[PATCH 2/9] blkcg, writeback: Add wbc->no_wbc_acct
From: Tejun Heo <tj@kernel.org>
Date: 2019-06-15 18:25:13
Also in:
linux-btrfs, lkml
Subsystem:
filesystems (vfs and infrastructure), page cache, the rest · Maintainers:
Alexander Viro, Christian Brauner, Matthew Wilcox, Jan Kara, Linus Torvalds
When writeback IOs are bounced through async layers, the IOs should only be accounted against the wbc from the original bdi writeback to avoid confusing cgroup inode ownership arbitration. Add wbc->no_wbc_acct to allow disabling wbc accounting. This will be used make btfs compression work well with cgroup IO control. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> --- fs/fs-writeback.c | 2 +- include/linux/writeback.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index c29cff345b1f..667ba07fffcd 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c@@ -724,7 +724,7 @@ void wbc_account_io(struct writeback_control *wbc, struct page *page, * behind a slow cgroup. Ultimately, we want pageout() to kick off * regular writeback instead of writing things out itself. */ - if (!wbc->wb) + if (!wbc->wb || wbc->no_wbc_acct) return; id = mem_cgroup_css_from_page(page)->id;
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 738a0c24874f..b8f5f000cde4 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h@@ -68,6 +68,7 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ + unsigned no_wbc_acct:1; /* skip wbc IO accounting */ #ifdef CONFIG_CGROUP_WRITEBACK struct bdi_writeback *wb; /* wb this writeback is issued under */ struct inode *inode; /* inode being written out */
--
2.17.1