From: Jens Axboe <axboe@kernel.dk>
To: Tejun Heo <tj@kernel.org>
Cc: Hugh Dickins <hughd@google.com>,
Shaohua Li <shaohua.li@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH block/for-3.3/core] block: an exiting task should be allowed to create io_context
Date: Tue, 03 Jan 2012 21:20:44 +0100 [thread overview]
Message-ID: <4F03631C.8080501@kernel.dk> (raw)
In-Reply-To: <20120103200906.GG31746@google.com>
On 2012-01-03 21:09, Tejun Heo wrote:
> On Tue, Jan 03, 2012 at 09:59:22AM -0800, Tejun Heo wrote:
>> That should have been service tree. I couldn't find more missing
>> removals other than the one Shaohua's patch already fixed. Close
>> cooperator selection in cfq_select_queue() seems suspicious tho. I
>> can't see what prevents it from returning an empty coopeator cfqq.
>> I'm trying to verify whether that's the case. Will update when I know
>> more.
>
> While testing, found another bug.
>
> Redzone: 0x9f911029d74e35b/0x9f911029d74e35b.
> Last user: [<ffffffff813a82ee>](cfq_put_queue+0x7e/0xd0)
> 070: e8 32 ab 1d 00 88 ff ff e8 32 ab 1d 00 88 ff ff .2.......2......
> Prev obj: start=ffff88001dab3178, len=232
> Redzone: 0x9f911029d74e35b/0x9f911029d74e35b.
> Last user: [<ffffffff813a82ee>](cfq_put_queue+0x7e/0xd0)
> 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> Next obj: start=ffff88001dab3378, len=232
> Redzone: 0xd84156c5635688c0/0xd84156c5635688c0.
> Last user: [<ffffffff813a8e53>](cfq_get_queue+0x153/0x670)
> 000: 02 00 00 00 21 01 00 00 e0 c9 b1 1d 00 88 ff ff ....!...........
> 010: 89 96 ae 18 00 88 ff ff 00 00 00 00 00 00 00 00 ................
>
> The field at 0x70 which is being updated after being freed is
> cfqq->fifo. Interestingly, it didn't lead to any visible failure.
That's pretty odd. Given Hughs report as well, it sure does sound like
we now have some life time issues with cfqq's.
--
Jens Axboe
next prev parent reply other threads:[~2012-01-03 20:21 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-21 6:47 linux-next: Tree for Dec 21 Stephen Rothwell
2011-12-21 20:11 ` linux-next: Tree for Dec 21 (xen) Randy Dunlap
2011-12-21 19:30 ` Konrad Rzeszutek Wilk
2011-12-21 20:32 ` [PATCH] usb: fix renesas mod_gadget printk format warning Randy Dunlap
2011-12-21 21:16 ` Felipe Balbi
2011-12-21 22:19 ` Randy Dunlap
2011-12-21 21:24 ` Greg KH
2011-12-21 23:15 ` linux-next: Tree for Dec 21 Andrew Morton
2011-12-22 23:08 ` Andrew Morton
2011-12-22 23:20 ` Tejun Heo
2011-12-22 23:24 ` Andrew Morton
2011-12-22 23:38 ` Tejun Heo
2011-12-22 23:44 ` Andrew Morton
2011-12-22 23:46 ` Tejun Heo
2011-12-23 0:42 ` Tejun Heo
2011-12-24 5:13 ` Hugh Dickins
2011-12-25 1:02 ` [PATCH block/for-3.3/core] block: an exiting task should be allowed to create io_context Tejun Heo
2011-12-25 13:29 ` Jens Axboe
2011-12-27 22:07 ` Andrew Morton
2011-12-28 8:33 ` Hugh Dickins
2011-12-28 16:48 ` Tejun Heo
2011-12-28 17:50 ` Hugh Dickins
2011-12-28 17:55 ` Tejun Heo
2011-12-28 21:19 ` Tejun Heo
2012-01-03 17:35 ` Tejun Heo
2012-01-03 17:59 ` Tejun Heo
2012-01-03 20:09 ` Tejun Heo
2012-01-03 20:20 ` Jens Axboe [this message]
2012-01-03 22:13 ` Tejun Heo
2012-01-03 22:35 ` Tejun Heo
2012-01-05 1:24 ` Tejun Heo
2012-01-05 18:36 ` Hugh Dickins
2012-01-05 18:38 ` Tejun Heo
2012-01-06 2:17 ` [PATCH block:for-3.3/core] cfq: merged request shouldn't jump to a different cfqq Tejun Heo
2012-01-06 2:36 ` Tejun Heo
2012-01-06 3:14 ` Shaohua Li
2012-01-06 3:04 ` Tejun Heo
2012-01-06 3:30 ` Tejun Heo
2012-01-06 3:52 ` [PATCH block:for-3.3/core] block: disable ELEVATOR_INSERT_SORT_MERGE Tejun Heo
2012-01-06 4:19 ` Shaohua Li
2012-01-06 4:38 ` Tejun Heo
2012-01-06 8:15 ` Shaohua Li
2012-01-06 15:34 ` Tejun Heo
2012-01-06 3:34 ` [PATCH block:for-3.3/core] cfq: merged request shouldn't jump to a different cfqq Shaohua Li
2012-01-06 3:22 ` Tejun Heo
2012-01-06 4:15 ` Shaohua Li
2012-01-06 4:40 ` Tejun Heo
2012-01-06 2:47 ` Shaohua Li
2011-12-25 16:08 ` linux-next: Tree for Dec 21 Sedat Dilek
2011-12-25 23:55 ` Stephen Rothwell
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