From: Stefan Roesch <shr@devkernel.io> mainline inclusion from mainline-v6.2-rc1 commit 54790f30fea74247e2f38b4a632ee3dc2fe42d86 category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAN96I Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This documents the new /sys/class/bdi/<bdi>/max_ratio_fine knob. [akpm@linux-foundation.org: fix htmldocs warnings] Link: https://lkml.kernel.org/r/20221119005215.3052436-18-shr@devkernel.io Signed-off-by: Stefan Roesch <shr@devkernel.io> Cc: Chris Mason <clm@meta.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: Documentation/ABI/testing/sysfs-class-bdi [Adapt to same document style.] Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- Documentation/ABI/testing/sysfs-class-bdi | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 0cf0c0ffff60..3b779e95f243 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -48,6 +48,15 @@ max_ratio (read-write) mount that is prone to get stuck, or a FUSE mount which cannot be trusted to play fair. +max_ratio_fine (read-write) + + Allows limiting a particular device to use not more than the + given value of the write-back cache. The value is given as part + of 1 million. This is useful in situations where we want to avoid + one device taking all or most of the write-back cache. For example + in case of an NFS mount that is prone to get stuck, or a FUSE mount + which cannot be trusted to play fair. + min_bytes (read-write) Under normal circumstances each device is given a part of the -- 2.39.2