diff options
| author | Stefan Roesch <shr@devkernel.io> | 2022-11-19 03:52:02 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-12-01 02:59:04 +0300 |
| commit | 1bf27e98d26d1e62166a456ef17460be085cbe0b (patch) | |
| tree | 3234f844db72d37499676681018b3ee62430b91a | |
| parent | efc3e6ad53ea14225b434fddca261c9a1c56c707 (diff) | |
| download | linux-1bf27e98d26d1e62166a456ef17460be085cbe0b.tar.xz | |
mm: add bdi_set_max_bytes() function
This introduces the bdi_set_max_bytes() function. The max_bytes function
does not store the max_bytes value. Instead it converts the max_bytes
value into the corresponding ratio value.
Link: https://lkml.kernel.org/r/20221119005215.3052436-8-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>
| -rw-r--r-- | include/linux/backing-dev.h | 1 | ||||
| -rw-r--r-- | mm/page-writeback.c | 37 |
2 files changed, 38 insertions, 0 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 473686c32775..ea6c993433d5 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -108,6 +108,7 @@ static inline unsigned long wb_stat_error(void) 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_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 e74ef596dc27..20ae9adeb22f 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -13,6 +13,7 @@ */ #include <linux/kernel.h> +#include <linux/math64.h> #include <linux/export.h> #include <linux/spinlock.h> #include <linux/fs.h> @@ -650,6 +651,28 @@ void wb_domain_exit(struct wb_domain *dom) */ static unsigned int bdi_min_ratio; +static int bdi_check_pages_limit(unsigned long pages) +{ + unsigned long max_dirty_pages = global_dirtyable_memory(); + + if (pages > max_dirty_pages) + return -EINVAL; + + return 0; +} + +static unsigned long bdi_ratio_from_pages(unsigned long pages) +{ + unsigned long background_thresh; + unsigned long dirty_thresh; + unsigned long ratio; + + global_dirty_limits(&background_thresh, &dirty_thresh); + ratio = div64_u64(pages * 100ULL * BDI_RATIO_SCALE, dirty_thresh); + + return ratio; +} + static u64 bdi_get_bytes(unsigned int ratio) { unsigned long background_thresh; @@ -722,6 +745,20 @@ u64 bdi_get_max_bytes(struct backing_dev_info *bdi) return bdi_get_bytes(bdi->max_ratio); } +int bdi_set_max_bytes(struct backing_dev_info *bdi, u64 max_bytes) +{ + int ret; + unsigned long pages = max_bytes >> PAGE_SHIFT; + unsigned long max_ratio; + + ret = bdi_check_pages_limit(pages); + if (ret) + return ret; + + max_ratio = bdi_ratio_from_pages(pages); + return __bdi_set_max_ratio(bdi, max_ratio); +} + int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit) { if (strict_limit > 1) |