From 316d315bffa4026f28085f6b24ebcebede370ac7 Mon Sep 17 00:00:00 2001 From: Nikanth Karthikesan Date: Tue, 6 Oct 2009 20:16:55 +0200 Subject: block: Seperate read and write statistics of in_flight requests v2 Commit a9327cac440be4d8333bba975cbbf76045096275 added seperate read and write statistics of in_flight requests. And exported the number of read and write requests in progress seperately through sysfs. But Corrado Zoccolo reported getting strange output from "iostat -kx 2". Global values for service time and utilization were garbage. For interval values, utilization was always 100%, and service time is higher than normal. So this was reverted by commit 0f78ab9899e9d6acb09d5465def618704255963b The problem was in part_round_stats_single(), I missed the following: if (now == part->stamp) return; - if (part->in_flight) { + if (part_in_flight(part)) { __part_stat_add(cpu, part, time_in_queue, part_in_flight(part) * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); With this chunk included, the reported regression gets fixed. Signed-off-by: Nikanth Karthikesan -- Signed-off-by: Jens Axboe --- block/blk-merge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/blk-merge.c') diff --git a/block/blk-merge.c b/block/blk-merge.c index b0de8574fdc8..99cb5cf1f447 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -351,7 +351,7 @@ static void blk_account_io_merge(struct request *req) part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req)); part_round_stats(cpu, part); - part_dec_in_flight(part); + part_dec_in_flight(part, rq_data_dir(req)); part_stat_unlock(); } -- cgit v1.2.3