Re: 2.6.5-rc1-mm2 very slow

[Jens Axboe <axboe@suse.de>]

On Fri, Mar 19 2004, Holger Kiehl wrote:
> Hello
> 
> I am testing 2.6.5-rc1-mm2 and find it very slow when I do a bonnie
> test, also the system itself feels very sluggish. Looking at dmesg
> I get the following:
> 
>    Badness in elv_remove_request at drivers/block/elevator.c:249
>    Call Trace:
>     [<c028b28f>] elv_remove_request+0x8d/0x8f
>     [<c02b6a4e>] scsi_request_fn+0x289/0x333
>     [<c028b174>] elv_next_request+0x3d/0xcb
>     [<c028c8da>] generic_unplug_device+0x43/0x45

Does it still complain with this patch?

--- drivers/block/elevator.c~	2004-03-18 10:56:34.494431670 +0100
+++ drivers/block/elevator.c	2004-03-18 11:05:00.115063157 +0100
@@ -153,7 +153,7 @@
 	 * it already went through dequeue, we need to decrement the
 	 * in_flight count again
 	 */
-	if (blk_rq_started(rq)) {
+	if (blk_account_rq(rq)) {
 		WARN_ON(q->in_flight == 0);
 		q->in_flight--;
 	}
@@ -244,7 +244,7 @@
 	 * driver has seen (REQ_STARTED set), to avoid false accounting
 	 * for request-request merges
 	 */
-	if (blk_rq_started(rq)) {
+	if (blk_account_rq(rq)) {
 		q->in_flight++;
 		WARN_ON(q->in_flight > 2 * q->nr_requests);
 	}
@@ -341,7 +341,7 @@
 	/*
 	 * request is released from the driver, io must be done
 	 */
-	if (blk_rq_started(rq)) {
+	if (blk_account_rq(rq)) {
 		WARN_ON(q->in_flight == 0);
 		q->in_flight--;
 	}
--- include/linux/blkdev.h~	2004-03-18 11:03:59.431584757 +0100
+++ include/linux/blkdev.h	2004-03-18 11:05:16.980250506 +0100
@@ -381,6 +381,8 @@
 #define blk_noretry_request(rq)	((rq)->flags & REQ_FAILFAST)
 #define blk_rq_started(rq)	((rq)->flags & REQ_STARTED)
 
+#define blk_account_rq(rq)	(blk_rq_started(rq) && blk_fs_request(rq))
+
 #define blk_pm_suspend_request(rq)	((rq)->flags & REQ_PM_SUSPEND)
 #define blk_pm_resume_request(rq)	((rq)->flags & REQ_PM_RESUME)
 #define blk_pm_request(rq)	\


-- 
Jens Axboe