linux-kernel - Re: [PATCH 5/8] cfq-iosched: remove @gfp_mask from cfq_find_alloc

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

Date:	Tue, 09 Jun 2015 10:29:33 -0400
From:	Jeff Moyer <jmoyer@...hat.com>
To:	Tejun Heo <tj@...nel.org>
Cc:	axboe@...nel.dk, linux-kernel@...r.kernel.org,
	cgroups@...r.kernel.org, vgoyal@...hat.com,
	avanzini.arianna@...il.com
Subject: Re: [PATCH 5/8] cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue()

Tejun Heo <tj@...nel.org> writes:

> Hey, Jeff.
>
> On Mon, Jun 08, 2015 at 04:27:10PM -0400, Jeff Moyer wrote:
>> >> Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes
>> >> to its callers.  This simplifies the function quite a bit and will
>> >> help making async queues per-cfq_group.
>> >
>> > Sorry, I disagree with this patch.  You've changed it so that all cfqq
>> > allocations are GFP_ATOMIC, and most, if not all of them simply don't
>> > need to be.
>> 
>> It occurs to me that replacing GFP_ATOMIC with GFP_NOWAIT in your patch
>> would address my concerns, and patches 6-8 would apply almost as-is.
>> What do you think about that?
>
> Oh yeah, it's okay to fail these allocations under memory pressure.
> GFP_NOWAIT is the better pick here.  It's GFP_ATOMIC mostly due to
> historic copy&paste anyway.  I'll change them to GFP_NOWAIT.

OK.  Assuming that's the only change, you can go ahead and add my
Reviewed-by: Jeff Moyer <jmoyer@...hat.com> to the next iteration.

Thanks!
Jeff
--
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/