diff options
Diffstat (limited to 'drivers/md/bcache/writeback.c')
| -rw-r--r-- | drivers/md/bcache/writeback.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 1696b212ec4e..73f0efac2b9f 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -17,6 +17,15 @@ #include <linux/sched/clock.h> #include <trace/events/bcache.h> +static void update_gc_after_writeback(struct cache_set *c) +{ + if (c->gc_after_writeback != (BCH_ENABLE_AUTO_GC) || + c->gc_stats.in_use < BCH_AUTO_GC_DIRTY_THRESHOLD) + return; + + c->gc_after_writeback |= BCH_DO_AUTO_GC; +} + /* Rate limiting */ static uint64_t __calc_target_rate(struct cached_dev *dc) { @@ -191,6 +200,7 @@ static void update_writeback_rate(struct work_struct *work) if (!set_at_max_writeback_rate(c, dc)) { down_read(&dc->writeback_lock); __update_writeback_rate(dc); + update_gc_after_writeback(c); up_read(&dc->writeback_lock); } } @@ -689,6 +699,23 @@ static int bch_writeback_thread(void *arg) up_write(&dc->writeback_lock); break; } + + /* + * When dirty data rate is high (e.g. 50%+), there might + * be heavy buckets fragmentation after writeback + * finished, which hurts following write performance. + * If users really care about write performance they + * may set BCH_ENABLE_AUTO_GC via sysfs, then when + * BCH_DO_AUTO_GC is set, garbage collection thread + * will be wake up here. After moving gc, the shrunk + * btree and discarded free buckets SSD space may be + * helpful for following write requests. + */ + if (c->gc_after_writeback == + (BCH_ENABLE_AUTO_GC|BCH_DO_AUTO_GC)) { + c->gc_after_writeback &= ~BCH_DO_AUTO_GC; + force_wake_up_gc(c); + } } up_write(&dc->writeback_lock); |