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| author |   Dennis Zhou <dennis@kernel.org> | 2018-12-05 12:10:34 -0500 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2018-12-07 22:26:37 -0700 |
| commit | fd42df305f804ddc0d5ac028e944784283b2f92d (patch) | |
| tree | f10e4821b3dca25647f1eaf401b8f4529d0d2ade /Documentation/admin-guide | |
| parent | blkcg: associate a blkg for pages being evicted by swap (diff) | |
| download | linux-dev-fd42df305f804ddc0d5ac028e944784283b2f92d.tar.xz linux-dev-fd42df305f804ddc0d5ac028e944784283b2f92d.zip | |
blkcg: associate writeback bios with a blkg
One of the goals of this series is to remove a separate reference to
the css of the bio. This can and should be accessed via bio_blkcg(). In
this patch, wbc_init_bio() now requires a bio to have a device
associated with it.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 476722b7b636..baf19bf28385 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1879,8 +1879,10 @@ following two functions. wbc_init_bio(@wbc, @bio) Should be called for each bio carrying writeback data and - associates the bio with the inode's owner cgroup. Can be - called anytime between bio allocation and submission. + associates the bio with the inode's owner cgroup and the + corresponding request queue. This must be called after + a queue (device) has been associated with the bio and + before submission. wbc_account_io(@wbc, @page, @bytes) Should be called for each data segment being written out. @@ -1899,7 +1901,7 @@ the configuration, the bio may be executed at a lower priority and if the writeback session is holding shared resources, e.g. a journal entry, may lead to priority inversion. There is no one easy solution for the problem. Filesystems can try to work around specific problem -cases by skipping wbc_init_bio() or using bio_associate_blkcg() +cases by skipping wbc_init_bio() and using bio_associate_blkg() directly. |