Re: [RFC PATCH 1/2] block: strict rq_affinity

From: Jens Axboe
Date: Sat Jul 23 2011 - 14:41:51 EST

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@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at