From 4e230b406eda9bdf7f8a71e2cc3df18a824abcb0 Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Fri, 18 Nov 2022 16:52:10 -0800 Subject: mm: add bdi_set_max_ratio_no_scale() function 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. Link: https://lkml.kernel.org/r/20221119005215.3052436-16-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: Chris Mason Cc: Jens Axboe Signed-off-by: Andrew Morton --- 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); -- cgit