This introduces bdi_set_max_ratio_no_scale(). It uses the max
granularity for the ratio. This function by the new sysfs knob
max_ratio_fine.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/backing-dev.h | 1 +
mm/page-writeback.c | 11 ++++++++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 572669758c7f..d9acbb22ff25 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -109,6 +109,7 @@ u64 bdi_get_min_bytes(struct backing_dev_info *bdi);
u64 bdi_get_max_bytes(struct backing_dev_info *bdi);
int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
+int bdi_set_max_ratio_no_scale(struct backing_dev_info *bdi, unsigned int max_ratio);
int bdi_set_min_bytes(struct backing_dev_info *bdi, u64 min_bytes);
int bdi_set_max_bytes(struct backing_dev_info *bdi, u64 max_bytes);
int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 3d151e7a9b6c..f44ade72966c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -719,6 +719,9 @@ static int __bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ra
{
int ret = 0;
+ if (max_ratio > 100 * BDI_RATIO_SCALE)
+ return -EINVAL;
+
spin_lock_bh(&bdi_lock);
if (bdi->min_ratio > max_ratio) {
ret = -EINVAL;
@@ -731,6 +734,11 @@ static int __bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ra
return ret;
}
+int bdi_set_max_ratio_no_scale(struct backing_dev_info *bdi, unsigned int max_ratio)
+{
+ return __bdi_set_max_ratio(bdi, max_ratio);
+}
+
int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
{
return __bdi_set_min_ratio(bdi, min_ratio * BDI_RATIO_SCALE);
@@ -738,9 +746,6 @@ int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio)
{
- if (max_ratio > 100)
- return -EINVAL;
-
return __bdi_set_max_ratio(bdi, max_ratio * BDI_RATIO_SCALE);
}
EXPORT_SYMBOL(bdi_set_max_ratio);
--
2.30.2
