The patch titled Subject: mm: document /sys/class/bdi/<bdi>/max_bytes knob has been added to the -mm mm-unstable branch. Its filename is mm-document-sys-class-bdi-bdi-max_bytes-knob.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-document-sys-class-bdi-bdi-max_bytes-knob.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Stefan Roesch <shr@xxxxxxxxxxxx> Subject: mm: document /sys/class/bdi/<bdi>/max_bytes knob Date: Fri, 18 Nov 2022 16:52:04 -0800 This documents the new /sys/class/bdi/<bdi>/max_bytes knob. Link: https://lkml.kernel.org/r/20221119005215.3052436-10-shr@xxxxxxxxxxxx Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx> Cc: Chris Mason <clm@xxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/ABI/testing/sysfs-class-bdi | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/Documentation/ABI/testing/sysfs-class-bdi~mm-document-sys-class-bdi-bdi-max_bytes-knob +++ a/Documentation/ABI/testing/sysfs-class-bdi @@ -56,6 +56,20 @@ Description: be trusted to play fair. (read-write) + +What: /sys/class/bdi/<bdi>/max_bytes +Date: October 2022 +Contact: Stefan Roesch <shr@xxxxxxxxxxxx> +Description: + Allows limiting a particular device to use not more than the + given 'max_bytes' of the write-back cache. 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, a FUSE mount which cannot be + trusted to play fair, or a nbd device. + + (read-write) + What: /sys/class/bdi/<bdi>/strict_limit Date: October 2022 Contact: Stefan Roesch <shr@xxxxxxxxxxxx> _ Patches currently in -mm which might be from shr@xxxxxxxxxxxx are mm-add-bdi_set_strict_limit-function.patch mm-add-knob-sys-class-bdi-bdi-strict_limit.patch mm-document-sys-class-bdi-bdi-strict_limit-knob.patch mm-use-part-per-1000000-for-bdi-ratios.patch mm-add-bdi_get_max_bytes-function.patch mm-split-off-__bdi_set_max_ratio-function.patch mm-add-bdi_set_max_bytes-function.patch mm-add-knob-sys-class-bdi-bdi-max_bytes.patch mm-document-sys-class-bdi-bdi-max_bytes-knob.patch mm-add-bdi_get_min_bytes-function.patch mm-split-off-__bdi_set_min_ratio-function.patch mm-add-bdi_set_min_bytes-function.patch mm-add-sys-class-bdi-bdi-min_bytes-knob.patch mm-document-sys-class-bdi-bdi-min_bytes-knob.patch mm-add-bdi_set_max_ratio_no_scale-function.patch mm-add-sys-class-bdi-bdi-max_ratio_fine-knob.patch mm-document-sys-class-bdi-bdi-max_ratio_fine-knob.patch mm-add-bdi_set_min_ratio_no_scale-function.patch mm-add-sys-class-bdi-bdi-min_ratio_fine-knob.patch mm-document-sys-class-bdi-bdi-min_ratio_fine-knob.patch