This introduces bdi_set_min_ratio_no_scale(). It uses the max
granularity for the ratio. This function by the new sysfs knob
min_ratio_fine.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/backing-dev.h | 1 +
mm/page-writeback.c | 7 +++++++
2 files changed, 8 insertions(+)
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index d9acbb22ff25..fbad4fcd408e 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_min_ratio_no_scale(struct backing_dev_info *bdi, unsigned int min_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);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f44ade72966c..ad608ef2a243 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -690,6 +690,8 @@ static int __bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ra
unsigned int delta;
int ret = 0;
+ if (min_ratio > 100 * BDI_RATIO_SCALE)
+ return -EINVAL;
min_ratio *= BDI_RATIO_SCALE;
spin_lock_bh(&bdi_lock);
@@ -734,6 +736,11 @@ static int __bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ra
return ret;
}
+int bdi_set_min_ratio_no_scale(struct backing_dev_info *bdi, unsigned int min_ratio)
+{
+ return __bdi_set_min_ratio(bdi, min_ratio);
+}
+
int bdi_set_max_ratio_no_scale(struct backing_dev_info *bdi, unsigned int max_ratio)
{
return __bdi_set_max_ratio(bdi, max_ratio);
--
2.30.2
