Commit 68a0b1c6 authored by Stefan Roesch's avatar Stefan Roesch Committed by Yifan Qiao
Browse files

mm: add bdi_get_min_bytes() function 

mainline inclusion
from mainline-v6.2-rc1
commit 712c00d6
category: feature
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAN96I

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=712c00d66a342a3ed375df41c3df7d3d2abad2c0

--------------------------------

This adds a function to return the specified value for min_bytes. It
converts the stored min_ratio of the bdi to the corresponding bytes
value. This is an approximation as it is based on the value that is
returned by global_dirty_limits(), which can change. The returned
value can be different than the value when the min_bytes value was set.

Link: https://lkml.kernel.org/r/20221119005215.3052436-11-shr@devkernel.io


Signed-off-by: default avatarStefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent 61914d59

include/linux/backing-dev.h

+1 −0
Original line number Diff line number Diff line
@@ -107,6 +107,7 @@ static inline unsigned long wb_stat_error(void) 
/* BDI ratio is expressed as part per 1000000 for finer granularity. */

#define BDI_RATIO_SCALE 10000



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);

mm/page-writeback.c

+5 −0
Original line number Diff line number Diff line
@@ -773,6 +773,11 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio) 
}

EXPORT_SYMBOL(bdi_set_max_ratio);



u64 bdi_get_min_bytes(struct backing_dev_info *bdi)

{

	return bdi_get_bytes(bdi->min_ratio);

}



u64 bdi_get_max_bytes(struct backing_dev_info *bdi)

{

	return bdi_get_bytes(bdi->max_ratio);