From 15853af9f07673680439b224519c692f1352b959 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 10 Nov 2005 08:52:05 +0100 Subject: [BLOCK] Implement elv_drain_elevator for improved switch error detection This patch adds request_queue->nr_sorted which keeps the number of requests in the iosched and implement elv_drain_elevator which performs forced dispatching. elv_drain_elevator checks whether iosched actually dispatches all requests it has and prints error message if it doesn't. As buggy forced dispatching can result in wrong barrier operations, I think this extra check is worthwhile. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 025a7f084dbd..a33a31e71bbc 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -406,6 +406,7 @@ struct request_queue atomic_t refcnt; + unsigned int nr_sorted; unsigned int in_flight; /* @@ -631,6 +632,7 @@ static inline void elv_dispatch_add_tail(struct request_queue *q, { if (q->last_merge == rq) q->last_merge = NULL; + q->nr_sorted--; q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; -- cgit v1.2.3