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* mm/writeback: Improve __folio_mark_dirty() commentMatthew Wilcox (Oracle)2022-01-021-1/+5
| | | | | | | | Add some notes about how this function needs to be called. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
* folio: Add a function to get the host inode for a folioDavid Howells2021-11-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a convenience function, folio_inode() that will get the host inode from a folio's mapping. Changes: ver #3: - Fix mistake in function description[2]. ver #2: - Fix contradiction between doc and implementation by disallowing use with swap caches[1]. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dominique Martinet <asmadeus@codewreck.org> Tested-by: kafs-testing@auristor.com Link: https://lore.kernel.org/r/YST8OcVNy02Rivbm@casper.infradead.org/ [1] Link: https://lore.kernel.org/r/YYKLkBwQdtn4ja+i@casper.infradead.org/ [2] Link: https://lore.kernel.org/r/162880453171.3369675.3704943108660112470.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162981151155.1901565.7010079316994382707.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005744370.2472992.18324470937328925723.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163584184628.4023316.9386282630968981869.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/163649325519.309189.15072332908703129455.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/163657850401.834781.1031963517399283294.stgit@warthog.procyon.org.uk/ # v5
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-11-061-2/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
| * mm/vmscan: centralise timeout values for reclaim_throttleMel Gorman2021-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Neil Brown raised concerns about callers of reclaim_throttle specifying a timeout value. The original timeout values to congestion_wait() were probably pulled out of thin air or copy&pasted from somewhere else. This patch centralises the timeout values and selects a timeout based on the reason for reclaim throttling. These figures are also pulled out of the same thin air but better values may be derived Running a workload that is throttling for inappropriate periods and tracing mm_vmscan_throttled can be used to pick a more appropriate value. Excessive throttling would pick a lower timeout where as excessive CPU usage in reclaim context would select a larger timeout. Ideally a large value would always be used and the wakeups would occur before a timeout but that requires careful testing. Link: https://lkml.kernel.org/r/20211022144651.19914-7-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Darrick J . Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/writeback: throttle based on page writeback instead of congestionMel Gorman2021-11-061-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_writepages throttles on congestion if the writepages() fails due to a lack of memory but congestion_wait() is partially broken as the congestion state is not updated for all BDIs. This patch stalls waiting for a number of pages to complete writeback that located on the local node. The main weakness is that there is no correlation between the location of the inode's pages and locality but that is still better than congestion_wait. Link: https://lkml.kernel.org/r/20211022144651.19914-5-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Darrick J . Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/writeback: Add folio_write_oneMatthew Wilcox (Oracle)2021-10-181-15/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Transform write_one_page() into folio_write_one() and add a compatibility wrapper. Also move the declaration to pagemap.h as this is page cache functionality that doesn't need to be used by the rest of the kernel. Saves 58 bytes of kernel text. While folio_write_one() is 101 bytes smaller than write_one_page(), the inlined call to page_folio() expands each caller. There are fewer than ten callers so it doesn't seem worth putting a wrapper in the core. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Howells <dhowells@redhat.com>
* | mm/writeback: Add folio_redirty_for_writepage()Matthew Wilcox (Oracle)2021-10-181-10/+20
| | | | | | | | | | | | | | | | | | | | | | Reimplement redirty_page_for_writepage() as a wrapper around folio_redirty_for_writepage(). Account the number of pages in the folio, add kernel-doc and move the prototype to writeback.h. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_account_redirty()Matthew Wilcox (Oracle)2021-10-181-13/+19
| | | | | | | | | | | | | | | | | | | | | | | | Account the number of pages in the folio that we're redirtying. Turn account_page_dirty() into a wrapper around it. Also turn the comment on folio_account_redirty() into kernel-doc and edit it slightly so it makes sense to its potential callers. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_clear_dirty_for_io()Matthew Wilcox (Oracle)2021-10-181-31/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Transform clear_page_dirty_for_io() into folio_clear_dirty_for_io() and add a compatibility wrapper. Also move the declaration to pagemap.h as this is page cache functionality that doesn't need to be used by the rest of the kernel. Increases the size of the kernel by 79 bytes. While we remove a few calls to compound_head(), we add a call to folio_nr_pages() to get the stats correct for the eventual support of multi-page folios. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_cancel_dirty()Matthew Wilcox (Oracle)2021-10-181-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | Turn __cancel_dirty_page() into __folio_cancel_dirty() and add wrappers. Move the prototypes into pagemap.h since this is page cache functionality. Saves 44 bytes of kernel text in total; 33 bytes from __folio_cancel_dirty and 11 from two callers of cancel_dirty_page(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_account_cleaned()Matthew Wilcox (Oracle)2021-10-181-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | Get the statistics right; compound pages were being accounted as a single page. This didn't matter before now as no filesystem which supported compound pages did writeback. Also move the declaration to pagemap.h since this is part of the page cache. Add a wrapper for account_page_cleaned(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add filemap_dirty_folio()Matthew Wilcox (Oracle)2021-10-181-29/+31
| | | | | | | | | | | | | | | | | | | | | | | | Reimplement __set_page_dirty_nobuffers() as a wrapper around filemap_dirty_folio(). Eventually folio_mark_dirty() will pass the folio's mapping to the address space's ->dirty_folio() operation, so add the parameter to filemap_dirty_folio() now. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Convert tracing writeback_page_template to foliosMatthew Wilcox (Oracle)2021-10-181-3/+3
| | | | | | | | | | | | | | | | | | Rename writeback_dirty_page() to writeback_dirty_folio() and wait_on_page_writeback() to folio_wait_writeback(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add __folio_mark_dirty()Matthew Wilcox (Oracle)2021-10-181-20/+21
| | | | | | | | | | | | | | | | | | | | Turn __set_page_dirty() into a wrapper around __folio_mark_dirty(). Convert account_page_dirtied() into folio_account_dirtied() and account the number of pages in the folio to support multi-page folios. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_mark_dirty()Matthew Wilcox (Oracle)2021-10-181-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reimplement set_page_dirty() as a wrapper around folio_mark_dirty(). There is no change to filesystems as they were already being called with the compound_head of the page being marked dirty. We avoid several calls to compound_head(), both statically (through using folio_test_dirty() instead of PageDirty() and dynamically by calling folio_mapping() instead of page_mapping(). Also return bool instead of int to show the range of values actually returned, and add kernel-doc. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add folio_start_writeback()Matthew Wilcox (Oracle)2021-10-181-19/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename set_page_writeback() to folio_start_writeback() to match folio_end_writeback(). Do not bother with wrappers that return void; callers are perfectly capable of ignoring return values. Add wrappers for set_page_writeback(), set_page_writeback_keepwrite() and test_set_page_writeback() for compatibililty with existing filesystems. The main advantage of this patch is getting the statistics right, although it does eliminate a couple of calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Add __folio_end_writeback()Matthew Wilcox (Oracle)2021-10-181-14/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | test_clear_page_writeback() is actually an mm-internal function, although it's named as if it's a pagecache function. Move it to mm/internal.h, rename it to __folio_end_writeback() and change the return type to bool. The conversion from page to folio is mostly about accounting the number of pages being written back, although it does eliminate a couple of calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add()Matthew Wilcox (Oracle)2021-10-181-11/+11
| | | | | | | | | | | | | | | | | | | | Allow for accounting N pages at once instead of one page at a time. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
* | flex_proportions: Allow N events instead of 1Matthew Wilcox (Oracle)2021-10-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | When batching events (such as writing back N pages in a single I/O), it is better to do one flex_proportion operation instead of N. There is only one caller of __fprop_inc_percpu_max(), and it's the one we're going to change in the next patch, so rename it instead of adding a compatibility wrapper. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz>
* | mm/filemap: Add folio_wait_bit()Matthew Wilcox (Oracle)2021-09-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename wait_on_page_bit() to folio_wait_bit(). We must always wait on the folio, otherwise we won't be woken up due to the tail page hashing to a different bucket from the head page. This commit shrinks the kernel by 770 bytes, mostly due to moving the page waitqueue lookup into folio_wait_bit_common(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com>
* | mm/writeback: Add folio_wait_stable()Matthew Wilcox (Oracle)2021-09-271-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move wait_for_stable_page() into the folio compatibility file. folio_wait_stable() avoids a call to compound_head() and is 14 bytes smaller than wait_for_stable_page() was. The net text size grows by 16 bytes as a result of this patch. We can also remove thp_head() as this was the last user. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: David Howells <dhowells@redhat.com>
* | mm/writeback: Add folio_wait_writeback()Matthew Wilcox (Oracle)2021-09-271-15/+33
|/ | | | | | | | | | | | | | | | | | | | | wait_on_page_writeback_killable() only has one caller, so convert it to call folio_wait_writeback_killable(). For the wait_on_page_writeback() callers, add a compatibility wrapper around folio_wait_writeback(). Turning PageWriteback() into folio_test_writeback() eliminates a call to compound_head() which saves 8 bytes and 15 bytes in the two functions. Unfortunately, that is more than offset by adding the wait_on_page_writeback compatibility wrapper for a net increase in text of 7 bytes. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-09-031-38/+83
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
| * writeback: use READ_ONCE for unlocked reads of writeback statsJan Kara2021-09-031-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Michael Stapelberg <stapelberg+linux@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * writeback: rename domain_update_bandwidth()Jan Kara2021-09-031-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | 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.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Michael Stapelberg <stapelberg+linux@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * writeback: fix bandwidth estimate for spiky workloadJan Kara2021-09-031-14/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.cz Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Michael Stapelberg <stapelberg+linux@google.com> Tested-by: Michael Stapelberg <stapelberg+linux@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * writeback: reliably update bandwidth estimationJan Kara2021-09-031-12/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Michael Stapelberg <stapelberg+linux@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * writeback: track number of inodes under writebackJan Kara2021-09-031-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Michael Stapelberg <stapelberg+linux@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: hide laptop_mode_wb_timer entirely behind the BDI APIChristoph Hellwig2021-08-091-2/+0
|/ | | | | | | | | | | | | Don't leak the detaŃ–ls of the timer into the block layer, instead initialize the timer in bdi_alloc and delete it in bdi_unregister. Note that this means the timer is initialized (but not armed) for non-block queues as well now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-blockLinus Torvalds2021-06-301-5/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: - disk events cleanup (Christoph) - gendisk and request queue allocation simplifications (Christoph) - bdev_disk_changed cleanups (Christoph) - IO priority improvements (Bart) - Chained bio completion trace fix (Edward) - blk-wbt fixes (Jan) - blk-wbt enable/disable fix (Zhang) - Scheduler dispatch improvements (Jan, Ming) - Shared tagset scheduler improvements (John) - BFQ updates (Paolo, Luca, Pietro) - BFQ lock inversion fix (Jan) - Documentation improvements (Kir) - CLONE_IO block cgroup fix (Tejun) - Remove of ancient and deprecated block dump feature (zhangyi) - Discard merge fix (Ming) - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas, Yang) * tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits) block: fix discard request merge block/mq-deadline: Remove a WARN_ON_ONCE() call blk-mq: update hctx->dispatch_busy in case of real scheduler blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block: pass a gendisk to bdev_disk_changed block: move bdev_disk_changed block: add the events* attributes to disk_attrs block: move the disk events code to a separate file block: fix trace completion for chained bio block/partitions/msdos: Fix typo inidicator -> indicator block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising blk-wbt: make sure throttle is enabled properly blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() ...
| * block_dump: remove block_dump featurezhangyi (F)2021-05-241-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have already delete block_dump feature in mark_inode_dirty() because it can be replaced by tracepoints, now we also remove the part in submit_bio() for the same reason. The part of block dump feature in submit_bio() dump the write process, write region and sectors on the target disk into kernel message. it can be replaced by block_bio_queue tracepoint in submit_bio_checks(), so we do not need block_dump anymore, remove the whole block_dump feature. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210313030146.2882027-3-yi.zhang@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | fs: remove noop_set_page_dirty()Matthew Wilcox (Oracle)2021-06-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use __set_page_dirty_no_writeback() instead. This will set the dirty bit on the page, which will be used to avoid calling set_page_dirty() in the future. It will have no effect on actually writing the page back, as the pages are not on any LRU lists. [akpm@linux-foundation.org: export __set_page_dirty_no_writeback() to modules] Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/writeback: use __set_page_dirty in __set_page_dirty_nobuffersMatthew Wilcox (Oracle)2021-06-291-9/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is fundamentally the same code, so just call it instead of duplicating it. Link: https://lkml.kernel.org/r/20210615162342.1669332-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/writeback: move __set_page_dirty() to core mmMatthew Wilcox (Oracle)2021-06-291-1/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Further set_page_dirty cleanups". Prompted by Christoph's recent patches, here are some more patches to improve the state of set_page_dirty(). They're all from the folio tree, so they've been tested to a certain extent. This patch (of 6): Nothing in __set_page_dirty() is specific to buffer_head, so move it to mm/page-writeback.c. That removes the only caller of account_page_dirtied() outside of page-writeback.c, so make it static. Link: https://lkml.kernel.org/r/20210615162342.1669332-1-willy@infradead.org Link: https://lkml.kernel.org/r/20210615162342.1669332-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: require ->set_page_dirty to be explicitly wired upChristoph Hellwig2021-06-291-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just wire that method up for the missing instances. [hch@lst.de: ecryptfs: add a ->set_page_dirty cludge] Link: https://lkml.kernel.org/r/20210624125250.536369-1-hch@lst.de Link: https://lkml.kernel.org/r/20210614061512.3966143-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Tyler Hicks <code@tyhicks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/page-writeback: use __this_cpu_inc() in account_page_dirtied()Chi Wu2021-06-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As account_page_dirtied() was always protected by xa_lock_irqsave(), so using __this_cpu_inc() is better. Link: https://lkml.kernel.org/r/20210512144742.4764-1-wuchi.zero@gmail.com Signed-off-by: Chi Wu <wuchi.zero@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Howard Cochran <hcochran@kernelspring.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/page-writeback: update the comment of Dirty position controlChi Wu2021-06-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the value of pos_ratio_polynom() clamp between 0 and 2LL << RATELIMIT_CALC_SHIFT, the global control line should be consistent with it. Link: https://lkml.kernel.org/r/20210511103606.3732-1-wuchi.zero@gmail.com Signed-off-by: Chi Wu <wuchi.zero@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Cc: Howard Cochran <hcochran@kernelspring.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/page-writeback: Fix performance when BDI's share of ratio is 0.Chi Wu2021-06-291-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix performance when BDI's share of ratio is 0. The issue is similar to commit 74d369443325 ("writeback: Fix performance regression in wb_over_bg_thresh()"). Balance_dirty_pages and the writeback worker will also disagree on whether writeback when a BDI uses BDI_CAP_STRICTLIMIT and BDI's share of the thresh ratio is zero. For example, A thread on cpu0 writes 32 pages and then balance_dirty_pages, it will wake up background writeback and pauses because wb_dirty > wb->wb_thresh = 0 (share of thresh ratio is zero). A thread may runs on cpu0 again because scheduler prefers pre_cpu. Then writeback worker may runs on other cpus(1,2..) which causes the value of wb_stat(wb, WB_RECLAIMABLE) in wb_over_bg_thresh is 0 and does not writeback and returns. Thus, balance_dirty_pages keeps looping, sleeping and then waking up the worker who will do nothing. It remains stuck in this state until the writeback worker hit the right dirty cpu or the dirty pages expire. The fix that we should get the wb_stat_sum radically when thresh is low. Link: https://lkml.kernel.org/r/20210428225046.16301-1-wuchi.zero@gmail.com Signed-off-by: Chi Wu <wuchi.zero@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: page-writeback: kill get_writeback_state() commentsKefeng Wang2021-06-291-6/+3
|/ | | | | | | | | The get_writeback_state() has gone since 2006, kill related comments. Link: https://lkml.kernel.org/r/20210508125026.56600-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix typos in commentsIngo Molnar2021-05-071-2/+2
| | | | | | | | | | | | | | Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page-writeback: simplify memcg handling in test_clear_page_writeback()Johannes Weiner2021-04-301-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Page writeback doesn't hold a page reference, which allows truncate to free a page the second PageWriteback is cleared. This used to require special attention in test_clear_page_writeback(), where we had to be careful not to rely on the unstable page->memcg binding and look up all the necessary information before clearing the writeback flag. Since commit 073861ed77b6 ("mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)") test_clear_page_writeback() is called with an explicit reference on the page, and this dance is no longer needed. Use unlock_page_memcg() and dec_lruvec_page_state() directly. This removes the last user of the lock_page_memcg() return value, change it to void. Touch up the comments in there as well. This also removes the last extern user of __unlock_page_memcg(), make it static. Further, it removes the last user of dec_lruvec_state(), delete it, along with a few other unused helpers. Link: https://lkml.kernel.org/r/YCQbYAWg4nvBFL6h@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/writeback: Add wait_on_page_writeback_killableMatthew Wilcox (Oracle)2021-03-231-0/+16
| | | | | | | | | | | | This is the killable version of wait_on_page_writeback. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: kafs-testing@auristor.com cc: linux-afs@lists.infradead.org cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20210320054104.1300774-3-willy@infradead.org
* mm: make wait_on_page_writeback() wait for multiple pending writebacksLinus Torvalds2021-01-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ever since commit 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") we've had some very occasional reports of BUG_ON(PageWriteback) in write_cache_pages(), which we thought we already fixed in commit 073861ed77b6 ("mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)"). But syzbot just reported another one, even with that commit in place. And it turns out that there's a simpler way to trigger the BUG_ON() than the one Hugh found with page re-use. It all boils down to the fact that the page writeback is ostensibly serialized by the page lock, but that isn't actually really true. Yes, the people _setting_ writeback all do so under the page lock, but the actual clearing of the bit - and waking up any waiters - happens without any page lock. This gives us this fairly simple race condition: CPU1 = end previous writeback CPU2 = start new writeback under page lock CPU3 = write_cache_pages() CPU1 CPU2 CPU3 ---- ---- ---- end_page_writeback() test_clear_page_writeback(page) ... delayed... lock_page(); set_page_writeback() unlock_page() lock_page() wait_on_page_writeback(); wake_up_page(page, PG_writeback); .. wakes up CPU3 .. BUG_ON(PageWriteback(page)); where the BUG_ON() happens because we woke up the PG_writeback bit becasue of the _previous_ writeback, but a new one had already been started because the clearing of the bit wasn't actually atomic wrt the actual wakeup or serialized by the page lock. The reason this didn't use to happen was that the old logic in waiting on a page bit would just loop if it ever saw the bit set again. The nice proper fix would probably be to get rid of the whole "wait for writeback to clear, and then set it" logic in the writeback path, and replace it with an atomic "wait-to-set" (ie the same as we have for page locking: we set the page lock bit with a single "lock_page()", not with "wait for lock bit to clear and then set it"). However, out current model for writeback is that the waiting for the writeback bit is done by the generic VFS code (ie write_cache_pages()), but the actual setting of the writeback bit is done much later by the filesystem ".writepages()" function. IOW, to make the writeback bit have that same kind of "wait-to-set" behavior as we have for page locking, we'd have to change our roughly ~50 different writeback functions. Painful. Instead, just make "wait_on_page_writeback()" loop on the very unlikely situation that the PG_writeback bit is still set, basically re-instating the old behavior. This is very non-optimal in case of contention, but since we only ever set the bit under the page lock, that situation is controlled. Reported-by: syzbot+2fc0712f8f8b8b8fa0ef@syzkaller.appspotmail.com Fixes: 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") Acked-by: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)Hugh Dickins2020-11-241-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Twice now, when exercising ext4 looped on shmem huge pages, I have crashed on the PF_ONLY_HEAD check inside PageWaiters(): ext4_finish_bio() calling end_page_writeback() calling wake_up_page() on tail of a shmem huge page, no longer an ext4 page at all. The problem is that PageWriteback is not accompanied by a page reference (as the NOTE at the end of test_clear_page_writeback() acknowledges): as soon as TestClearPageWriteback has been done, that page could be removed from page cache, freed, and reused for something else by the time that wake_up_page() is reached. https://lore.kernel.org/linux-mm/20200827122019.GC14765@casper.infradead.org/ Matthew Wilcox suggested avoiding or weakening the PageWaiters() tail check; but I'm paranoid about even looking at an unreferenced struct page, lest its memory might itself have already been reused or hotremoved (and wake_up_page_bit() may modify that memory with its ClearPageWaiters()). Then on crashing a second time, realized there's a stronger reason against that approach. If my testing just occasionally crashes on that check, when the page is reused for part of a compound page, wouldn't it be much more common for the page to get reused as an order-0 page before reaching wake_up_page()? And on rare occasions, might that reused page already be marked PageWriteback by its new user, and already be waited upon? What would that look like? It would look like BUG_ON(PageWriteback) after wait_on_page_writeback() in write_cache_pages() (though I have never seen that crash myself). Matthew Wilcox explaining this to himself: "page is allocated, added to page cache, dirtied, writeback starts, --- thread A --- filesystem calls end_page_writeback() test_clear_page_writeback() --- context switch to thread B --- truncate_inode_pages_range() finds the page, it doesn't have writeback set, we delete it from the page cache. Page gets reallocated, dirtied, writeback starts again. Then we call write_cache_pages(), see PageWriteback() set, call wait_on_page_writeback() --- context switch back to thread A --- wake_up_page(page, PG_writeback); ... thread B is woken, but because the wakeup was for the old use of the page, PageWriteback is still set. Devious" And prior to 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") this would have been much less likely: before that, wake_page_function()'s non-exclusive case would stop walking and not wake if it found Writeback already set again; whereas now the non-exclusive case proceeds to wake. I have not thought of a fix that does not add a little overhead: the simplest fix is for end_page_writeback() to get_page() before calling test_clear_page_writeback(), then put_page() after wake_up_page(). Was there a chance of missed wakeups before, since a page freed before reaching wake_up_page() would have PageWaiters cleared? I think not, because each waiter does hold a reference on the page. This bug comes when the old use of the page, the one we do TestClearPageWriteback on, had *no* waiters, so no additional page reference beyond the page cache (and whoever racily freed it). The reuse of the page has a waiter holding a reference, and its own PageWriteback set; but the belated wake_up_page() has woken the reuse to hit that BUG_ON(PageWriteback). Reported-by: syzbot+3622cea378100f45d59f@syzkaller.appspotmail.com Reported-by: Qian Cai <cai@lca.pw> Fixes: 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page-writeback: support tail pages in wait_for_stable_pageMatthew Wilcox (Oracle)2020-10-161-0/+1
| | | | | | | | | | | | | page->mapping is undefined for tail pages, so operate exclusively on the head page. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: SeongJae Park <sjpark@amazon.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Link: https://lkml.kernel.org/r/20200908195539.25896-11-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flagChristoph Hellwig2020-09-241-6/+6
| | | | | | | | | | | | Replace the two negative flags that are always used together with a single positive flag that indicates the writeback capability instead of two related non-capabilities. Also remove the pointless wrappers to just check the flag. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bdi: invert BDI_CAP_NO_ACCT_WBChristoph Hellwig2020-09-241-2/+2
| | | | | | | | | | | Replace BDI_CAP_NO_ACCT_WB with a positive BDI_CAP_WRITEBACK_ACCT to make the checks more obvious. Also remove the pointless bdi_cap_account_writeback wrapper that just obsfucates the check. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flagChristoph Hellwig2020-09-241-1/+1
| | | | | | | | | | | | | | | | | | The BDI_CAP_STABLE_WRITES is one of the few bits of information in the backing_dev_info shared between the block drivers and the writeback code. To help untangling the dependency replace it with a queue flag and a superblock flag derived from it. This also helps with the case of e.g. a file system requiring stable writes due to its own checksumming, but not forcing it on other users of the block device like the swap code. One downside is that we an't support the stable_pages_required bdi attribute in sysfs anymore. It is replaced with a queue attribute which also is writable for easier testing. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* mm: remove vm_total_pagesDavid Hildenbrand2020-08-071-4/+2
| | | | | | | | | | | | | | | | | | | | | The global variable "vm_total_pages" is a relic from older days. There is only a single user that reads the variable - build_all_zonelists() - and the first thing it does is update it. Use a local variable in build_all_zonelists() instead and remove the global variable. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page-writeback: fix a typo in comment "effictive"->"effective"Ethon Paul2020-06-041-1/+1
| | | | | | | | | There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200411003513.14613-1-ethp@qq.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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