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| author | Jan Kara <jack@suse.cz> | 2022-06-23 10:51:44 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-24 18:39:31 -0600 |
| commit | ea6813be07dcdc072aa9ad18099115a74cecb5e1 (patch) | |
| tree | f4e94a1779139dc9f57684fbce5fc29b76541c2b /mm/page-writeback.c | |
| parent | f6b543fd03d347e8bf245cee4f2d54eb6ffd8fcb (diff) | |
| download | lwn-ea6813be07dcdc072aa9ad18099115a74cecb5e1.tar.gz lwn-ea6813be07dcdc072aa9ad18099115a74cecb5e1.zip | |
mm: Move starting of background writeback into the main balancing loop
We start background writeback if we are over background threshold after
exiting the main loop in balance_dirty_pages(). This may result in
basing the decision on already stale values (we may have slept for
significant amount of time) and it is also inconvenient for refactoring
needed for async dirty throttling. Move the check into the main waiting
loop.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Stefan Roesch <shr@fb.com>
Link: https://lore.kernel.org/r/20220623175157.1715274-2-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 55c2776ae699..e59c523aed1a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1628,6 +1628,19 @@ static void balance_dirty_pages(struct bdi_writeback *wb, } /* + * In laptop mode, we wait until hitting the higher threshold + * before starting background writeout, and then write out all + * the way down to the lower threshold. So slow writers cause + * minimal disk activity. + * + * In normal mode, we start background writeout at the lower + * background_thresh, to keep the amount of dirty memory low. + */ + if (!laptop_mode && nr_reclaimable > gdtc->bg_thresh && + !writeback_in_progress(wb)) + wb_start_background_writeback(wb); + + /* * Throttle it only when the background writeback cannot * catch-up. This avoids (excessively) small writeouts * when the wb limits are ramping up in case of !strictlimit. @@ -1657,6 +1670,7 @@ free_running: break; } + /* Start writeback even when in laptop mode */ if (unlikely(!writeback_in_progress(wb))) wb_start_background_writeback(wb); @@ -1823,23 +1837,6 @@ pause: if (!dirty_exceeded && wb->dirty_exceeded) wb->dirty_exceeded = 0; - - if (writeback_in_progress(wb)) - return; - - /* - * In laptop mode, we wait until hitting the higher threshold before - * starting background writeout, and then write out all the way down - * to the lower threshold. So slow writers cause minimal disk activity. - * - * In normal mode, we start background writeout at the lower - * background_thresh, to keep the amount of dirty memory low. - */ - if (laptop_mode) - return; - - if (nr_reclaimable > gdtc->bg_thresh) - wb_start_background_writeback(wb); } static DEFINE_PER_CPU(int, bdp_ratelimits); |