From 70ed28b92a786f44750ab64117b03d126dd14656 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 19 Nov 2008 14:38:39 +0100 Subject: [PATCH] block: leave the request timeout timer running even on an empty list For sync IO, we'll often do them serialized. This means we'll be touching the queue timer for every IO, as opposed to only occasionally like we do for queued IO. Instead of deleting the timer when the last request is removed, just let continue running. If a new request comes up soon we then don't have to readd the timer again. If no new requests arrive, the timer will expire without side effect later. This improves high iops sync IO by ~1%. Signed-off-by: Jens Axboe --- block/blk-core.c | 1 + block/blk-timeout.c | 4 ---- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 561e8a1b43a4..243d18b4ceb0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -404,6 +404,7 @@ EXPORT_SYMBOL(blk_stop_queue); void blk_sync_queue(struct request_queue *q) { del_timer_sync(&q->unplug_timer); + del_timer_sync(&q->timeout); kblockd_flush_work(&q->unplug_work); } EXPORT_SYMBOL(blk_sync_queue); diff --git a/block/blk-timeout.c b/block/blk-timeout.c index 99c3efc706b7..a09535377a94 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -73,11 +73,7 @@ ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr, */ void blk_delete_timer(struct request *req) { - struct request_queue *q = req->q; - list_del_init(&req->timeout_list); - if (list_empty(&q->timeout_list)) - del_timer(&q->timeout); } static void blk_rq_timed_out(struct request *req) -- 2.20.1