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authorTejun Heo <tj@kernel.org>2015-05-22 17:13:47 -0400
committerJens Axboe <axboe@fb.com>2015-06-02 08:33:36 -0600
commit95a46c65e3c09edb9f17dabf2dc16670cd328739 (patch)
tree2ff8187223f5f5671394dd9ee84719f3ff934a14 /mm/backing-dev.c
parent766a9d6e60578f1ef6de71f89f022084f8bffc82 (diff)
downloadlinux-95a46c65e3c09edb9f17dabf2dc16670cd328739.tar.bz2
writeback: make bdi_has_dirty_io() take multiple bdi_writeback's into account
bdi_has_dirty_io() used to only reflect whether the root wb (bdi_writeback) has dirty inodes. For cgroup writeback support, it needs to take all active wb's into account. If any wb on the bdi has dirty inodes, bdi_has_dirty_io() should return true. To achieve that, as inode_wb_list_{move|del}_locked() now keep track of the dirty state transition of each wb, the number of dirty wbs can be counted in the bdi; however, bdi is already aggregating wb->avg_write_bandwidth which can easily be guaranteed to be > 0 when there are any dirty inodes by ensuring wb->avg_write_bandwidth can't dip below 1. bdi_has_dirty_io() can simply test whether bdi->tot_write_bandwidth is zero or not. While this bumps the value of wb->avg_write_bandwidth to one when it used to be zero, this shouldn't cause any meaningful behavior difference. bdi_has_dirty_io() is made an inline function which tests whether ->tot_write_bandwidth is non-zero. Also, WARN_ON_ONCE()'s on its value are added to inode_wb_list_{move|del}_locked(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r--mm/backing-dev.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 161ddf12b862..d2f16fc9069a 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -256,11 +256,6 @@ static int __init default_bdi_init(void)
}
subsys_initcall(default_bdi_init);
-bool bdi_has_dirty_io(struct backing_dev_info *bdi)
-{
- return wb_has_dirty_io(&bdi->wb);
-}
-
/*
* This function is used when the first inode for this wb is marked dirty. It
* wakes-up the corresponding bdi thread which should then take care of the