From dfb8ae567835425d27db8acc6c9fc5db88d38e2b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 17:13:40 -0400 Subject: [PATCH] writeback: let balance_dirty_pages() work on the matching cgroup bdi_writeback Currently, balance_dirty_pages() always work on bdi->wb. This patch updates it to work on the wb (bdi_writeback) matching memcg and blkcg of the current task as that's what the inode is being dirtied against. balance_dirty_pages_ratelimited() now pins the current wb and passes it to balance_dirty_pages(). As no filesystem has FS_CGROUP_WRITEBACK yet, this doesn't lead to visible behavior differences. v2: Updated for per-inode wb association. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara Signed-off-by: Jens Axboe --- mm/page-writeback.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 4d0a9da2de6b..e31dea94d116 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1337,6 +1337,7 @@ static inline void wb_dirty_limits(struct bdi_writeback *wb, * perform some writeout. */ static void balance_dirty_pages(struct address_space *mapping, + struct bdi_writeback *wb, unsigned long pages_dirtied) { unsigned long nr_reclaimable; /* = file_dirty + unstable_nfs */ @@ -1352,8 +1353,7 @@ static void balance_dirty_pages(struct address_space *mapping, unsigned long task_ratelimit; unsigned long dirty_ratelimit; unsigned long pos_ratio; - struct backing_dev_info *bdi = inode_to_bdi(mapping->host); - struct bdi_writeback *wb = &bdi->wb; + struct backing_dev_info *bdi = wb->bdi; bool strictlimit = bdi->capabilities & BDI_CAP_STRICTLIMIT; unsigned long start_time = jiffies; @@ -1575,14 +1575,20 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; */ void balance_dirty_pages_ratelimited(struct address_space *mapping) { - struct backing_dev_info *bdi = inode_to_bdi(mapping->host); - struct bdi_writeback *wb = &bdi->wb; + struct inode *inode = mapping->host; + struct backing_dev_info *bdi = inode_to_bdi(inode); + struct bdi_writeback *wb = NULL; int ratelimit; int *p; if (!bdi_cap_account_dirty(bdi)) return; + if (inode_cgwb_enabled(inode)) + wb = wb_get_create_current(bdi, GFP_KERNEL); + if (!wb) + wb = &bdi->wb; + ratelimit = current->nr_dirtied_pause; if (wb->dirty_exceeded) ratelimit = min(ratelimit, 32 >> (PAGE_SHIFT - 10)); @@ -1616,7 +1622,9 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) preempt_enable(); if (unlikely(current->nr_dirtied >= ratelimit)) - balance_dirty_pages(mapping, current->nr_dirtied); + balance_dirty_pages(mapping, wb, current->nr_dirtied); + + wb_put(wb); } EXPORT_SYMBOL(balance_dirty_pages_ratelimited);