallocate hole punch will want to remove a specific range of pages. When pages are removed, their associated entries in the region/reserve map will also be removed. This will break an assumption in the region_chg/region_add calling sequence. If a new region descriptor must be allocated, it is done as part of the region_chg processing. In this way, region_add can not fail because it does not need to attempt an allocation. To prepare for fallocate hole punch, create a "cache" of descriptors that can be used by region_add if necessary. region_chg will ensure there are sufficient entries in the cache. It will be necessary to track the number of in progress add operations to know a sufficient number of descriptors reside in the cache. A new routine region_abort is added to adjust this in progress count when add operations are aborted. vma_abort_reservation is also added for callers creating reservations with vma_needs_reservation/vma_commit_reservation. [akpm@linux-foundation.org: fix typo in comment, use more cols] Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: rename and move get/set_freepage_migratetypeVlastimil Babka1-13/+28
The pair of get/set_freepage_migratetype() functions are used to cache pageblock migratetype for a page put on a pcplist, so that it does not have to be retrieved again when the page is put on a free list (e.g. when pcplists become full). Historically it was also assumed that the value is accurate for pages on freelists (as the functions' names unfortunately suggest), but that cannot be guaranteed without affecting various allocator fast paths. It is in fact not needed and all such uses have been removed. The last remaining (but pointless) usage related to pages of freelists is in move_freepages(), which this patch removes. To prevent further confusion, rename the functions to get/set_pcppage_migratetype() and expand their description. Since all the users are now in mm/page_alloc.c, move the functions there from the shared header. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Laura Abbott <lauraa@codeaurora.org> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Seungho Park <seungho1.park@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, page_isolation: remove bogus tests for isolated pagesVlastimil Babka2-24/+10
The __test_page_isolated_in_pageblock() is used to verify whether all pages in pageblock were either successfully isolated, or are hwpoisoned. Two of the possible state of pages, that are tested, are however bogus and misleading. Both tests rely on get_freepage_migratetype(page), which however has no guarantees about pages on freelists. Specifically, it doesn't guarantee that the migratetype returned by the function actually matches the migratetype of the freelist that the page is on. Such guarantee is not its purpose and would have negative impact on allocator performance. The first test checks whether the freepage_migratetype equals MIGRATE_ISOLATE, supposedly to catch races between page isolation and allocator activity. These races should be fixed nowadays with 51bb1a4093 ("mm/page_alloc: add freepage on isolate pageblock to correct buddy list") and related patches. As explained above, the check wouldn't be able to catch them reliably anyway. For the same reason false positives can happen, although they are harmless, as the move_freepages() call would just move the page to the same freelist it's already on. So removing the test is not a bug fix, just cleanup. After this patch, we assume that all PageBuddy pages are on the correct freelist and that the races were really fixed. A truly reliable verification in the form of e.g. VM_BUG_ON() would be complicated and is arguably not needed. The second test (page_count(page) == 0 && get_freepage_migratetype(page) == MIGRATE_ISOLATE) is probably supposed (the code comes from a big memory isolation patch from 2007) to catch pages on MIGRATE_ISOLATE pcplists. However, pcplists don't contain MIGRATE_ISOLATE freepages nowadays, those are freed directly to free lists, so the check is obsolete. Remove it as well. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Laura Abbott <lauraa@codeaurora.org> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Seungho Park <seungho1.park@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08memcg: move memcg_proto_active from sock.hMichal Hocko1-1/+1
The only user is sock_update_memcg which is living in memcontrol.c so it doesn't make much sense to pollute sock.h by this inline helper. Move it to memcontrol.c and open code it into its only caller. Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08memcg, tcp_kmem: check for cg_proto in sock_update_memcgMichal Hocko1-2/+1
sk_prot->proto_cgroup is allowed to return NULL but sock_update_memcg doesn't check for NULL. The function relies on the mem_cgroup_is_root check because we shouldn't get NULL otherwise because mem_cgroup_from_task will always return !NULL. All other callers are checking for NULL and we can safely replace mem_cgroup_is_root() check by cg_proto != NULL which will be more straightforward (proto_cgroup returns NULL for the root memcg already). Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08memcg: restructure mem_cgroup_can_attach()Tejun Heo1-29/+32
Restructure it to lower nesting level and help the planned threadgroup leader iteration changes. This is pure reorganization. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Vladimir Davydov <vdavydov@parallels.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>
2015-09-08memcg: export struct mem_cgroupMichal Hocko4-316/+5
mem_cgroup structure is defined in mm/memcontrol.c currently which means that the code outside of this file has to use external API even for trivial access stuff. This patch exports mm_struct with its dependencies and makes some of the exported functions inlines. This even helps to reduce the code size a bit (make defconfig + CONFIG_MEMCG=y) text data bss dec hex filename 12355346 1823792 1089536 15268674 e8fb42 vmlinux.before 12354970 1823792 1089536 15268298 e8f9ca vmlinux.after This is not much (370B) but better than nothing. We also save a function call in some hot paths like callers of mem_cgroup_count_vm_event which is used for accounting. The patch doesn't introduce any functional changes. [vdavykov@parallels.com: inline memcg_kmem_is_active] [vdavykov@parallels.com: do not expose type outside of CONFIG_MEMCG] [akpm@linux-foundation.org: memcontrol.h needs eventfd.h for eventfd_ctx] [akpm@linux-foundation.org: export mem_cgroup_from_task() to modules] Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy()Sergey Senozhatsky1-0/+3
dma_pool_destroy() does not tolerate a NULL dma_pool pointer argument and performs a NULL-pointer dereference. This requires additional attention and effort from developers/reviewers and forces all dma_pool_destroy() callers to do a NULL check if (pool) dma_pool_destroy(pool); Or, otherwise, be invalid dma_pool_destroy() users. Tweak dma_pool_destroy() and NULL-check the pointer there. Proposed by Andrew Morton. Link: https://lkml.org/lkml/2015/6/8/583 Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/mempool: allow NULL `pool' pointer in mempool_destroy()Sergey Senozhatsky1-0/+3
mempool_destroy() does not tolerate a NULL mempool_t pointer argument and performs a NULL-pointer dereference. This requires additional attention and effort from developers/reviewers and forces all mempool_destroy() callers to do a NULL check if (pool) mempool_destroy(pool); Or, otherwise, be invalid mempool_destroy() users. Tweak mempool_destroy() and NULL-check the pointer there. Proposed by Andrew Morton. Link: https://lkml.org/lkml/2015/6/8/583 Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()Sergey Senozhatsky1-0/+3
kmem_cache_destroy() does not tolerate a NULL kmem_cache pointer argument and performs a NULL-pointer dereference. This requires additional attention and effort from developers/reviewers and forces all kmem_cache_destroy() callers (200+ as of 4.1) to do a NULL check if (cache) kmem_cache_destroy(cache); Or, otherwise, be invalid kmem_cache_destroy() users. Tweak kmem_cache_destroy() and NULL-check the pointer there. Proposed by Andrew Morton. Link: https://lkml.org/lkml/2015/6/8/583 Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, oom: remove unnecessary variableDavid Rientjes1-13/+8
The "killed" variable in out_of_memory() can be removed since the call to oom_kill_process() where we should block to allow the process time to exit is obvious. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, oom: do not panic for oom kills triggered from sysrqDavid Rientjes1-2/+5
Sysrq+f is used to kill a process either for debug or when the VM is otherwise unresponsive. It is not intended to trigger a panic when no process may be killed. Avoid panicking the system for sysrq+f when no processes are killed. Signed-off-by: David Rientjes <rientjes@google.com> Suggested-by: Michal Hocko <mhocko@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, oom: pass an oom order of -1 when triggered by sysrqDavid Rientjes3-5/+2
The force_kill member of struct oom_control isn't needed if an order of -1 is used instead. This is the same as order == -1 in struct compact_control which requires full memory compaction. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, oom: organize oom context into structDavid Rientjes3-68/+73
There are essential elements to an oom context that are passed around to multiple functions. Organize these elements into a new struct, struct oom_control, that specifies the context for an oom condition. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: make set_recommended_min_free_kbytes() return voidNicholas Krause1-2/+1
This makes set_recommended_min_free_kbytes() have a return type of void as it cannot fail. Signed-off-by: Nicholas Krause <xerofoify@gmail.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>
2015-09-08fs: do not prefault sys_write() user buffer pagesDave Hansen1-16/+18
=== Short summary ==== iov_iter_fault_in_readable() works around a really rare case and we can avoid the deadlock it addresses in another way: disable page faults and work around copy failures by faulting after the copy in a slow path instead of before in a hot one. I have a little microbenchmark that does repeated, small writes to tmpfs. This patch speeds that micro up by 6.2%. === Long version === When doing a sys_write() we have a source buffer in userspace and then a target file page. If both of those are the same physical page, there is a potential deadlock that we avoid. It would happen something like this: 1. We start the write to the file 2. Allocate page cache page and set it !Uptodate 3. Touch the userspace buffer to copy in the user data 4. Page fault (since source of the write not yet mapped) 5. Page fault code tries to lock the page and deadlocks (more details on this below) To avoid this, we prefault the page to guarantee that this fault does not occur. But, this prefault comes at a cost. It is one of the most expensive things that we do in a hot write() path (especially if we compare it to the read path). It is working around a pretty rare case. To fix this, it's pretty simple. We move the "prefault" code to run after we attempt the copy. We explicitly disable page faults _during_ the copy, detect the copy failure, then execute the "prefault" ouside of where the page lock needs to be held. iov_iter_copy_from_user_atomic() actually already has an implicit pagefault_disable() inside of it (at least on x86), but we add an explicit one. I don't think we can depend on every kmap_atomic() implementation to pagefault_disable() for eternity. =================================================== The stack trace when this happens looks like this: wait_on_page_bit_killable+0xc0/0xd0 __lock_page_or_retry+0x84/0xa0 filemap_fault+0x1ed/0x3d0 __do_fault+0x41/0xc0 handle_mm_fault+0x9bb/0x1210 __do_page_fault+0x17f/0x3d0 do_page_fault+0xc/0x10 page_fault+0x22/0x30 generic_perform_write+0xca/0x1a0 __generic_file_write_iter+0x190/0x1f0 ext4_file_write_iter+0xe9/0x460 __vfs_write+0xaa/0xe0 vfs_write+0xa6/0x1a0 SyS_write+0x46/0xa0 entry_SYSCALL_64_fastpath+0x12/0x6a 0xffffffffffffffff (Note, this does *NOT* happen in practice today because the kmap_atomic() does a pagefault_disable(). The trace above was obtained by taking out the pagefault_disable().) You can trigger the deadlock with this little code snippet: fd = open("foo", O_RDWR); fdmap = mmap(NULL, len, PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0); write(fd, &fdmap[0], 1); Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jens Axboe <axboe@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: NeilBrown <neilb@suse.de> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Paul Cassella <cassella@cray.com> Cc: Greg Thelen <gthelen@google.com> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: /proc/pid/smaps:: show proportional swap share of the mappingMinchan Kim1-0/+42
We want to know per-process workingset size for smart memory management on userland and we use swap(ex, zram) heavily to maximize memory efficiency so workingset includes swap as well as RSS. On such system, if there are lots of shared anonymous pages, it's really hard to figure out exactly how many each process consumes memory(ie, rss + wap) if the system has lots of shared anonymous memory(e.g, android). This patch introduces SwapPss field on /proc/<pid>/smaps so we can get more exact workingset size per process. Bongkyu tested it. Result is below. 1. 50M used swap SwapTotal: 461976 kB SwapFree: 411192 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 48236 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 141184 2. 240M used swap SwapTotal: 461976 kB SwapFree: 216808 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 230315 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 1387744 [akpm@linux-foundation.org: simplify kunmap_atomic() call] Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Bongkyu Kim <bongkyu.kim@lge.com> Tested-by: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08memtest: remove unused header filesVladimir Murzin1-5/+0
memtest does not require these headers to be included. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Leon Romanovsky <leon@leon.nu> 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>
2015-09-08memtest: cleanup log messagesVladimir Murzin1-9/+5
- prefer pr_info(... to printk(KERN_INFO ... - use %pa for phys_addr_t - use cpu_to_be64 while printing pattern in reserve_bad_mem() Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Leon Romanovsky <leon@leon.nu> 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>
2015-09-08memtest: use kstrtouint instead of simple_strtoulVladimir Murzin1-3/+5
Since simple_strtoul is obsolete and memtest_pattern is type of int, use kstrtouint instead. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Leon Romanovsky <leon@leon.nu> 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>
2015-09-08mm/memblock.c: WARN_ON when flags differs from overlap regionWei Yang1-0/+1
Each memblock_region has flags to indicates the type of this range. For the overlap case, memblock_add_range() inserts the lower part and leave the upper part as indicated in the overlapped region. If the flags of the new range differs from the overlapped region, the information recorded is not correct. This patch adds a WARN_ON when the flags of the new range differs from the overlapped region. Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>