- 30 5月, 2012 40 次提交
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由 Hugh Dickins 提交于
It's quite easy for tmpfs to scan the radix_tree to support llseek's new SEEK_DATA and SEEK_HOLE options: so add them while the minutiae are still on my mind (in particular, the !PageUptodate-ness of pages fallocated but still unwritten). But I don't know who actually uses SEEK_DATA or SEEK_HOLE, and whether it would be of any use to them on tmpfs. This code adds 92 lines and 752 bytes on x86_64 - is that bloat or worthwhile? [akpm@linux-foundation.org: fix warning with CONFIG_TMPFS=n] Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Josef Bacik <josef@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Jeff liu <jeff.liu@oracle.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
As it stands, a large fallocate() on tmpfs is liable to fill memory with pages, freed on failure except when they run into swap, at which point they become fixed into the file despite the failure. That feels quite wrong, to be consuming resources precisely when they're in short supply. Go the other way instead: shmem_fallocate() indicate the range it has fallocated to shmem_writepage(), keeping count of pages it's allocating; shmem_writepage() reactivate instead of swapping out pages fallocated by this syscall (but happily swap out those from earlier occasions), keeping count; shmem_fallocate() compare counts and give up once the reactivated pages have started to coming back to writepage (approximately: some zones would in fact recycle faster than others). This is a little unusual, but works well: although we could consider the failure to swap as a bug, and fix it later with SWAP_MAP_FALLOC handling added in swapfile.c and memcontrol.c, I doubt that we shall ever want to. (If there's no swap, an over-large fallocate() on tmpfs is limited in the same way as writing: stopped by rlimit, or by tmpfs mount size if that was set sensibly, or by __vm_enough_memory() heuristics if OVERCOMMIT_GUESS or OVERCOMMIT_NEVER. If OVERCOMMIT_ALWAYS, then it is liable to OOM-kill others as writing would, but stops and frees if interrupted.) Now that everything is freed on failure, we can then skip updating ctime. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
In the previous episode, we left the already-fallocated pages attached to the file when shmem_fallocate() fails part way through. Now try to do better, by extending the earlier optimization of !Uptodate pages (then always under page lock) to !Uptodate pages (outside of page lock), representing fallocated pages. And don't waste time clearing them at the time of fallocate(), leave that until later if necessary. Adapt shmem_truncate_range() to shmem_undo_range(), so that a failing fallocate can recognize and remove precisely those !Uptodate allocations which it added (and were not independently allocated by racing tasks). But unless we start playing with swapfile.c and memcontrol.c too, once one of our fallocated pages reaches shmem_writepage(), we do then have to instantiate it as an ordinarily allocated page, before swapping out. This is unsatisfactory, but improved in the next episode. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
The systemd plumbers expressed a wish that tmpfs support preallocation. Cong Wang wrote a patch, but several kernel guys expressed scepticism: https://lkml.org/lkml/2011/11/18/137 Christoph Hellwig: What for exactly? Please explain why preallocating on tmpfs would make any sense. Kay Sievers: To be able to safely use mmap(), regarding SIGBUS, on files on the /dev/shm filesystem. The glibc fallback loop for -ENOSYS [or -EOPNOTSUPP] on fallocate is just ugly. Hugh Dickins: If tmpfs is going to support fallocate(FALLOC_FL_PUNCH_HOLE), it would seem perverse to permit the deallocation but fail the allocation. Christoph Hellwig: Agreed. Now that we do have shmem_fallocate() for hole-punching, plumb in basic support for preallocation mode too. It's fairly straightforward (though quite a few details needed attention), except for when it fails part way through. What a pity that fallocate(2) was not specified to return the length allocated, permitting short fallocations! As it is, when it fails part way through, we ought to free what has just been allocated by this system call; but must be very sure not to free any allocated earlier, or any allocated by racing accesses (not all excluded by i_mutex). But we cannot distinguish them: so in this patch simply leak allocations on partial failure (they will be freed later if the file is removed). An attractive alternative approach would have been for fallocate() not to allocate pages at all, but note reservations by entries in the radix-tree. But that would give less assurance, and, critically, would be hard to fit with mem cgroups (who owns the reservations?): allocating pages lets fallocate() behave in just the same way as write(). Based-on-patch-by: NCong Wang <amwang@redhat.com> Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Remove vmtruncate_range(), and remove the truncate_range method from struct inode_operations: only tmpfs ever supported it, and tmpfs has now converted over to using the fallocate method of file_operations. Update Documentation accordingly, adding (setlease and) fallocate lines. And while we're in mm.h, remove duplicate declarations of shmem_lock() and shmem_file_setup(): everyone is now using the ones in shmem_fs.h. Based-on-patch-by: NCong Wang <amwang@redhat.com> Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Now tmpfs supports hole-punching via fallocate(), switch madvise_remove() to use do_fallocate() instead of vmtruncate_range(): which extends madvise(,,MADV_REMOVE) support from tmpfs to ext4, ocfs2 and xfs. There is one more user of vmtruncate_range() in our tree, staging/android's ashmem_shrink(): convert it to use do_fallocate() too (but if its unpinned areas are already unmapped - I don't know - then it would do better to use shmem_truncate_range() directly). Based-on-patch-by: NCong Wang <amwang@redhat.com> Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Ben Myers <bpm@sgi.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
tmpfs has supported hole-punching since 2.6.16, via madvise(,,MADV_REMOVE). But nowadays fallocate(,FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE,,) is the agreed way to punch holes. So add shmem_fallocate() to support that, and tweak shmem_truncate_range() to support partial pages at both the beginning and end of range (never needed for madvise, which demands rounded addr and rounds up length). Based-on-patch-by: NCong Wang <amwang@redhat.com> Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Nick proposed years ago that tmpfs should avoid clearing its pages where write will overwrite them with new data, as ramfs has long done. But I messed it up and just got bad data. Tried again recently, it works fine. Here's time output for writing 4GiB 16 times on this Core i5 laptop: before: real 0m21.169s user 0m0.028s sys 0m21.057s real 0m21.382s user 0m0.016s sys 0m21.289s real 0m21.311s user 0m0.020s sys 0m21.217s after: real 0m18.273s user 0m0.032s sys 0m18.165s real 0m18.354s user 0m0.020s sys 0m18.265s real 0m18.440s user 0m0.032s sys 0m18.337s ramfs: real 0m16.860s user 0m0.028s sys 0m16.765s real 0m17.382s user 0m0.040s sys 0m17.273s real 0m17.133s user 0m0.044s sys 0m17.021s Yes, I have done perf reports, but they need more explanation than they deserve: in summary, clear_page vanishes, its cache loading shifts into copy_user_generic_unrolled; shmem_getpage_gfp goes down, and surprisingly mark_page_accessed goes way up - I think because they are respectively where the cache gets to be reloaded after being purged by clear or copy. Suggested-by: NNick Piggin <npiggin@gmail.com> Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Let tmpfs into the NOSEC optimization (avoiding file_remove_suid() overhead on most common writes): set MS_NOSEC on its superblocks. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
The GMA500 GPU driver uses GEM shmem objects, but with a new twist: the backing RAM has to be below 4GB. Not a problem while the boards supported only 4GB: but now Intel's D2700MUD boards support 8GB, and their GMA3600 is managed by the GMA500 driver. shmem/tmpfs has never pretended to support hardware restrictions on the backing memory, but it might have appeared to do so before v3.1, and even now it works fine until a page is swapped out then back in. When read_cache_page_gfp() supplied a freshly allocated page for copy, that compensated for whatever choice might have been made by earlier swapin readahead; but swapoff was likely to destroy the illusion. We'd like to continue to support GMA500, so now add a new shmem_should_replace_page() check on the zone when about to move a page from swapcache to filecache (in swapin and swapoff cases), with shmem_replace_page() to allocate and substitute a suitable page (given gma500/gem.c's mapping_set_gfp_mask GFP_KERNEL | __GFP_DMA32). This does involve a minor extension to mem_cgroup_replace_page_cache() (the page may or may not have already been charged); and I've removed a comment and call to mem_cgroup_uncharge_cache_page(), which in fact is always a no-op while PageSwapCache. Also removed optimization of an unlikely path in shmem_getpage_gfp(), now that we need to check PageSwapCache more carefully (a racing caller might already have made the copy). And at one point shmem_unuse_inode() needs to use the hitherto private page_swapcount(), to guard against racing with inode eviction. It would make sense to extend shmem_should_replace_page(), to cover cpuset and NUMA mempolicy restrictions too, but set that aside for now: needs a cleanup of shmem mempolicy handling, and more testing, and ought to handle swap faults in do_swap_page() as well as shmem. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Stephane Marchesin <marcheu@chromium.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Rob Clark <rob.clark@linaro.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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When MIGRATE_UNMOVABLE pages are freed from MIGRATE_UNMOVABLE type pageblock (and some MIGRATE_MOVABLE pages are left in it) waiting until an allocation takes ownership of the block may take too long. The type of the pageblock remains unchanged so the pageblock cannot be used as a migration target during compaction. Fix it by: * Adding enum compact_mode (COMPACT_ASYNC_[MOVABLE,UNMOVABLE], and COMPACT_SYNC) and then converting sync field in struct compact_control to use it. * Adding nr_pageblocks_skipped field to struct compact_control and tracking how many destination pageblocks were of MIGRATE_UNMOVABLE type. If COMPACT_ASYNC_MOVABLE mode compaction ran fully in try_to_compact_pages() (COMPACT_COMPLETE) it implies that there is not a suitable page for allocation. In this case then check how if there were enough MIGRATE_UNMOVABLE pageblocks to try a second pass in COMPACT_ASYNC_UNMOVABLE mode. * Scanning the MIGRATE_UNMOVABLE pageblocks (during COMPACT_SYNC and COMPACT_ASYNC_UNMOVABLE compaction modes) and building a count based on finding PageBuddy pages, page_count(page) == 0 or PageLRU pages. If all pages within the MIGRATE_UNMOVABLE pageblock are in one of those three sets change the whole pageblock type to MIGRATE_MOVABLE. My particular test case (on a ARM EXYNOS4 device with 512 MiB, which means 131072 standard 4KiB pages in 'Normal' zone) is to: - allocate 120000 pages for kernel's usage - free every second page (60000 pages) of memory just allocated - allocate and use 60000 pages from user space - free remaining 60000 pages of kernel memory (now we have fragmented memory occupied mostly by user space pages) - try to allocate 100 order-9 (2048 KiB) pages for kernel's usage The results: - with compaction disabled I get 11 successful allocations - with compaction enabled - 14 successful allocations - with this patch I'm able to get all 100 successful allocations NOTE: If we can make kswapd aware of order-0 request during compaction, we can enhance kswapd with changing mode to COMPACT_ASYNC_FULL (COMPACT_ASYNC_MOVABLE + COMPACT_ASYNC_UNMOVABLE). Please see the following thread: http://marc.info/?l=linux-mm&m=133552069417068&w=2 [minchan@kernel.org: minor cleanups] Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
alloc_bootmem_section() derives allocation area constraints from the specified sparsemem section. This is a bit specific for a generic memory allocator like bootmem, though, so move it over to sparsemem. As __alloc_bootmem_node_nopanic() already retries failed allocations with relaxed area constraints, the fallback code in sparsemem.c can be removed and the code becomes a bit more compact overall. [akpm@linux-foundation.org: fix build] Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Pass down the node descriptor instead of the more specific bootmem node descriptor down the call stack, like nobootmem does, when there is no good reason for the two to be different. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
While the panicking node-specific allocation function tries to satisfy node+goal, goal, node, anywhere, the non-panicking function still does node+goal, goal, anywhere. Make it simpler: define the panicking version in terms of the non-panicking one, like the node-agnostic interface, so they always behave the same way apart from how to deal with allocation failure. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NYinghai Lu <yinghai@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
__alloc_bootmem_node and __alloc_bootmem_low_node documentation claims the functions panic on allocation failure. Do it. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NYinghai Lu <yinghai@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
While the panicking node-specific allocation function tries to satisfy node+goal, goal, node, anywhere, the non-panicking function still does node+goal, goal, anywhere. Make it simpler: define the panicking version in terms of the non-panicking one, like the node-agnostic interface, so they always behave the same way apart from how to deal with allocation failure. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Match the nobootmem version of __alloc_bootmem_node. Try to satisfy both the node and the goal, then just the goal, then just the node, then allocate anywhere before panicking. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Matching the desired goal to the right node is one thing, dropping the goal when it can not be satisfied is another. Split this into separate functions so that subsequent patches can use the node-finding but drop and handle the goal fallback on their own terms. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Callsites need to provide a bootmem_data_t *, make the naming more descriptive. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
When bootmem releases an unaligned BITS_PER_LONG pages chunk of memory to the page allocator, it checks the bitmap if there are still unreserved pages in the chunk (set bits), but also if the offset in the chunk indicates BITS_PER_LONG loop iterations already. But since the consulted bitmap is only a one-word-excerpt of the full per-node bitmap, there can not be more than BITS_PER_LONG bits set in it. The additional offset check is unnecessary. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Gavin Shan 提交于
When bootmem releases an unaligned chunk of memory at the beginning of a node to the page allocator, it iterates from that unaligned PFN but checks an aligned word of the page bitmap. The checked bits do not correspond to the PFNs and, as a result, reserved pages can be freed. Properly shift the bitmap word so that the lowest bit corresponds to the starting PFN before entering the freeing loop. This bug has been around since commit 41546c17 ("bootmem: clean up free_all_bootmem_core") (2.6.27) without known reports. Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrew Morton 提交于
This has always been broken: one version takes an unsigned int and the other version takes no arguments. This bug was hidden because one version of set_pageblock_order() was a macro which doesn't evaluate its argument. Simplify it all and remove pageblock_default_order() altogether. Reported-by: Nrajman mekaco <rajman.mekaco@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Bjorn Helgaas 提交于
Print physical address info in a style consistent with the %pR style used elsewhere in the kernel. For example: -Zone PFN ranges: +Zone ranges: - DMA32 0x00000010 -> 0x00100000 + DMA32 [mem 0x00010000-0xffffffff] - Normal 0x00100000 -> 0x01080000 + Normal [mem 0x100000000-0x107fffffff] Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Christopher Yeoh 提交于
Add a Kconfig option to allow people who don't want cross memory attach to not have it included in their build. Signed-off-by: NChris Yeoh <yeohc@au1.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
mm->page_table_lock is hotly contested for page fault tests and isn't necessary to do mem_cgroup_uncharge_page() in do_huge_pmd_wp_page(). Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ying Han 提交于
Andrew pointed out that the is_mlocked_vma() is misnamed. A function with name like that would expect bool return and no side-effects. Since it is called on the fault path for new page, rename it in this patch. Signed-off-by: NYing Han <yinghan@google.com> Reviewed-by: NRik van Riel <riel@redhat.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com> Reviewed-by: NMinchan Kim <minchan@kernel.org> [akpm@linux-foundation.org: s/mlock_vma_newpage/mlock_vma_newpage/, per Minchan] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
The rmap walker checking page table references has historically ignored references from VMAs that were not part of the memcg that was being reclaimed during memcg hard limit reclaim. When transitioning global reclaim to memcg hierarchy reclaim, I missed that bit and now references from outside a memcg are ignored even during global reclaim. Reverting back to traditional behaviour - count all references during global reclaim and only mind references of the memcg being reclaimed during limit reclaim would be one option. However, the more generic idea is to ignore references exactly then when they are outside the hierarchy that is currently under reclaim; because only then will their reclamation be of any use to help the pressure situation. It makes no sense to ignore references from a sibling memcg and then evict a page that will be immediately refaulted by that sibling which contributes to the same usage of the common ancestor under reclaim. The solution: make the rmap walker ignore references from VMAs that are not part of the hierarchy that is being reclaimed. Flat limit reclaim will stay the same, hierarchical limit reclaim will mind the references only to pages that the hierarchy owns. Global reclaim, since it reclaims from all memcgs, will be fixed to regard all references. [akpm@linux-foundation.org: name the args in the declaration] Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Reported-by: NKonstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: Konstantin Khlebnikov<khlebnikov@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NMichal Hocko <mhocko@suse.cz> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Library functions should not grab locks when the callsites can do it, even if the lock nests like the rcu read-side lock does. Push the rcu_read_lock() from css_is_ancestor() to its single user, mem_cgroup_same_or_subtree() in preparation for another user that may already hold the rcu read-side lock. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NMichal Hocko <mhocko@suse.cz> Acked-by: NLi Zefan <lizf@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrew Morton 提交于
s/from_nodes/from and s/to_nodes/to/. The "_nodes" is redundant - it duplicates the argument's type. Done in a fit of irritation over 80-col issues :( Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <mkosaki@redhat.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Larry Woodman 提交于
While running an application that moves tasks from one cpuset to another I noticed that it takes much longer and moves many more pages than expected. The reason for this is do_migrate_pages() does its best to preserve the relative node differential from the first node of the cpuset because the application may have been written with that in mind. If memory was interleaved on the nodes of the source cpuset by an application do_migrate_pages() will try its best to maintain that interleaving on the nodes of the destination cpuset. This means copying the memory from all source nodes to the destination nodes even if the source and destination nodes overlap. This is a problem for userspace NUMA placement tools. The amount of time spent doing extra memory moves cancels out some of the NUMA performance improvements. Furthermore, if the number of source and destination nodes are to maintain the previous interleaving layout anyway. This patch changes do_migrate_pages() to only preserve the relative layout inside the program if the number of NUMA nodes in the source and destination mask are the same. If the number is different, we do a much more efficient migration by not touching memory that is in an allowed node. This preserves the old behaviour for programs that want it, while allowing a userspace NUMA placement tool to use the new, faster migration. This improves performance in our tests by up to a factor of 7. Without this change migrating tasks from a cpuset containing nodes 0-7 to a cpuset containing nodes 3-4, we migrate from ALL the nodes even if they are in the both the source and destination nodesets: Migrating 7 to 4 Migrating 6 to 3 Migrating 5 to 4 Migrating 4 to 3 Migrating 1 to 4 Migrating 3 to 4 Migrating 0 to 3 Migrating 2 to 3 With this change we only migrate from nodes that are not in the destination nodesets: Migrating 7 to 4 Migrating 6 to 3 Migrating 5 to 4 Migrating 2 to 3 Migrating 1 to 4 Migrating 0 to 3 Yet if we move from a cpuset containing nodes 2,3,4 to a cpuset containing 3,4,5 we still do move everything so that we preserve the desired NUMA offsets: Migrating 4 to 5 Migrating 3 to 4 Migrating 2 to 3 As far as performance is concerned this simple patch improves the time it takes to move 14, 20 and 26 large tasks from a cpuset containing nodes 0-7 to a cpuset containing nodes 1 & 3 by up to a factor of 7. Here are the timings with and without the patch: BEFORE PATCH -- Move times: 59, 140, 651 seconds ============ Moving 14 tasks from nodes (0-7) to nodes (1,3) numad(8780) do_migrate_pages (mm=0xffff88081d414400 from_nodes=0xffff880818c81d28 to_nodes=0xffff880818c81ce8 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x7 dest=0x3 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x6 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x5 dest=0x3 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x4 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x2 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x1 dest=0x3 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d414400 source=0x0 dest=0x1 flags=0x4) (Above moves repeated for each of the 14 tasks...) PID 8890 moved to node(s) 1,3 in 59.2 seconds Moving 20 tasks from nodes (0-7) to nodes (1,4-5) numad(8780) do_migrate_pages (mm=0xffff88081d88c700 from_nodes=0xffff880818c81d28 to_nodes=0xffff880818c81ce8 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x7 dest=0x4 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x6 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x3 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x2 dest=0x5 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x1 dest=0x4 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d88c700 source=0x0 dest=0x1 flags=0x4) (Above moves repeated for each of the 20 tasks...) PID 8962 moved to node(s) 1,4-5 in 139.88 seconds Moving 26 tasks from nodes (0-7) to nodes (1-3,5) numad(8780) do_migrate_pages (mm=0xffff88081d5bc740 from_nodes=0xffff880818c81d28 to_nodes=0xffff880818c81ce8 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x7 dest=0x5 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x6 dest=0x3 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x5 dest=0x2 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x3 dest=0x5 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x2 dest=0x3 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x1 dest=0x2 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x0 dest=0x1 flags=0x4) numad(8780) migrate_to_node (mm=0xffff88081d5bc740 source=0x4 dest=0x1 flags=0x4) (Above moves repeated for each of the 26 tasks...) PID 9058 moved to node(s) 1-3,5 in 651.45 seconds AFTER PATCH -- Move times: 42, 56, 93 seconds =========== Moving 14 tasks from nodes (0-7) to nodes (5,7) numad(33209) do_migrate_pages (mm=0xffff88101d5ff140 from_nodes=0xffff88101e7b5d28 to_nodes=0xffff88101e7b5ce8 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x6 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x4 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x3 dest=0x7 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x2 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x1 dest=0x7 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d5ff140 source=0x0 dest=0x5 flags=0x4) (Above moves repeated for each of the 14 tasks...) PID 33221 moved to node(s) 5,7 in 41.67 seconds Moving 20 tasks from nodes (0-7) to nodes (1,3,5) numad(33209) do_migrate_pages (mm=0xffff88101d6c37c0 from_nodes=0xffff88101e7b5d28 to_nodes=0xffff88101e7b5ce8 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d6c37c0 source=0x7 dest=0x3 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d6c37c0 source=0x6 dest=0x1 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d6c37c0 source=0x4 dest=0x3 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d6c37c0 source=0x2 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d6c37c0 source=0x0 dest=0x1 flags=0x4) (Above moves repeated for each of the 20 tasks...) PID 33289 moved to node(s) 1,3,5 in 56.3 seconds Moving 26 tasks from nodes (0-7) to nodes (1,3,5,7) numad(33209) do_migrate_pages (mm=0xffff88101d924400 from_nodes=0xffff88101e7b5d28 to_nodes=0xffff88101e7b5ce8 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d924400 source=0x6 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d924400 source=0x4 dest=0x1 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d924400 source=0x2 dest=0x5 flags=0x4) numad(33209) migrate_to_node (mm=0xffff88101d924400 source=0x0 dest=0x1 flags=0x4) (Above moves repeated for each of the 26 tasks...) PID 33372 moved to node(s) 1,3,5,7 in 92.67 seconds [akpm@linux-foundation.org: clean up comment layout] Signed-off-by: NLarry Woodman <lwoodman@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
On COW, a new hugepage is allocated and charged to the memcg. If the system is oom or the charge to the memcg fails, however, the fault handler will return VM_FAULT_OOM which results in an oom kill. Instead, it's possible to fallback to splitting the hugepage so that the COW results only in an order-0 page being allocated and charged to the memcg which has a higher liklihood to succeed. This is expensive because the hugepage must be split in the page fault handler, but it is much better than unnecessarily oom killing a process. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Sasikantha babu 提交于
mm/vmstat.c: remove debug fs entries on failure of file creation and made extfrag_debug_root dentry local Remove debug fs files and directory on failure. Since no one is using "extfrag_debug_root" dentry outside of extfrag_debug_init(), make it local to the function. Signed-off-by: NSasikantha babu <sasikanth.v19@gmail.com> Acked-by: NDavid Rientjes <rientjes@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rajman Mekaco 提交于
The "if (mm)" check is not required in find_vma, as the kernel code calls find_vma only when it is absolutely sure that the mm_struct arg to it is non-NULL. Remove the if(mm) check and adding the a WARN_ONCE(!mm) for now. This will serve the purpose of mandating that the execution context(user-mode/kernel-mode) be known before find_vma is called. Also fixed 2 checkpatch.pl errors in the declaration of the rb_node and vma_tmp local variables. I was browsing through the internet and read a discussion at https://lkml.org/lkml/2012/3/27/342 which discusses removal of the validation check within find_vma. Since no-one responded, I decided to send this patch with Andrew's suggestions. [akpm@linux-foundation.org: add remove-me comment] Signed-off-by: NRajman Mekaco <rajman.mekaco@gmail.com> Cc: Kautuk Consul <consul.kautuk@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Thomas Meyer 提交于
The advantage of kcalloc is, that will prevent integer overflows which could result from the multiplication of number of elements and size and it is also a bit nicer to read. The semantic patch that makes this change is available in https://lkml.org/lkml/2011/11/25/107Signed-off-by: NThomas Meyer <thomas@m3y3r.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
There is little motiviation for reclaim_mode_t once RECLAIM_MODE_[A]SYNC and lumpy reclaim have been removed. This patch gets rid of reclaim_mode_t as well and improves the documentation about what reclaim/compaction is and when it is triggered. Signed-off-by: NMel Gorman <mgorman@suse.de> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: Ying Han <yinghan@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
This patch stops reclaim/compaction entering sync reclaim as this was only intended for lumpy reclaim and an oversight. Page migration has its own logic for stalling on writeback pages if necessary and memory compaction is already using it. Waiting on page writeback is bad for a number of reasons but the primary one is that waiting on writeback to a slow device like USB can take a considerable length of time. Page reclaim instead uses wait_iff_congested() to throttle if too many dirty pages are being scanned. Signed-off-by: NMel Gorman <mgorman@suse.de> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: Ying Han <yinghan@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
This series removes lumpy reclaim and some stalling logic that was unintentionally being used by memory compaction. The end result is that stalling on dirty pages during page reclaim now depends on wait_iff_congested(). Four kernels were compared 3.3.0 vanilla 3.4.0-rc2 vanilla 3.4.0-rc2 lumpyremove-v2 is patch one from this series 3.4.0-rc2 nosync-v2r3 is the full series Removing lumpy reclaim saves almost 900 bytes of text whereas the full series removes 1200 bytes. text data bss dec hex filename 67403754 1927944 2260992 10929311 a6c49f vmlinux-3.4.0-rc2-vanilla 6739479 1927944 2260992 10928415 a6c11f vmlinux-3.4.0-rc2-lumpyremove-v2 6739159 1927944 2260992 10928095 a6bfdf vmlinux-3.4.0-rc2-nosync-v2 There are behaviour changes in the series and so tests were run with monitoring of ftrace events. This disrupts results so the performance results are distorted but the new behaviour should be clearer. fs-mark running in a threaded configuration showed little of interest as it did not push reclaim aggressively FS-Mark Multi Threaded 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Files/s min 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Files/s mean 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Files/s stddev 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) Files/s max 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Overhead min 508667.00 ( 0.00%) 521350.00 (-2.49%) 544292.00 (-7.00%) 547168.00 (-7.57%) Overhead mean 551185.00 ( 0.00%) 652690.73 (-18.42%) 991208.40 (-79.83%) 570130.53 (-3.44%) Overhead stddev 18200.69 ( 0.00%) 331958.29 (-1723.88%) 1579579.43 (-8578.68%) 9576.81 (47.38%) Overhead max 576775.00 ( 0.00%) 1846634.00 (-220.17%) 6901055.00 (-1096.49%) 585675.00 (-1.54%) MMTests Statistics: duration Sys Time Running Test (seconds) 309.90 300.95 307.33 298.95 User+Sys Time Running Test (seconds) 319.32 309.67 315.69 307.51 Total Elapsed Time (seconds) 1187.85 1193.09 1191.98 1193.73 MMTests Statistics: vmstat Page Ins 80532 82212 81420 79480 Page Outs 111434984 111456240 111437376 111582628 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 44881 27889 27453 34843 Kswapd pages scanned 25841428 25860774 25861233 25843212 Kswapd pages reclaimed 25841393 25860741 25861199 25843179 Direct pages reclaimed 44881 27889 27453 34843 Kswapd efficiency 99% 99% 99% 99% Kswapd velocity 21754.791 21675.460 21696.029 21649.127 Direct efficiency 100% 100% 100% 100% Direct velocity 37.783 23.375 23.031 29.188 Percentage direct scans 0% 0% 0% 0% ftrace showed that there was no stalling on writeback or pages submitted for IO from reclaim context. postmark was similar and while it was more interesting, it also did not push reclaim heavily. POSTMARK 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Transactions per second: 16.00 ( 0.00%) 20.00 (25.00%) 18.00 (12.50%) 17.00 ( 6.25%) Data megabytes read per second: 18.80 ( 0.00%) 24.27 (29.10%) 22.26 (18.40%) 20.54 ( 9.26%) Data megabytes written per second: 35.83 ( 0.00%) 46.25 (29.08%) 42.42 (18.39%) 39.14 ( 9.24%) Files created alone per second: 28.00 ( 0.00%) 38.00 (35.71%) 34.00 (21.43%) 30.00 ( 7.14%) Files create/transact per second: 8.00 ( 0.00%) 10.00 (25.00%) 9.00 (12.50%) 8.00 ( 0.00%) Files deleted alone per second: 556.00 ( 0.00%) 1224.00 (120.14%) 3062.00 (450.72%) 6124.00 (1001.44%) Files delete/transact per second: 8.00 ( 0.00%) 10.00 (25.00%) 9.00 (12.50%) 8.00 ( 0.00%) MMTests Statistics: duration Sys Time Running Test (seconds) 113.34 107.99 109.73 108.72 User+Sys Time Running Test (seconds) 145.51 139.81 143.32 143.55 Total Elapsed Time (seconds) 1159.16 899.23 980.17 1062.27 MMTests Statistics: vmstat Page Ins 13710192 13729032 13727944 13760136 Page Outs 43071140 42987228 42733684 42931624 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 0 0 0 0 Kswapd pages scanned 9941613 9937443 9939085 9929154 Kswapd pages reclaimed 9940926 9936751 9938397 9928465 Direct pages reclaimed 0 0 0 0 Kswapd efficiency 99% 99% 99% 99% Kswapd velocity 8576.567 11051.058 10140.164 9347.109 Direct efficiency 100% 100% 100% 100% Direct velocity 0.000 0.000 0.000 0.000 It looks like here that the full series regresses performance but as ftrace showed no usage of wait_iff_congested() or sync reclaim I am assuming it's a disruption due to monitoring. Other data such as memory usage, page IO, swap IO all looked similar. Running a benchmark with a plain DD showed nothing very interesting. The full series stalled in wait_iff_congested() slightly less but stall times on vanilla kernels were marginal. Running a benchmark that hammered on file-backed mappings showed stalls due to congestion but not in sync writebacks MICRO 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 MMTests Statistics: duration Sys Time Running Test (seconds) 308.13 294.50 298.75 299.53 User+Sys Time Running Test (seconds) 330.45 316.28 318.93 320.79 Total Elapsed Time (seconds) 1814.90 1833.88 1821.14 1832.91 MMTests Statistics: vmstat Page Ins 108712 120708 97224 110344 Page Outs 155514576 156017404 155813676 156193256 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 2599253 1550480 2512822 2414760 Kswapd pages scanned 69742364 71150694 68839041 69692533 Kswapd pages reclaimed 34824488 34773341 34796602 34799396 Direct pages reclaimed 53693 94750 61792 75205 Kswapd efficiency 49% 48% 50% 49% Kswapd velocity 38427.662 38797.901 37799.972 38022.889 Direct efficiency 2% 6% 2% 3% Direct velocity 1432.174 845.464 1379.807 1317.446 Percentage direct scans 3% 2% 3% 3% Page writes by reclaim 0 0 0 0 Page writes file 0 0 0 0 Page writes anon 0 0 0 0 Page reclaim immediate 0 0 0 1218 Page rescued immediate 0 0 0 0 Slabs scanned 15360 16384 13312 16384 Direct inode steals 0 0 0 0 Kswapd inode steals 4340 4327 1630 4323 FTrace Reclaim Statistics: congestion_wait Direct number congest waited 0 0 0 0 Direct time congest waited 0ms 0ms 0ms 0ms Direct full congest waited 0 0 0 0 Direct number conditional waited 900 870 754 789 Direct time conditional waited 0ms 0ms 0ms 20ms Direct full conditional waited 0 0 0 0 KSwapd number congest waited 2106 2308 2116 1915 KSwapd time congest waited 139924ms 157832ms 125652ms 132516ms KSwapd full congest waited 1346 1530 1202 1278 KSwapd number conditional waited 12922 16320 10943 14670 KSwapd time conditional waited 0ms 0ms 0ms 0ms KSwapd full conditional waited 0 0 0 0 Reclaim statistics are not radically changed. The stall times in kswapd are massive but it is clear that it is due to calls to congestion_wait() and that is almost certainly the call in balance_pgdat(). Otherwise stalls due to dirty pages are non-existant. I ran a benchmark that stressed high-order allocation. This is very artifical load but was used in the past to evaluate lumpy reclaim and compaction. Generally I look at allocation success rates and latency figures. STRESS-HIGHALLOC 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Pass 1 81.00 ( 0.00%) 28.00 (-53.00%) 24.00 (-57.00%) 28.00 (-53.00%) Pass 2 82.00 ( 0.00%) 39.00 (-43.00%) 38.00 (-44.00%) 43.00 (-39.00%) while Rested 88.00 ( 0.00%) 87.00 (-1.00%) 88.00 ( 0.00%) 88.00 ( 0.00%) MMTests Statistics: duration Sys Time Running Test (seconds) 740.93 681.42 685.14 684.87 User+Sys Time Running Test (seconds) 2922.65 3269.52 3281.35 3279.44 Total Elapsed Time (seconds) 1161.73 1152.49 1159.55 1161.44 MMTests Statistics: vmstat Page Ins 4486020 2807256 2855944 2876244 Page Outs 7261600 7973688 7975320 7986120 Swap Ins 31694 0 0 0 Swap Outs 98179 0 0 0 Direct pages scanned 53494 57731 34406 113015 Kswapd pages scanned 6271173 1287481 1278174 1219095 Kswapd pages reclaimed 2029240 1281025 1260708 1201583 Direct pages reclaimed 1468 14564 16649 92456 Kswapd efficiency 32% 99% 98% 98% Kswapd velocity 5398.133 1117.130 1102.302 1049.641 Direct efficiency 2% 25% 48% 81% Direct velocity 46.047 50.092 29.672 97.306 Percentage direct scans 0% 4% 2% 8% Page writes by reclaim 1616049 0 0 0 Page writes file 1517870 0 0 0 Page writes anon 98179 0 0 0 Page reclaim immediate 103778 27339 9796 17831 Page rescued immediate 0 0 0 0 Slabs scanned 1096704 986112 980992 998400 Direct inode steals 223 215040 216736 247881 Kswapd inode steals 175331 61548 68444 63066 Kswapd skipped wait 21991 0 1 0 THP fault alloc 1 135 125 134 THP collapse alloc 393 311 228 236 THP splits 25 13 7 8 THP fault fallback 0 0 0 0 THP collapse fail 3 5 7 7 Compaction stalls 865 1270 1422 1518 Compaction success 370 401 353 383 Compaction failures 495 869 1069 1135 Compaction pages moved 870155 3828868 4036106 4423626 Compaction move failure 26429 23865 29742 27514 Success rates are completely hosed for 3.4-rc2 which is almost certainly due to commit fe2c2a10 ("vmscan: reclaim at order 0 when compaction is enabled"). I expected this would happen for kswapd and impair allocation success rates (https://lkml.org/lkml/2012/1/25/166) but I did not anticipate this much a difference: 80% less scanning, 37% less reclaim by kswapd In comparison, reclaim/compaction is not aggressive and gives up easily which is the intended behaviour. hugetlbfs uses __GFP_REPEAT and would be much more aggressive about reclaim/compaction than THP allocations are. The stress test above is allocating like neither THP or hugetlbfs but is much closer to THP. Mainline is now impaired in terms of high order allocation under heavy load although I do not know to what degree as I did not test with __GFP_REPEAT. Keep this in mind for bugs related to hugepage pool resizing, THP allocation and high order atomic allocation failures from network devices. In terms of congestion throttling, I see the following for this test FTrace Reclaim Statistics: congestion_wait Direct number congest waited 3 0 0 0 Direct time congest waited 0ms 0ms 0ms 0ms Direct full congest waited 0 0 0 0 Direct number conditional waited 957 512 1081 1075 Direct time conditional waited 0ms 0ms 0ms 0ms Direct full conditional waited 0 0 0 0 KSwapd number congest waited 36 4 3 5 KSwapd time congest waited 3148ms 400ms 300ms 500ms KSwapd full congest waited 30 4 3 5 KSwapd number conditional waited 88514 197 332 542 KSwapd time conditional waited 4980ms 0ms 0ms 0ms KSwapd full conditional waited 49 0 0 0 The "conditional waited" times are the most interesting as this is directly impacted by the number of dirty pages encountered during scan. As lumpy reclaim is no longer scanning contiguous ranges, it is finding fewer dirty pages. This brings wait times from about 5 seconds to 0. kswapd itself is still calling congestion_wait() so it'll still stall but it's a lot less. In terms of the type of IO we were doing, I see this FTrace Reclaim Statistics: mm_vmscan_writepage Direct writes anon sync 0 0 0 0 Direct writes anon async 0 0 0 0 Direct writes file sync 0 0 0 0 Direct writes file async 0 0 0 0 Direct writes mixed sync 0 0 0 0 Direct writes mixed async 0 0 0 0 KSwapd writes anon sync 0 0 0 0 KSwapd writes anon async 91682 0 0 0 KSwapd writes file sync 0 0 0 0 KSwapd writes file async 822629 0 0 0 KSwapd writes mixed sync 0 0 0 0 KSwapd writes mixed async 0 0 0 0 In 3.2, kswapd was doing a bunch of async writes of pages but reclaim/compaction was never reaching a point where it was doing sync IO. This does not guarantee that reclaim/compaction was not calling wait_on_page_writeback() but I would consider it unlikely. It indicates that merging patches 2 and 3 to stop reclaim/compaction calling wait_on_page_writeback() should be safe. This patch: Lumpy reclaim had a purpose but in the mind of some, it was to kick the system so hard it trashed. For others the purpose was to complicate vmscan.c. Over time it was giving softer shoes and a nicer attitude but memory compaction needs to step up and replace it so this patch sends lumpy reclaim to the farm. The tracepoint format changes for isolating LRU pages with this patch applied. Furthermore reclaim/compaction can no longer queue dirty pages in pageout() if the underlying BDI is congested. Lumpy reclaim used this logic and reclaim/compaction was using it in error. Signed-off-by: NMel Gorman <mgorman@suse.de> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: Ying Han <yinghan@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rik van Riel 提交于
The swap token code no longer fits in with the current VM model. It does not play well with cgroups or the better NUMA placement code in development, since we have only one swap token globally. It also has the potential to mess with scalability of the system, by increasing the number of non-reclaimable pages on the active and inactive anon LRU lists. Last but not least, the swap token code has been broken for a year without complaints, as reported by Konstantin Khlebnikov. This suggests we no longer have much use for it. The days of sub-1G memory systems with heavy use of swap are over. If we ever need thrashing reducing code in the future, we will have to implement something that does scale. Signed-off-by: NRik van Riel <riel@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Acked-by: NBob Picco <bpicco@meloft.net> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
The transparent hugepages feature is careful to not invoke the oom killer when a hugepage cannot be allocated. pte_alloc_one() failing in __do_huge_pmd_anonymous_page(), however, currently results in VM_FAULT_OOM which invokes the pagefault oom killer to kill a memory-hogging task. This is unnecessary since it's possible to drop the reference to the hugepage and fallback to allocating a small page. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
The "ret" variable is unnecessary in __do_huge_pmd_anonymous_page(), so remove it. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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