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| author | Stefan Roesch <shr@devkernel.io> | 2022-11-18 16:52:00 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-30 15:59:04 -0800 |
| commit | 00df7d51263b46ed93f7572e2d09579746f7b1eb (patch) | |
| tree | f79ffb1660825cef999d7c22e3ef2ca76ec9824f /mm | |
| parent | ae82291e9ca47c3d6da6b77a00f427754aca413e (diff) | |
| download | linux-stable-00df7d51263b46ed93f7572e2d09579746f7b1eb.tar.gz linux-stable-00df7d51263b46ed93f7572e2d09579746f7b1eb.tar.bz2 linux-stable-00df7d51263b46ed93f7572e2d09579746f7b1eb.zip | |
mm: add bdi_get_max_bytes() function
This adds a function to return the specified value for max_bytes. It
converts the stored max_ratio of the bdi to the corresponding bytes
value. It introduces the bdi_get_bytes helper function to do the
conversion. This is an approximation as it is based on the value that is
returned by global_dirty_limits(), which can change. The helper function
will also be used by the min_bytes bdi knob.
Link: https://lkml.kernel.org/r/20221119005215.3052436-6-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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page-writeback.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index dd98b2654302..719404e0d03d 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -650,6 +650,18 @@ void wb_domain_exit(struct wb_domain *dom) */ static unsigned int bdi_min_ratio; +static u64 bdi_get_bytes(unsigned int ratio) +{ + unsigned long background_thresh; + unsigned long dirty_thresh; + u64 bytes; + + global_dirty_limits(&background_thresh, &dirty_thresh); + bytes = (dirty_thresh * PAGE_SIZE * ratio) / BDI_RATIO_SCALE / 100; + + return bytes; +} + int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio) { unsigned int delta; @@ -701,6 +713,11 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio) } EXPORT_SYMBOL(bdi_set_max_ratio); +u64 bdi_get_max_bytes(struct backing_dev_info *bdi) +{ + return bdi_get_bytes(bdi->max_ratio); +} + int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit) { if (strict_limit > 1) |