Subject: + writeback-fix-occasional-slow-sync1.patch added to -mm tree To: jack@xxxxxxx,fengguang.wu@xxxxxxxxx,taysom@xxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Thu, 15 Aug 2013 15:15:42 -0700 The patch titled Subject: writeback: fix occasional slow sync(1) has been added to the -mm tree. Its filename is writeback-fix-occasional-slow-sync1.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/writeback-fix-occasional-slow-sync1.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/writeback-fix-occasional-slow-sync1.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Jan Kara <jack@xxxxxxx> Subject: writeback: fix occasional slow sync(1) In case when system contains no dirty pages, wakeup_flusher_threads() will submit WB_SYNC_NONE writeback for 0 pages so wb_writeback() exits immediately without doing anything, even though there are dirty inodes in the system. Thus sync(1) will write all the dirty inodes from a WB_SYNC_ALL writeback pass which is slow. Fix the problem by using get_nr_dirty_pages() in wakeup_flusher_threads() instead of calculating number of dirty pages manually. That function also takes number of dirty inodes into account. Signed-off-by: Jan Kara <jack@xxxxxxx> Reported-by: Paul Taysom <taysom@xxxxxxxxxxxx> Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/fs-writeback.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN fs/fs-writeback.c~writeback-fix-occasional-slow-sync1 fs/fs-writeback.c --- a/fs/fs-writeback.c~writeback-fix-occasional-slow-sync1 +++ a/fs/fs-writeback.c @@ -1049,10 +1049,8 @@ void wakeup_flusher_threads(long nr_page { struct backing_dev_info *bdi; - if (!nr_pages) { - nr_pages = global_page_state(NR_FILE_DIRTY) + - global_page_state(NR_UNSTABLE_NFS); - } + if (!nr_pages) + nr_pages = get_nr_dirty_pages(); rcu_read_lock(); list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { _ Patches currently in -mm which might be from jack@xxxxxxx are thp-account-anon-transparent-huge-pages-into-nr_anon_pages.patch mm-cleanup-add_to_page_cache_locked.patch thp-move-maybe_pmd_mkwrite-out-of-mk_huge_pmd.patch thp-do_huge_pmd_anonymous_page-cleanup.patch thp-consolidate-code-between-handle_mm_fault-and-do_huge_pmd_anonymous_page.patch writeback-fix-occasional-slow-sync1.patch lib-radix-treec-make-radix_tree_node_alloc-work-correctly-within-interrupt.patch linux-next.patch fs-bump-inode-and-dentry-counters-to-long.patch super-fix-calculation-of-shrinkable-objects-for-small-numbers.patch dcache-convert-dentry_statnr_unused-to-per-cpu-counters.patch dentry-move-to-per-sb-lru-locks.patch dcache-remove-dentries-from-lru-before-putting-on-dispose-list.patch mm-new-shrinker-api.patch shrinker-convert-superblock-shrinkers-to-new-api.patch list-add-a-new-lru-list-type.patch inode-convert-inode-lru-list-to-generic-lru-list-code.patch dcache-convert-to-use-new-lru-list-infrastructure.patch list_lru-per-node-list-infrastructure.patch list_lru-per-node-api.patch shrinker-add-node-awareness.patch vmscan-per-node-deferred-work.patch fs-convert-inode-and-dentry-shrinking-to-be-node-aware.patch xfs-convert-buftarg-lru-to-generic-code.patch xfs-rework-buffer-dispose-list-tracking.patch xfs-convert-dquot-cache-lru-to-list_lru.patch fs-convert-fs-shrinkers-to-new-scan-count-api.patch drivers-convert-shrinkers-to-new-count-scan-api.patch i915-bail-out-earlier-when-shrinker-cannot-acquire-mutex.patch shrinker-convert-remaining-shrinkers-to-count-scan-api.patch hugepage-convert-huge-zero-page-shrinker-to-new-shrinker-api.patch shrinker-kill-old-shrink-api.patch list_lru-dynamically-adjust-node-arrays.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html