From: Stefan Roesch <shr@devkernel.io> mainline inclusion from mainline-v6.2-rc1 commit bca52dcbadc583f4db6435599c44a79f97293f06 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 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: 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> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- mm/backing-dev.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index b3595a3b06b2..984df664b967 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -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, -- 2.39.2