Badness in as_completed_request

Badness in as_completed_request

[Aaron Lehmann]

I've been seeing this about every day for the past month or so, while
tracking 2.6.0-test*. Usually by the time I feel like reporting it I'm
a few revisions behind and decide to upgrade before complaining about
it. Now I'm running -test9 and it still happens. This happens every
few day or so under normal load and every few minutes under high I/O
load. I'm running an x86 system with a 3ware RAID5:

Badness in as_completed_request at drivers/block/as-iosched.c:919
Call Trace:
 [<c021675d>] as_completed_request+0x1ad/0x1e0
 [<c020f84f>] elv_completed_request+0x1f/0x30
 [<c0211a4c>] __blk_put_request+0x3c/0xc0
 [<c0212902>] end_that_request_last+0x52/0xa0
 [<c0238b72>] scsi_end_request+0xb2/0xe0
 [<c0238f0b>] scsi_io_completion+0x1bb/0x470
 [<c02437ea>] sd_rw_intr+0x5a/0x1e0
 [<c02351db>] scsi_finish_command+0x7b/0xc0
 [<c011feeb>] update_wall_time+0xb/0x40
 [<c02350ee>] scsi_softirq+0xae/0xe0
 [<c011c250>] do_softirq+0x90/0xa0
 [<c010ab05>] do_IRQ+0xc5/0xe0
 [<c0105000>] _stext+0x0/0x30
 [<c01090a8>] common_interrupt+0x18/0x20
 [<c0105000>] _stext+0x0/0x30
 [<c0106e13>] default_idle+0x23/0x30
 [<c0106e7c>] cpu_idle+0x2c/0x40
 [<c035c69f>] start_kernel+0x13f/0x150
 [<c035c430>] unknown_bootoption+0x0/0x100

Re: Badness in as_completed_request

[Nick Piggin]

[-- Attachment #1: Type: text/plain, Size: 655 bytes --]

   

Aaron Lehmann wrote:

>I've been seeing this about every day for the past month or so, while
>tracking 2.6.0-test*. Usually by the time I feel like reporting it I'm
>a few revisions behind and decide to upgrade before complaining about
>it. Now I'm running -test9 and it still happens. This happens every
>few day or so under normal load and every few minutes under high I/O
>load. I'm running an x86 system with a 3ware RAID5:
>
>Badness in as_completed_request at drivers/block/as-iosched.c:919
>

This warning is harmless. Here is a patch against 2.6.0-test9-mm2.
Please test that kernel as it has a few other important as-iosched
fixes. Thanks.


[-- Attachment #2: as-warn-fix.patch --]
[-- Type: text/plain, Size: 591 bytes --]

 linux-2.6-npiggin/drivers/block/as-iosched.c |    2 --
 1 files changed, 2 deletions(-)

diff -puN drivers/block/as-iosched.c~as-warn-fix drivers/block/as-iosched.c
--- linux-2.6/drivers/block/as-iosched.c~as-warn-fix	2003-11-05 20:16:42.000000000 +1100
+++ linux-2.6-npiggin/drivers/block/as-iosched.c	2003-11-05 20:16:58.000000000 +1100
@@ -965,8 +965,6 @@ static void as_completed_request(request
 		return;
 
 	if (ad->changed_batch && ad->nr_dispatched == 1) {
-		WARN_ON(ad->batch_data_dir == arq->is_sync);
-
 		kblockd_schedule_work(&ad->antic_work);
 		ad->changed_batch = 0;
 

_