From: Stefan Roesch <shr@devkernel.io> mainline inclusion from mainline-v6.2-rc1 commit 16b837eb84e6948f92411eb32e97a05f89733ddc category: bugfix 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>/strict_limit knob. Link: https://lkml.kernel.org/r/20221119005215.3052436-4-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> Conflict: Documentation/ABI/testing/sysfs-class-bdi [Context differences] Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- Documentation/ABI/testing/sysfs-class-bdi | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 5402bd74ba43..9982fd0439ae 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -48,6 +48,17 @@ max_ratio (read-write) mount that is prone to get stuck, or a FUSE mount which cannot be trusted to play fair. + (read-write) +What: /sys/class/bdi/<bdi>/strict_limit +Date: October 2022 +Contact: Stefan Roesch <shr@devkernel.io> +Description: + Forces per-BDI checks for the share of given device in the write-back + cache even before the global background dirty limit is reached. This + is useful in situations where the global limit is much higher than + affordable for given relatively slow (or untrusted) device. Turning + strictlimit on has no visible effect if max_ratio is equal to 100%. + stable_pages_required (read-only) If set, the backing device requires that all pages comprising a write -- 2.39.2