Commit d72b73e0 authored by Stefan Roesch's avatar Stefan Roesch Committed by Yifan Qiao
Browse files

mm: add /sys/class/bdi/<bdi>/max_ratio_fine knob 

mainline inclusion
from mainline-v6.2-rc1
commit bca52dcb
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/?id=bca52dcbadc583f4db6435599c44a79f97293f06

--------------------------------

This adds the max_ratio_fine knob. The knob specifies the values not
based on 1 of 100, but instead 1 per million.

Link: https://lkml.kernel.org/r/20221119005215.3052436-17-shr@devkernel.io


Signed-off-by: default avatarStefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent c4c8ed23

mm/backing-dev.c

+20 −0
Original line number Diff line number Diff line
@@ -197,6 +197,25 @@ static ssize_t max_ratio_store(struct device *dev, 
}

BDI_SHOW(max_ratio, bdi->max_ratio / BDI_RATIO_SCALE)



static ssize_t max_ratio_fine_store(struct device *dev,

		struct device_attribute *attr, const char *buf, size_t count)

{

	struct backing_dev_info *bdi = dev_get_drvdata(dev);

	unsigned int ratio;

	ssize_t ret;



	ret = kstrtouint(buf, 10, &ratio);

	if (ret < 0)

		return ret;



	ret = bdi_set_max_ratio_no_scale(bdi, ratio);

	if (!ret)

		ret = count;



	return ret;

}

BDI_SHOW(max_ratio_fine, bdi->max_ratio)



static ssize_t min_bytes_show(struct device *dev,

			      struct device_attribute *attr,

			      char *buf)
@@ -295,6 +314,7 @@ static struct attribute *bdi_dev_attrs[] = { 
	&dev_attr_read_ahead_kb.attr,

	&dev_attr_min_ratio.attr,

	&dev_attr_max_ratio.attr,

	&dev_attr_max_ratio_fine.attr,

	&dev_attr_min_bytes.attr,

	&dev_attr_max_bytes.attr,

	&dev_attr_stable_pages_required.attr,