Commit 9450ff8d authored by Stefan Roesch's avatar Stefan Roesch Committed by Yifan Qiao
Browse files

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

mainline inclusion
from mainline-v6.2-rc1
commit ad3e6dab
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=ad3e6dabf6f7d9ffd68eb711191ef16cdbdd25f0

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

This adds the min_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/20221119005215.3052436-20-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 aa121733

mm/backing-dev.c

+20 −0
Original line number Diff line number Diff line
@@ -178,6 +178,25 @@ static ssize_t min_ratio_store(struct device *dev, 
}

BDI_SHOW(min_ratio, bdi->min_ratio / BDI_RATIO_SCALE)



static ssize_t min_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_min_ratio_no_scale(bdi, ratio);

	if (!ret)

		ret = count;



	return ret;

}

BDI_SHOW(min_ratio_fine, bdi->min_ratio)



static ssize_t max_ratio_store(struct device *dev,

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

{
@@ -313,6 +332,7 @@ static DEVICE_ATTR_RW(strict_limit); 
static struct attribute *bdi_dev_attrs[] = {

	&dev_attr_read_ahead_kb.attr,

	&dev_attr_min_ratio.attr,

	&dev_attr_min_ratio_fine.attr,

	&dev_attr_max_ratio.attr,

	&dev_attr_max_ratio_fine.attr,

	&dev_attr_min_bytes.attr,