linux-kernel - Re: [PATCH 0/2] blk-throttle: Couple of cleanup and fixes for limit update code

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 7 Mar 2011 21:34:14 +0100
From:	Jens Axboe <jaxboe@...ionio.com>
To:	Vivek Goyal <vgoyal@...hat.com>
CC:	"oleg@...hat.com" <oleg@...hat.com>,
	"paulmck@...ux.vnet.ibm.com" <paulmck@...ux.vnet.ibm.com>,
	linux kernel mailing list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/2] blk-throttle: Couple of cleanup and fixes for limit
  update code

On 2011-03-07 21:29, Vivek Goyal wrote:
> On Mon, Mar 07, 2011 at 09:13:45PM +0100, Jens Axboe wrote:
>> On 2011-03-07 16:50, Vivek Goyal wrote:
>>> On Mon, Feb 21, 2011 at 06:42:48PM -0500, Vivek Goyal wrote:
>>>> Hi Jens,
>>>>
>>>> Couple of throttle fixes seem to have fallen through cracks.
>>>>
>>>> https://lkml.org/lkml/2010/12/15/331
>>>>
>>>> I am reposting it for inclusion. Please let me know if you have any concerns.
>>>> Oleg and Paul acked the patch in the past so I am retaining their Reviewed-by:
>>>> lines.
>>>>
>>>
>>> Hi Jens,
>>>
>>> Can you please apply following patches for 2.6.39. These are good for fixing
>>> couple of race conditions in block throttle code w.r.t limit updates.
>>> Please let me know if you have concernes with these patches.
>>
>> I have applied them now. 2/2 is a nice cleanup. But it does not apply
>> cleanly after the workqueue change we merged last week. I fixed it up
>> for you, manually applied hunk #5 and added the below diff. Please
>> inspect the end result. You should have rebased that patch.
> 
> Sorry, this patch was posted before workqueue change last week. I should
> have rebased and reposted it before pinging you again. Will take care of
> it next time onwards.
> 
>>
>> Also note that you seem to have a double xchg() in there, also added
>> from 2/2.
> 
> Actually one xchg is tracking per group limit changes (tg) and one xchg()
> it tracking overall limit change per queue (td), meaning if any of
> the group on this queue has changed the limit or not. That avoids
> traversal of list of all the groups if none of the group has changed
> the limit.

Irk, it's the tg and td looking too similar. It's indeed not a double
xhcg(), sorry for the noise.

-- 
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/