- 06 Feb, 2015 1 commit
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Kees Cook authored
commit d69911a6 upstream. Commit e6023367 ("x86, kaslr: Prevent .bss from overlaping initrd") added Perl to the required build environment. This reimplements in shell the Perl script used to find the size of the kernel with bss and brk added. Signed-off-by:
Kees Cook <keescook@chromium.org> Reported-by:
Rob Landley <rob@landley.net> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 30 Jan, 2015 39 commits
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Greg Kroah-Hartman authored
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NeilBrown authored
commit 108cef3a upstream. It is critical that fetch_block() and handle_stripe_dirtying() are consistent in their analysis of what needs to be loaded. Otherwise raid5 can wait forever for a block that won't be loaded. Currently when writing to a RAID5 that is resyncing, to a location beyond the resync offset, handle_stripe_dirtying chooses a reconstruct-write cycle, but fetch_block() assumes a read-modify-write, and a lockup can happen. So treat that case just like RAID6, just as we do in handle_stripe_dirtying. RAID6 always does reconstruct-write. This bug was introduced when the behaviour of handle_stripe_dirtying was changed in 3.7, so the patch is suitable for any kernel since, though it will need careful merging for some versions. Cc: stable@vger.kernel.org (v3.7+) Fixes: a7854487Reported-by:
Henry Cai <henryplusplus@gmail.com> Signed-off-by:
NeilBrown <neilb@suse.de> Signed-off-by:
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Michal Hocko authored
commit 45f87de5 upstream. Commit 2457aec6 ("mm: non-atomically mark page accessed during page cache allocation where possible") has added a separate parameter for specifying gfp mask for radix tree allocations. Not only this is less than optimal from the API point of view because it is error prone, it is also buggy currently because grab_cache_page_write_begin is using GFP_KERNEL for radix tree and if fgp_flags doesn't contain FGP_NOFS (mostly controlled by fs by AOP_FLAG_NOFS flag) but the mapping_gfp_mask has __GFP_FS cleared then the radix tree allocation wouldn't obey the restriction and might recurse into filesystem and cause deadlocks. This is the case for most filesystems unfortunately because only ext4 and gfs2 are using AOP_FLAG_NOFS. Let's simply remove radix_gfp_mask parameter because the allocation context is same for both page cache and for the radix tree. Just make sure that the radix tree gets only the sane subset of the mask (e.g. do not pass __GFP_WRITE). Long term it is more preferable to convert remaining users of AOP_FLAG_NOFS to use mapping_gfp_mask instead and simplify this interface even further. Reported-by:
Dave Chinner <david@fromorbit.com> Signed-off-by:
Michal Hocko <mhocko@suse.cz> Signed-off-by:
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Mel Gorman authored
commit 4ffeaf35 upstream. The fair zone allocation policy round-robins allocations between zones within a node to avoid age inversion problems during reclaim. If the first allocation fails, the batch counts are reset and a second attempt made before entering the slow path. One assumption made with this scheme is that batches expire at roughly the same time and the resets each time are justified. This assumption does not hold when zones reach their low watermark as the batches will be consumed at uneven rates. Allocation failure due to watermark depletion result in additional zonelist scans for the reset and another watermark check before hitting the slowpath. On UMA, the benefit is negligible -- around 0.25%. On 4-socket NUMA machine it's variable due to the variability of measuring overhead with the vmstat changes. The system CPU overhead comparison looks like 3.16.0-rc3 3.16.0-rc3 3.16.0-rc3 vanilla vmstat-v5 lowercost-v5 User 746.94 774.56 802.00 System 65336.22 32847.27 40852.33 Elapsed 27553.52 27415.04 27368.46 However it is worth noting that the overall benchmark still completed faster and intuitively it makes sense to take as few passes as possible through the zonelists. Signed-off-by:
Mel Gorman <mgorman@suse.de> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Mel Gorman authored
commit f7b5d647 upstream. The purpose of numa_zonelist_order=zone is to preserve lower zones for use with 32-bit devices. If locality is preferred then the numa_zonelist_order=node policy should be used. Unfortunately, the fair zone allocation policy overrides this by skipping zones on remote nodes until the lower one is found. While this makes sense from a page aging and performance perspective, it breaks the expected zonelist policy. This patch restores the expected behaviour for zone-list ordering. Signed-off-by:
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Mel Gorman authored
commit bb0b6dff upstream. When kswapd is awake reclaiming, the per-cpu stat thresholds are lowered to get more accurate counts to avoid breaching watermarks. This threshold update iterates over all possible CPUs which is unnecessary. Only online CPUs need to be updated. If a new CPU is onlined, refresh_zone_stat_thresholds() will set the thresholds correctly. Signed-off-by:
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Mel Gorman authored
commit 0d5d823a upstream. zone->pages_scanned is a write-intensive cache line during page reclaim and it's also updated during page free. Move the counter into vmstat to take advantage of the per-cpu updates and do not update it in the free paths unless necessary. On a small UMA machine running tiobench the difference is marginal. On a 4-node machine the overhead is more noticable. Note that automatic NUMA balancing was disabled for this test as otherwise the system CPU overhead is unpredictable. 3.16.0-rc3 3.16.0-rc3 3.16.0-rc3 vanillarearrange-v5 vmstat-v5 User 746.94 759.78 774.56 System 65336.22 58350.98 32847.27 Elapsed 27553.52 27282.02 27415.04 Note that the overhead reduction will vary depending on where exactly pages are allocated and freed. Signed-off-by:
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Mel Gorman authored
commit 3484b2de upstream. The arrangement of struct zone has changed over time and now it has reached the point where there is some inappropriate sharing going on. On x86-64 for example o The zone->node field is shared with the zone lock and zone->node is accessed frequently from the page allocator due to the fair zone allocation policy. o span_seqlock is almost never used by shares a line with free_area o Some zone statistics share a cache line with the LRU lock so reclaim-intensive and allocator-intensive workloads can bounce the cache line on a stat update This patch rearranges struct zone to put read-only and read-mostly fields together and then splits the page allocator intensive fields, the zone statistics and the page reclaim intensive fields into their own cache lines. Note that the type of lowmem_reserve changes due to the watermark calculations being signed and avoiding a signed/unsigned conversion there. On the test configuration I used the overall size of struct zone shrunk by one cache line. On smaller machines, this is not likely to be noticable. However, on a 4-node NUMA machine running tiobench the system CPU overhead is reduced by this patch. 3.16.0-rc3 3.16.0-rc3 vanillarearrange-v5r9 User 746.94 759.78 System 65336.22 58350.98 Elapsed 27553.52 27282.02 Signed-off-by:
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Mel Gorman authored
commit 24b7e581 upstream. This was formerly the series "Improve sequential read throughput" which noted some major differences in performance of tiobench since 3.0. While there are a number of factors, two that dominated were the introduction of the fair zone allocation policy and changes to CFQ. The behaviour of fair zone allocation policy makes more sense than tiobench as a benchmark and CFQ defaults were not changed due to insufficient benchmarking. This series is what's left. It's one functional fix to the fair zone allocation policy when used on NUMA machines and a reduction of overhead in general. tiobench was used for the comparison despite its flaws as an IO benchmark as in this case we are primarily interested in the overhead of page allocator and page reclaim activity. On UMA, it makes little difference to overhead 3.16.0-rc3 3.16.0-rc3 vanilla lowercost-v5 User 383.61 386.77 System 403.83 401.74 Elapsed 5411.50 5413.11 On a 4-socket NUMA machine it's a bit more noticable 3.16.0-rc3 3.16.0-rc3 vanilla lowercost-v5 User 746.94 802.00 System 65336.22 40852.33 Elapsed 27553.52 27368.46 This patch (of 6): The LRU insertion and activate tracepoints take PFN as a parameter forcing the overhead to the caller. Move the overhead to the tracepoint fast-assign method to ensure the cost is only incurred when the tracepoint is active. Signed-off-by:
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Jerome Marchand authored
commit 2ab051e1 upstream. When memory cgoups are enabled, the code that decides to force to scan anonymous pages in get_scan_count() compares global values (free, high_watermark) to a value that is restricted to a memory cgroup (file). It make the code over-eager to force anon scan. For instance, it will force anon scan when scanning a memcg that is mainly populated by anonymous page, even when there is plenty of file pages to get rid of in others memcgs, even when swappiness == 0. It breaks user's expectation about swappiness and hurts performance. This patch makes sure that forced anon scan only happens when there not enough file pages for the all zone, not just in one random memcg. [hannes@cmpxchg.org: cleanups] Signed-off-by:
Jerome Marchand <jmarchan@redhat.com> Acked-by:
Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by:
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Joonsoo Kim authored
commit 474750ab upstream. Richard Yao reported a month ago that his system have a trouble with vmap_area_lock contention during performance analysis by /proc/meminfo. Andrew asked why his analysis checks /proc/meminfo stressfully, but he didn't answer it. https://lkml.org/lkml/2014/4/10/416 Although I'm not sure that this is right usage or not, there is a solution reducing vmap_area_lock contention with no side-effect. That is just to use rcu list iterator in get_vmalloc_info(). rcu can be used in this function because all RCU protocol is already respected by writers, since Nick Piggin commit db64fe02 ("mm: rewrite vmap layer") back in linux-2.6.28 Specifically : insertions use list_add_rcu(), deletions use list_del_rcu() and kfree_rcu(). Note the rb tree is not used from rcu reader (it would not be safe), only the vmap_area_list has full RCU protection. Note that __purge_vmap_area_lazy() already uses this rcu protection. rcu_read_lock(); list_for_each_entry_rcu(va, &vmap_area_list, list) { if (va->flags & VM_LAZY_FREE) { if (va->va_start < *start) *start = va->va_start; if (va->va_end > *end) *end = va->va_end; nr += (va->va_end - va->va_start) >> PAGE_SHIFT; list_add_tail(&va->purge_list, &valist); va->flags |= VM_LAZY_FREEING; va->flags &= ~VM_LAZY_FREE; } } rcu_read_unlock(); Peter: : While rcu list traversal over the vmap_area_list is safe, this may : arrive at different results than the spinlocked version. The rcu list : traversal version will not be a 'snapshot' of a single, valid instant : of the entire vmap_area_list, but rather a potential amalgam of : different list states. Joonsoo: : Yes, you are right, but I don't think that we should be strict here. : Meminfo is already not a 'snapshot' at specific time. While we try to get : certain stats, the other stats can change. And, although we may arrive at : different results than the spinlocked version, the difference would not be : large and would not make serious side-effect. [edumazet@google.com: add more commit description] Signed-off-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-by:
Richard Yao <ryao@gentoo.org> Acked-by:
Eric Dumazet <edumazet@google.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Zhang Yanfei <zhangyanfei.yes@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by:
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Jerome Marchand authored
commit 21bda264 upstream. Commit 71e3aac0 ("thp: transparent hugepage core") adds copy_pte_range prototype to huge_mm.h. I'm not sure why (or if) this function have been used outside of memory.c, but it currently isn't. This patch makes copy_pte_range() static again. Signed-off-by:
David Rientjes <rientjes@google.com> Signed-off-by:
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David Rientjes authored
commit 14a4e214 upstream. Commit 9f1b868a ("mm: thp: khugepaged: add policy for finding target node") improved the previous khugepaged logic which allocated a transparent hugepages from the node of the first page being collapsed. However, it is still possible to collapse pages to remote memory which may suffer from additional access latency. With the current policy, it is possible that 255 pages (with PAGE_SHIFT == 12) will be collapsed remotely if the majority are allocated from that node. When zone_reclaim_mode is enabled, it means the VM should make every attempt to allocate locally to prevent NUMA performance degradation. In this case, we do not want to collapse hugepages to remote nodes that would suffer from increased access latency. Thus, when zone_reclaim_mode is enabled, only allow collapsing to nodes with RECLAIM_DISTANCE or less. There is no functional change for systems that disable zone_reclaim_mode. Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
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Hugh Dickins authored
commit c0d73261 upstream. Use ACCESS_ONCE() in handle_pte_fault() when getting the entry or orig_pte upon which all subsequent decisions and pte_same() tests will be made. I have no evidence that its lack is responsible for the mm/filemap.c:202 BUG_ON(page_mapped(page)) in __delete_from_page_cache() found by trinity, and I am not optimistic that it will fix it. But I have found no other explanation, and ACCESS_ONCE() here will surely not hurt. If gcc does re-access the pte before passing it down, then that would be disastrous for correct page fault handling, and certainly could explain the page_mapped() BUGs seen (concurrent fault causing page to be mapped in a second time on top of itself: mapcount 2 for a single pte). Signed-off-by:
Hugh Dickins <hughd@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
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Hugh Dickins authored
commit 66d2f4d2 upstream. Under shmem swapping load, I sometimes hit the VM_BUG_ON_PAGE(!PageLRU) in isolate_lru_pages() at mm/vmscan.c:1281! Commit 2457aec6 ("mm: non-atomically mark page accessed during page cache allocation where possible") looks like interrupted work-in-progress. mm/filemap.c's call to init_page_accessed() is fine, but not mm/shmem.c's - shmem_write_begin() is clearly wrong to use it after shmem_getpage(), when the page is always visible in radix_tree, and often already on LRU. Revert change to shmem_write_begin(), and use init_page_accessed() or mark_page_accessed() appropriately for SGP_WRITE in shmem_getpage_gfp(). SGP_WRITE also covers shmem_symlink(), which did not mark_page_accessed() before; but since many other filesystems use [__]page_symlink(), which did and does mark the page accessed, consider this as rectifying an oversight. Signed-off-by:
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Mel Gorman authored
commit 888cf2db upstream. If a page is marked for immediate reclaim then it is moved to the tail of the LRU list. This occurs when the system is under enough memory pressure for pages under writeback to reach the end of the LRU but we test for this using atomic operations on every writeback. This patch uses an optimistic non-atomic test first. It'll miss some pages in rare cases but the consequences are not severe enough to warrant such a penalty. While the function does not dominate profiles during a simple dd test the cost of it is reduced. 73048 0.7428 vmlinux-3.15.0-rc5-mmotm-20140513 end_page_writeback 23740 0.2409 vmlinux-3.15.0-rc5-lessatomic end_page_writeback Signed-off-by:
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Mel Gorman authored
commit 2457aec6 upstream. aops->write_begin may allocate a new page and make it visible only to have mark_page_accessed called almost immediately after. Once the page is visible the atomic operations are necessary which is noticable overhead when writing to an in-memory filesystem like tmpfs but should also be noticable with fast storage. The objective of the patch is to initialse the accessed information with non-atomic operations before the page is visible. The bulk of filesystems directly or indirectly use grab_cache_page_write_begin or find_or_create_page for the initial allocation of a page cache page. This patch adds an init_page_accessed() helper which behaves like the first call to mark_page_accessed() but may called before the page is visible and can be done non-atomically. The primary APIs of concern in this care are the following and are used by most filesystems. find_get_page find_lock_page find_or_create_page grab_cache_page_nowait grab_cache_page_write_begin All of them are very similar in detail to the patch creates a core helper pagecache_get_page() which takes a flags parameter that affects its behavior such as whether the page should be marked accessed or not. Then old API is preserved but is basically a thin wrapper around this core function. Each of the filesystems are then updated to avoid calling mark_page_accessed when it is known that the VM interfaces have already done the job. There is a slight snag in that the timing of the mark_page_accessed() has now changed so in rare cases it's possible a page gets to the end of the LRU as PageReferenced where as previously it might have been repromoted. This is expected to be rare but it's worth the filesystem people thinking about it in case they see a problem with the timing change. It is also the case that some filesystems may be marking pages accessed that previously did not but it makes sense that filesystems have consistent behaviour in this regard. The test case used to evaulate this is a simple dd of a large file done multiple times with the file deleted on each iterations. The size of the file is 1/10th physical memory to avoid dirty page balancing. In the async case it will be possible that the workload completes without even hitting the disk and will have variable results but highlight the impact of mark_page_accessed for async IO. The sync results are expected to be more stable. The exception is tmpfs where the normal case is for the "IO" to not hit the disk. The test machine was single socket and UMA to avoid any scheduling or NUMA artifacts. Throughput and wall times are presented for sync IO, only wall times are shown for async as the granularity reported by dd and the variability is unsuitable for comparison. As async results were variable do to writback timings, I'm only reporting the maximum figures. The sync results were stable enough to make the mean and stddev uninteresting. The performance results are reported based on a run with no profiling. Profile data is based on a separate run with oprofile running. async dd 3.15.0-rc3 3.15.0-rc3 vanilla accessed-v2 ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%) tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%) btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%) ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%) xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%) The XFS figure is a bit strange as it managed to avoid a worst case by sheer luck but the average figures looked reasonable. samples percentage ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed [akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer] Signed-off-by:
Prabhakar Lad <prabhakar.csengg@gmail.com> Signed-off-by:
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Mel Gorman authored
commit e7470ee8 upstream. Discarding buffers uses a bunch of atomic operations when discarding buffers because ...... I can't think of a reason. Use a cmpxchg loop to clear all the necessary flags. In most (all?) cases this will be a single atomic operations. [akpm@linux-foundation.org: move BUFFER_FLAGS_DISCARD into the .c file] Signed-off-by:
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Mel Gorman authored
commit 6fb81a17 upstream. When adding pages to the LRU we clear the active bit unconditionally. As the page could be reachable from other paths we cannot use unlocked operations without risk of corruption such as a parallel mark_page_accessed. This patch tests if is necessary to clear the active flag before using an atomic operation. This potentially opens a tiny race when PageActive is checked as mark_page_accessed could be called after PageActive was checked. The race already exists but this patch changes it slightly. The consequence is that that the page may be promoted to the active list that might have been left on the inactive list before the patch. It's too tiny a race and too marginal a consequence to always use atomic operations for. Signed-off-by:
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Mel Gorman authored
commit e3741b50 upstream. There should be no references to it any more and a parallel mark should not be reordered against us. Use non-locked varient to clear page active. Signed-off-by:
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Mel Gorman authored
commit 07a42788 upstream. shmem_getpage_gfp uses an atomic operation to set the SwapBacked field before it's even added to the LRU or visible. This is unnecessary as what could it possible race against? Use an unlocked variant. Signed-off-by:
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Mel Gorman authored
commit cfc47a28 upstream. get_pageblock_migratetype() is called during free with IRQs disabled. This is unnecessary and disables IRQs for longer than necessary. Signed-off-by:
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Mel Gorman authored
commit b745bc85 upstream. cold is a bool, make it one. Make the likely case the "if" part of the block instead of the else as according to the optimisation manual this is preferred. Signed-off-by:
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Mel Gorman authored
commit dc4b0caf upstream. In the free path we calculate page_to_pfn multiple times. Reduce that. Signed-off-by:
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Mel Gorman authored
commit 7aeb09f9 upstream. X86 prefers the use of unsigned types for iterators and there is a tendency to mix whether a signed or unsigned type if used for page order. This converts a number of sites in mm/page_alloc.c to use unsigned int for order where possible. Signed-off-by:
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Mel Gorman authored
commit 5dab2911 upstream. ALLOC_NO_WATERMARK is set in a few cases. Always by kswapd, always for __GFP_MEMALLOC, sometimes for swap-over-nfs, tasks etc. Each of these cases are relatively rare events but the ALLOC_NO_WATERMARK check is an unlikely branch in the fast path. This patch moves the check out of the fast path and after it has been determined that the watermarks have not been met. This helps the common fast path at the cost of making the slow path slower and hitting kswapd with a performance cost. It's a reasonable tradeoff. Signed-off-by:
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Mel Gorman authored
commit a6e21b14 upstream. Currently it's calculated once per zone in the zonelist. Signed-off-by:
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Mel Gorman authored
commit d34c5fa0 upstream. A node/zone index is used to check if pages are compatible for merging but this happens unconditionally even if the buddy page is not free. Defer the calculation as long as possible. Ideally we would check the zone boundary but nodes can overlap. Signed-off-by:
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Mel Gorman authored
commit d8846374 upstream. There is no need to calculate zone_idx(preferred_zone) multiple times or use the pgdat to figure it out. Signed-off-by:
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Mel Gorman authored
commit 664eedde upstream. If cpusets are not in use then we still check a global variable on every page allocation. Use jump labels to avoid the overhead. Signed-off-by:
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Mel Gorman authored
commit ea5e9539 upstream. This patch exposes the jump_label reference count in preparation for the next patch. cpusets cares about both the jump_label being enabled and how many users of the cpusets there currently are. Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Mel Gorman authored
commit 800a1e75 upstream. If a zone cannot be used for a dirty page then it gets marked "full" which is cached in the zlc and later potentially skipped by allocation requests that have nothing to do with dirty zones. Signed-off-by:
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Mel Gorman authored
commit 65bb3719 upstream. The zlc is used on NUMA machines to quickly skip over zones that are full. However it is always updated, even for the first zone scanned when the zlc might not even be active. As it's a write to a bitmap that potentially bounces cache line it's deceptively expensive and most machines will not care. Only update the zlc if it was active. Signed-off-by:
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Jianyu Zhan authored
commit 2329d375 upstream. In mm/swap.c, __lru_cache_add() is exported, but actually there are no users outside this file. This patch unexports __lru_cache_add(), and makes it static. It also exports lru_cache_add_file(), as it is use by cifs and fuse, which can loaded as modules. Signed-off-by:
Jianyu Zhan <nasa4836@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by:
Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by:
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Sjoerd Simons authored
[Not needed in newer kernels due to refactoring fixing this issue.] With 3.14.29 (and older kernels) some of my I.mx6 Sabrelite boards were crashing with the following oops: sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper sdhci-esdhc-imx 2198000.usdhc: could not get ultra high speed state, work on normal mode mmc0: no vqmmc regulator found mmc0: SDHCI controller on 2198000.usdhc [2198000.usdhc] using ADMA Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.29 #1 task: c08a7120 ti: c089c000 task.ti: c089c000 PC is at wake_up_process+0x8/0x40 LR is at sdhci_irq+0x748/0x9c4 Full boot log can be found at: http://storage.kernelci.org/stable/v3.14.29/arm-multi_v7_defconfig/lab-collabora/boot-imx6q-sabrelite.html This happens if the sdhci interrupt status contains SDHCI_INT_CARD_INT, while the sdio irq was never setup. This patch fixes that in a minimal way by checking if the sdio irq was setup. In more recent kernels this bug went away due to refactoring done by Russel King. So an alternative (potentially better?) fix for this patch is to cherrypick the following patches from a recent kernel: 18258f72 - genirq: Provide synchronize_hardirq() bf3b5ec6 - mmc: sdio_irq: rework sdio irq handling 41005003 - mmc: sdhci: clean up interrupt handling 781e989c - mmc: sdhci: convert to new SDIO IRQ handling Signed-off-by:
Sjoerd Simons <sjoerd.simons@collabora.co.uk> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tyler Baker <tyler.baker@linaro.org> Signed-off-by:
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Francesco Ruggeri authored
commit c4dc3046 upstream. Commit f95499c3 ("n_tty: Don't wait for buffer work in read() loop") introduces a race window where a pty master can be signalled that the pty slave was closed before all the data that the slave wrote is delivered. Commit f8747d4a ("tty: Fix pty master read() after slave closes") fixed the problem in case of n_tty_read, but the problem still exists for n_tty_poll. This can be seen by running 'for ((i=0; i<100;i++));do ./test.py ;done' where test.py is: import os, select, pty (pid, pty_fd) = pty.fork() if pid == 0: os.write(1, 'This string should be received by parent') else: poller = select.epoll() poller.register( pty_fd, select.EPOLLIN ) ready = poller.poll( 1 * 1000 ) for fd, events in ready: if not events & select.EPOLLIN: print 'missed POLLIN event' else: print os.read(fd, 100) poller.close() The string from the slave is missed several times. This patch takes the same approach as the fix for read and special cases this condition for poll. Tested on 3.16. Signed-off-by:
Francesco Ruggeri <fruggeri@arista.com> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by:
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Dmitry Torokhov authored
commit 7c4f5607 upstream. The 'max' size passed into the function is measured in number of bits (KEY_MAX, LED_MAX, etc) so we need to convert it accordingly before trying to copy the data out, otherwise we will try copying too much and end up with up with a page fault. Reported-by:
Pavel Machek <pavel@ucw.cz> Reviewed-by:
David Herrmann <dh.herrmann@gmail.com> Signed-off-by:
Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by:
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Vineet Gupta authored
commit ba25915f upstream. Fixes: ec7ac6af (ARC: switch to generic ENTRY/END assembler annotations) Reported-by:
Anton Kolesov <akolesov@synopsys.com> Signed-off-by:
Vineet Gupta <vgupta@synopsys.com> Signed-off-by:
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Vineet Gupta authored
commit 64ee9f32 upstream. Commit 93ea02bb ("arch: Clean up asm/barrier.h implementations") wired generic barrier.h for ARC, but failed to delete the existing file. In 3.15, due to rcupdate.h updates, this causes a build breakage on ARC: CC arch/arc/kernel/asm-offsets.s In file included from include/linux/sched.h:45:0, from arch/arc/kernel/asm-offsets.c:9: include/linux/rculist.h: In function __list_add_rcu: include/linux/rculist.h:54:2: error: implicit declaration of function smp_store_release [-Werror=implicit-function-declaration] rcu_assign_pointer(list_next_rcu(prev), new); ^ Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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