- 03 Sep, 2021 40 commits
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Suren Baghdasaryan authored
Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and cgroup_throttle_swaprate functions. This minimizes the memcg overhead in the pagefault and exit_mmap paths when memcgs are disabled using cgroup_disable=memory command-line option. This change results in ~2.1% overhead reduction when running PFT test [1] comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y, CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core ARM64 Android device. [1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite Link: https://lkml.kernel.org/r/20210713010934.299876-1-surenb@google.comSigned-off-by:Suren Baghdasaryan <surenb@google.com> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Reviewed-by:
Muchun Song <songmuchun@bytedance.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Alex Shi <alexs@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Hugh Dickins authored
drivers/gpu/drm/i915/gem/i915_gem_shmem.c contains a shmem_writeback() which calls shmem_writepage() from a shrinker: that usually works well enough; but if /sys/kernel/mm/transparent_hugepage/shmem_enabled has been set to "always" (intended to be usable) or "force" (forces huge everywhere for easy testing), shmem_writepage() is surprised to be called with a huge page, and crashes on the VM_BUG_ON_PAGE(PageCompound) (I did not find out where the crash happens when CONFIG_DEBUG_VM is off). LRU page reclaim always splits the shmem huge page first: I'd prefer not to demand that of i915, so check and split compound in shmem_writepage(). Patch history: when first sent last year http://lkml.kernel.org/r/alpine.LSU.2.11.2008301401390.5954@eggly.anvils https://lore.kernel.org/linux-mm/20200919042009.bomzxmrg7%25akpm@linux-foundation.org/ Matthew Wilcox noticed that tail pages were wrongly left clean. This version brackets the split with Set and Clear PageDirty as he suggested: which works very well, even if it falls short of our aspirations. And recently I realized that the crash is not limited to the testing option "force", but affects "always" too: which is more important to fix. Link: https://lkml.kernel.org/r/bac6158c-8b3d-4dca-cffc-4982f58d9794@google.com Fixes: 2d6692e6 ("drm/i915: Start writeback from the shrinker") Signed-off-by:
Hugh Dickins <hughd@google.com> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by:
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Hugh Dickins authored
4.18 commit 89fdcd26 ("mm: shmem: make stat.st_blksize return huge page size if THP is on") added is_huge_enabled() to decide st_blksize: if hugeness is to be defined per file, that will need to be replaced by shmem_is_huge(). This does give a different answer (No) for small files on a "huge=within_size" mount: but that can be considered a minor bugfix. And a different answer (No) for default files on a "huge=advise" mount: I'm reluctant to complicate it, just to reproduce the same debatable answer as before. Link: https://lkml.kernel.org/r/af7fb3f9-4415-9e8e-fdac-b1a5253ad21@google.comSigned-off-by:
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Hugh Dickins authored
Extend shmem_huge_enabled(vma) to shmem_is_huge(vma, inode, index), so that a consistent set of checks can be applied, even when the inode is accessed through read/write syscalls (with NULL vma) instead of mmaps (the index argument is seldom of interest, but required by mount option "huge=within_size"). Clean up and rearrange the checks a little. This then replaces the checks which shmem_fault() and shmem_getpage_gfp() were making, and eliminates the SGP_HUGE and SGP_NOHUGE modes. Replace a couple of 0s by explicit SHMEM_HUGE_NEVERs; and replace the obscure !shmem_mapping() symlink check by explicit S_ISLNK() - nothing else needs that symlink check, so leave it there in shmem_getpage_gfp(). Link: https://lkml.kernel.org/r/23a77889-2ddc-b030-75cd-44ca27fd4d1@google.comSigned-off-by:
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Hugh Dickins authored
khugepaged's collapse_file() currently uses SGP_NOHUGE to tell shmem_getpage() not to try allocating a huge page, in the very unlikely event that a racing hole-punch removes the swapped or fallocated page as soon as i_pages lock is dropped. We want to consolidate shmem's huge decisions, removing SGP_HUGE and SGP_NOHUGE; but cannot quite persuade ourselves that it's okay to regress the protection in this case - Yang Shi points out that the huge page would remain indefinitely, charged to root instead of the intended memcg. collapse_file() should not even allocate a small page in this case: why proceed if someone is punching a hole? SGP_READ is almost the right flag here, except that it optimizes away from a fallocated page, with NULL to tell caller to fill with zeroes (like a hole); whereas collapse_file()'s sequence relies on using a cache page. Add SGP_NOALLOC just for this. There are too many consecutive "if (page"s there in shmem_getpage_gfp(): group it better; and fix the outdated "bring it back from swap" comment. Link: https://lkml.kernel.org/r/1355343b-acf-4653-ef79-6aee40214ac5@google.comSigned-off-by:
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Hugh Dickins authored
shmem_huge_enabled() is about to be enhanced into shmem_is_huge(), so that it can be used more widely throughout: before making functional changes, shift it to its final position (to avoid forward declaration). Link: https://lkml.kernel.org/r/16fec7b7-5c84-415a-8586-69d8bf6a6685@google.comSigned-off-by:
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Hugh Dickins authored
5.14 commit e6be37b2 ("mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()") added transhuge_vma_enabled() as a wrapper for two very different checks (one check is whether the app has marked its address range not to use THPs, the other check is whether the app is running in a hierarchy that has been marked never to use THPs). shmem_huge_enabled() prefers to show those two checks explicitly, as before. Link: https://lkml.kernel.org/r/45e5338-18d-c6f9-c17e-34f510bc1728@google.comSigned-off-by:
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Hugh Dickins authored
There's a block of code in shmem_setattr() to add the inode to shmem_unused_huge_shrink()'s shrinklist when lowering i_size: it dates from before 5.7 changed truncation to do split_huge_page() for itself, and should have been removed at that time. I am over-stating that: split_huge_page() can fail (notably if there's an extra reference to the page at that time), so there might be value in retrying. But there were already retries as truncation worked through the tails, and this addition risks repeating unsuccessful retries indefinitely: I'd rather remove it now, and work on reducing the chance of split_huge_page() failures separately, if we need to. Link: https://lkml.kernel.org/r/b73b3492-8822-18f9-83e2-938528cdde94@google.com Fixes: 71725ed1 ("mm: huge tmpfs: try to split_huge_page() when punching hole") Signed-off-by:
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Hugh Dickins authored
A successful shmem_fallocate() guarantees that the extent has been reserved, even beyond i_size when the FALLOC_FL_KEEP_SIZE flag was used. But that guarantee is broken by shmem_unused_huge_shrink()'s attempts to split huge pages and free their excess beyond i_size; and by other uses of split_huge_page() near i_size. It's sad to add a shmem inode field just for this, but I did not find a better way to keep the guarantee. A flag to say KEEP_SIZE has been used would be cheaper, but I'm averse to unclearable flags. The fallocend field is not perfect either (many disjoint ranges might be fallocated), but good enough; and gains another use later on. Link: https://lkml.kernel.org/r/ca9a146-3a59-6cd3-7f28-e9a044bb1052@google.com Fixes: 779750d2 ("shmem: split huge pages beyond i_size under memory pressure") Signed-off-by:
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Hugh Dickins authored
Patch series "huge tmpfs: shmem_is_huge() fixes and cleanups". A series of huge tmpfs fixes and cleanups. This patch (of 9): shmem_fallocate() goes to a lot of trouble to leave its newly allocated pages !Uptodate, partly to identify and undo them on failure, partly to leave the overhead of clearing them until later. But the huge page case did not skip to the end of the extent, walked through the tail pages one by one, and appeared to work just fine: but in doing so, cleared and Uptodated the huge page, so there was no way to undo it on failure. And by setting Uptodate too soon, it messed up both its nr_falloced and nr_unswapped counts, so that the intended "time to give up" heuristic did not work at all. Now advance immediately to the end of the huge extent, with a comment on why this is more than just an optimization. But although this speeds up huge tmpfs fallocation, it does leave the clearing until first use, and some users may have come to appreciate slow fallocate but fast first use: if they complain, then we can consider adding a pass to clear at the end. Link: https://lkml.kernel.org/r/da632211-8e3e-6b1-aee-ab24734429a0@google.com Link: https://lkml.kernel.org/r/16201bd2-70e-37e2-e89b-5f929430da@google.com Fixes: 800d8c63 ("shmem: add huge pages support") Signed-off-by:
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Miaohe Lin authored
It's bad to extern swap_info[] in .c. Include corresponding header file instead. Link: https://lkml.kernel.org/r/20210812120350.49801-5-linmiaohe@huawei.comSigned-off-by:
Miaohe Lin <linmiaohe@huawei.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Miaohe Lin authored
The forward declaration for shmem_should_replace_page() and shmem_replace_page() is unnecessary. Remove them. Link: https://lkml.kernel.org/r/20210812120350.49801-4-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
mfill_atomic_install_pte() is introduced to install pte and update mmu cache since commit bf6ebd97aba0 ("userfaultfd/shmem: modify shmem_mfill_atomic_pte to use install_pte()"). So we should remove tlbflush.h as update_mmu_cache() is not called here now. Link: https://lkml.kernel.org/r/20210812120350.49801-3-linmiaohe@huawei.comSigned-off-by: -
Miaohe Lin authored
Patch series "Cleanups for shmem". This series contains cleanups to remove unneeded variable, header file, function forward declaration and so on. More details can be found in the respective changelogs. This patch (of 4): The local variable ret is always equal to -ENOMEM and never touched. So remove it and return -ENOMEM directly to simplify the code. Link: https://lkml.kernel.org/r/20210812120350.49801-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210812120350.49801-2-linmiaohe@huawei.comSigned-off-by:
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Sebastian Andrzej Siewior authored
Each CPU has SHMEM_INO_BATCH inodes available in `->ino_batch' which is per-CPU. Access here is serialized by disabling preemption. If the pool is empty, it gets reloaded from `->next_ino'. Access here is serialized by ->stat_lock which is a spinlock_t and can not be acquired with disabled preemption. One way around it would make per-CPU ino_batch struct containing the inode number a local_lock_t. Another solution is to promote ->stat_lock to a raw_spinlock_t. The critical sections are short. The mpol_put() must be moved outside of the critical section to avoid invoking the destructor with disabled preemption. Link: https://lkml.kernel.org/r/20210806142916.jdwkb5bx62q5fwfo@linutronix.deSigned-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by:
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John Hubbard authored
get_kernel_page() was added in 2012 by [1]. It was used for a while for NFS, but then in 2014, a refactoring [2] removed all callers, and it has apparently not been used since. Remove get_kernel_page() because it has no callers. [1] commit 18022c5d ("mm: add get_kernel_page[s] for pinning of kernel addresses for I/O") [2] commit 91f79c43 ("new helper: iov_iter_get_pages_alloc()") Link: https://lkml.kernel.org/r/20210729221847.1165665-1-jhubbard@nvidia.comSigned-off-by:
John Hubbard <jhubbard@nvidia.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by:
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Hugh Dickins authored
We had a recurring situation in which admin procedures setting up swapfiles would race with test preparation clearing away swapfiles; and just occasionally that got stuck on a swapfile "(deleted)" which could never be swapped off. That is not supposed to be possible. 2.6.28 commit f9454548 ("don't unlink an active swapfile") admitted that it was leaving a race window open: now close it. may_delete() makes the IS_SWAPFILE check (amongst many others) before inode_lock has been taken on target: now repeat just that simple check in vfs_unlink() and vfs_rename(), after taking inode_lock. Which goes most of the way to fixing the race, but swapon() must also check after it acquires inode_lock, that the file just opened has not already been unlinked. Link: https://lkml.kernel.org/r/e17b91ad-a578-9a15-5e3-4989e0f999b5@google.com Fixes: f9454548 ("don't unlink an active swapfile") Signed-off-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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John Hubbard authored
try_get_page() is very similar to try_get_compound_head(), and in fact try_get_page() has fallen a little behind in terms of maintenance: try_get_compound_head() handles speculative page references more thoroughly. There are only two try_get_page() callsites, so just call try_get_compound_head() directly from those, and remove try_get_page() entirely. Also, seeing as how this changes try_get_compound_head() into a non-static function, provide some kerneldoc documentation for it. Link: https://lkml.kernel.org/r/20210813044133.1536842-4-jhubbard@nvidia.comSigned-off-by:
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John Hubbard authored
try_grab_page() does the same thing as try_grab_compound_head(..., refs=1, ...), just with a different API. So there is a lot of code duplication there. Change try_grab_page() to call try_grab_compound_head(), while keeping the API contract identical for callers. Also, now that try_grab_compound_head() always has a caller, remove the __maybe_unused annotation. Link: https://lkml.kernel.org/r/20210813044133.1536842-3-jhubbard@nvidia.comSigned-off-by:
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John Hubbard authored
Patch series "A few gup refactorings and documentation updates", v3. While reviewing some of the other things going on around gup.c, I noticed that the documentation was wrong for a few of the routines that I wrote. And then I noticed that there was some significant code duplication too. So this fixes those issues. This is not entirely risk-free, but after looking closely at this, I think it's actually a useful improvement, getting rid of the code duplication here. This patch (of 3): The documentation for try_grab_compound_head() and try_grab_page() has fallen a little out of date. Update and clarify a few points. Also make it kerneldoc-correct, by adding @args documentation. Link: https://lkml.kernel.org/r/20210813044133.1536842-1-jhubbard@nvidia.com Link: https://lkml.kernel.org/r/20210813044133.1536842-2-jhubbard@nvidia.comSigned-off-by:
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Miaohe Lin authored
Use helper PAGE_ALIGNED to check if address is aligned to PAGE_SIZE. Minor readability improvement. Link: https://lkml.kernel.org/r/20210807093620.21347-6-linmiaohe@huawei.comSigned-off-by:
Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
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Miaohe Lin authored
When failed to try_grab_page, put_dev_pagemap() is missed. So pgmap refcnt will leak in this case. Also we remove the check for pgmap against NULL as it's also checked inside the put_dev_pagemap(). [akpm@linux-foundation.org: simplify, cleanup] [akpm@linux-foundation.org: fix return value] Link: https://lkml.kernel.org/r/20210807093620.21347-5-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Indeed, this BUG_ON couldn't catch anything useful. We are sure ret == 0 here because we would already bail out if ret != 0 and ret is untouched till here. Link: https://lkml.kernel.org/r/20210807093620.21347-4-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Remove unneed local variable orig_refs since refs is unchanged now. Link: https://lkml.kernel.org/r/20210807093620.21347-3-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Patch series "Cleanups and fixup for gup". This series contains cleanups to remove unneeded variable, useless BUG_ON and use helper to improve readability. Also we fix a potential pgmap refcnt leak. More details can be found in the respective changelogs. This patch (of 5): Since commit a2beb5f1 ("mm: clean up the last pieces of page fault accountings"), the local variable major is unused. Remove it. Link: https://lkml.kernel.org/r/20210807093620.21347-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210807093620.21347-2-linmiaohe@huawei.comSigned-off-by:
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Jing Yangyang authored
./include/linux/buffer_head.h:412:64-65:WARNING:return of 0/1 in function 'has_bh_in_lru' with return type bool Return statements in functions returning bool should use true/false instead of 1/0. Generated by: scripts/coccinelle/misc/boolreturn.cocci Link: https://lkml.kernel.org/r/20210824055828.58783-1-deng.changcheng@zte.com.cnSigned-off-by:
Jing Yangyang <jing.yangyang@zte.com.cn> Reported-by:
Zeal Robot <zealci@zte.com.cn> Signed-off-by:
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Shakeel Butt authored
Currently cgroup_writeback_by_id calls mem_cgroup_wb_stats() to get dirty pages for a memcg. However mem_cgroup_wb_stats() does a lot more than just get the number of dirty pages. Just directly get the number of dirty pages instead of calling mem_cgroup_wb_stats(). Also cgroup_writeback_by_id() is only called for best-effort dirty flushing, so remove the unused 'nr' parameter and no need to explicitly flush memcg stats. Link: https://lkml.kernel.org/r/20210722182627.2267368-1-shakeelb@google.comSigned-off-by:
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Johannes Weiner authored
pginodesteal is supposed to capture the impact that inode reclaim has on the page cache state. Currently, it doesn't consider shadow pages that get dropped this way, even though this can have a significant impact on paging behavior, memory pressure calculations etc. To improve visibility into these effects, make sure shadow pages get counted when they get dropped through inode reclaim. This changes the return value semantics of invalidate_mapping_pages() semantics slightly, but the only two users are the inode shrinker itsel and a usb driver that logs it for debugging purposes. Link: https://lkml.kernel.org/r/20210614211904.14420-3-hannes@cmpxchg.orgSigned-off-by:
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Johannes Weiner authored
When drop_caches truncates the page cache in an inode it also includes any shadow entries for evicted pages. However, there is a preliminary check on whether the inode has pages: if it has *only* shadow entries, it will skip running truncation on the inode and leave it behind. Fix the check to mapping_empty(), such that it runs truncation on any inode that has cache entries at all. Link: https://lkml.kernel.org/r/20210614211904.14420-2-hannes@cmpxchg.orgSigned-off-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Johannes Weiner authored
The page cache deletion paths all have interrupts enabled, so no need to use irqsafe/irqrestore locking variants. They used to have irqs disabled by the memcg lock added in commit c4843a75 ("memcg: add per cgroup dirty page accounting"), but that has since been replaced by memcg taking the page lock instead, commit 0a31bc97 ("mm: memcontrol: rewrite uncharge AP"). Link: https://lkml.kernel.org/r/20210614211904.14420-1-hannes@cmpxchg.orgSigned-off-by:
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Jan Kara authored
We do some unlocked reads of writeback statistics like avg_write_bandwidth, dirty_ratelimit, or bw_time_stamp. Generally we are fine with getting somewhat out-of-date values but actually getting different values in various parts of the functions because the compiler decided to reload value from original memory location could confuse calculations. Use READ_ONCE for these unlocked accesses and WRITE_ONCE for the updates to be on the safe side. Link: https://lkml.kernel.org/r/20210713104716.22868-5-jack@suse.czSigned-off-by:
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Jan Kara authored
Rename domain_update_bandwidth() to domain_update_dirty_limit(). The original name is a misnomer. The function has nothing to do with a bandwidth, it updates dirty limits. Link: https://lkml.kernel.org/r/20210713104716.22868-4-jack@suse.czSigned-off-by:
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Jan Kara authored
Michael Stapelberg has reported that for workload with short big spikes of writes (GCC linker seem to trigger this frequently) the write throughput is heavily underestimated and tends to steadily sink until it reaches zero. This has rather bad impact on writeback throttling (causing stalls). The problem is that writeback throughput estimate gets updated at most once per 200 ms. One update happens early after we submit pages for writeback (at that point writeout of only small fraction of pages is completed and thus observed throughput is tiny). Next update happens only during the next write spike (updates happen only from inode writeback and dirty throttling code) and if that is more than 1s after previous spike, we decide system was idle and just ignore whatever was written until this moment. Fix the problem by making sure writeback throughput estimate is also updated shortly after writeback completes to get reasonable estimate of throughput for spiky workloads. [jack@suse.cz: avoid division by 0 in wb_update_dirty_ratelimit()] Link: https://lore.kernel.org/lkml/20210617095309.3542373-1-stapelberg+linux@google.com Link: https://lkml.kernel.org/r/20210713104716.22868-3-jack@suse.czSigned-off-by:
Michael Stapelberg <stapelberg+linux@google.com> Tested-by:
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Jan Kara authored
Currently we trigger writeback bandwidth estimation from balance_dirty_pages() and from wb_writeback(). However neither of these need to trigger when the system is relatively idle and writeback is triggered e.g. from fsync(2). Make sure writeback estimates happen reliably by triggering them from do_writepages(). Link: https://lkml.kernel.org/r/20210713104716.22868-2-jack@suse.czSigned-off-by:
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Jan Kara authored
Patch series "writeback: Fix bandwidth estimates", v4. Fix estimate of writeback throughput when device is not fully busy doing writeback. Michael Stapelberg has reported that such workload (e.g. generated by linking) tends to push estimated throughput down to 0 and as a result writeback on the device is practically stalled. The first three patches fix the reported issue, the remaining two patches are unrelated cleanups of problems I've noticed when reading the code. This patch (of 4): Track number of inodes under writeback for each bdi_writeback structure. We will use this to decide whether wb does any IO and so we can estimate its writeback throughput. In principle we could use number of pages under writeback (WB_WRITEBACK counter) for this however normal percpu counter reads are too inaccurate for our purposes and summing the counter is too expensive. Link: https://lkml.kernel.org/r/20210713104519.16394-1-jack@suse.cz Link: https://lkml.kernel.org/r/20210713104716.22868-1-jack@suse.czSigned-off-by:
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liuhailong authored
Print NR_KERNEL_MISC_RECLAIMABLE stat from show_free_areas() so users can check whether the shrinker is working correctly and to show the current memory usage. Link: https://lkml.kernel.org/r/20210813104725.4562-1-liuhailong@oppo.comSigned-off-by:
liuhailong <liuhailong@oppo.com> Signed-off-by:
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Matthew Wilcox (Oracle) authored
A recent lockdep report included these lines: [ 96.177910] 3 locks held by containerd/770: [ 96.177934] #0: ffff88810815ea28 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x115/0x770 [ 96.177999] #1: ffffffff82915020 (rcu_read_lock){....}-{1:2}, at: get_swap_device+0x33/0x140 [ 96.178057] #2: ffffffff82955ba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30 While it was not useful to that bug report to know where the reclaim lock had been acquired, it might be useful under other circumstances. Allow the caller of __fs_reclaim_acquire to specify the instruction pointer to use. Link: https://lkml.kernel.org/r/20210719185709.1755149-1-willy@infradead.orgSigned-off-by:Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Omar Sandoval <osandov@fb.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Signed-off-by:
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Gavin Shan authored
In page table entry modifying tests, set_xxx_at() are used to populate the page table entries. On ARM64, PG_arch_1 (PG_dcache_clean) flag is set to the target page flag if execution permission is given. The logic exits since commit 4f04d8f0 ("arm64: MMU definitions"). The page flag is kept when the page is free'd to buddy's free area list. However, it will trigger page checking failure when it's pulled from the buddy's free area list, as the following warning messages indicate. BUG: Bad page state in process memhog pfn:08000 page:0000000015c0a628 refcount:0 mapcount:0 \ mapping:0000000000000000 index:0x1 pfn:0x8000 flags: 0x7ffff8000000800(arch_1|node=0|zone=0|lastcpupid=0xfffff) raw: 07ffff8000000800 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag(s) set This fixes the issue by clearing PG_arch_1 through flush_dcache_page() after set_xxx_at() is called. For architectures other than ARM64, the unexpected overhead of cache flushing is acceptable. Link: https://lkml.kernel.org/r/20210809092631.1888748-13-gshan@redhat.com Fixes: a5c3b9ff ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers") Signed-off-by:
Gavin Shan <gshan@redhat.com> Reviewed-by:
Anshuman Khandual <anshuman.khandual@arm.com> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> [powerpc 8xx] Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> [s390] Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chunyu Hu <chuhu@redhat.com> Cc: Qian Cai <cai@lca.pw> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
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Gavin Shan authored
The variables used by old implementation isn't needed as we switched to "struct pgtable_debug_args". Lets remove them and related code in debug_vm_pgtable(). Link: https://lkml.kernel.org/r/20210809092631.1888748-12-gshan@redhat.comSigned-off-by:
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Gavin Shan authored
This uses struct pgtable_debug_args in PGD/P4D modifying tests. No allocated huge page is used in these tests. Besides, the unused variable @saved_p4dp and @saved_pudp are dropped. Link: https://lkml.kernel.org/r/20210809092631.1888748-11-gshan@redhat.comSigned-off-by:
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