linux-kernel - Re: [RFC PATCH 1/2] block: strict rq

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]

Message-ID: <4E2B151C.6080900@fusionio.com>
Date:	Sat, 23 Jul 2011 20:38:20 +0200
From:	Jens Axboe <jaxboe@...ionio.com>
To:	Christoph Hellwig <hch@...radead.org>
CC:	Dan Williams <dan.j.williams@...el.com>,
	Roland Dreier <roland@...estorage.com>,
	Dave Jiang <dave.jiang@...el.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>
Subject: Re: [RFC PATCH 1/2] block: strict rq_affinity

On 2011-07-23 03:46, Christoph Hellwig wrote:
> On Fri, Jul 22, 2011 at 01:59:39PM -0700, Dan Williams wrote:
>> Some storage controllers benefit from completions always being steered
>> to the strict requester cpu rather than the looser "per-socket" steering
>> that blk_cpu_to_group() attempts by default.
> 
> Isn't this actually dependent on the cpu, and not the storage
> controller?

It is, it's completely indendent of the controller used. Perhaps some
drivers could have a very heavy end io completion handling causing the
problem to become larger, but in general it's an artifact of the CPU and
not the controller.

-- 
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/