From 573412b29586e58477adb70e022193a337763319 Mon Sep 17 00:00:00 2001 From: Corrado Zoccolo Date: Sun, 6 Dec 2009 11:48:52 +0100 Subject: [PATCH] cfq-iosched: reduce write depth only if sync was delayed The introduction of ramp-up formula for async queue depths has slowed down dirty page reclaim, by reducing async write performance. This patch makes sure the formula kicks in only when sync request was recently delayed. Signed-off-by: Corrado Zoccolo Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index cfb0b2f5f63d..5009af490a0c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -283,7 +283,7 @@ struct cfq_data { */ struct cfq_queue oom_cfqq; - unsigned long last_end_sync_rq; + unsigned long last_delayed_sync; /* List of cfq groups being managed on this device*/ struct hlist_head cfqg_list; @@ -2264,7 +2264,7 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) * based on the last sync IO we serviced */ if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { - unsigned long last_sync = jiffies - cfqd->last_end_sync_rq; + unsigned long last_sync = jiffies - cfqd->last_delayed_sync; unsigned int depth; depth = last_sync / cfqd->cfq_slice[1]; @@ -3273,7 +3273,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) if (sync) { RQ_CIC(rq)->last_end_request = now; - cfqd->last_end_sync_rq = now; + if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) + cfqd->last_delayed_sync = now; } /* @@ -3711,7 +3712,7 @@ static void *cfq_init_queue(struct request_queue *q) cfqd->cfq_latency = 1; cfqd->cfq_group_isolation = 0; cfqd->hw_tag = -1; - cfqd->last_end_sync_rq = jiffies; + cfqd->last_delayed_sync = jiffies - HZ; INIT_RCU_HEAD(&cfqd->rcu); return cfqd; } -- 2.20.1