Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932675AbbFIK1C (ORCPT ); Tue, 9 Jun 2015 06:27:02 -0400 Received: from stringer.orebokech.com ([212.83.175.182]:57840 "EHLO stringer.orebokech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbbFIK04 (ORCPT ); Tue, 9 Jun 2015 06:26:56 -0400 X-Greylist: delayed 502 seconds by postgrey-1.27 at vger.kernel.org; Tue, 09 Jun 2015 06:26:55 EDT From: Romain Francoise To: Tahsin Erdogan Cc: Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: [PATCH] block: Make CFQ default to IOPS mode on SSDs Organization: orebokech dot com References: <1432068921-17184-1-git-send-email-tahsin@google.com> Date: Tue, 09 Jun 2015 12:18:32 +0200 In-Reply-To: <1432068921-17184-1-git-send-email-tahsin@google.com> (Tahsin Erdogan's message of "Tue, 19 May 2015 13:55:21 -0700") Message-ID: <873821kww7.fsf@orebokech.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 27 Hi, On Tue, May 19, 2015 at 01:55:21PM -0700, Tahsin Erdogan wrote: > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -4460,7 +4460,7 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) > cfqd->cfq_slice[1] = cfq_slice_sync; > cfqd->cfq_target_latency = cfq_target_latency; > cfqd->cfq_slice_async_rq = cfq_slice_async_rq; > - cfqd->cfq_slice_idle = cfq_slice_idle; > + cfqd->cfq_slice_idle = blk_queue_nonrot(q) ? 0 : cfq_slice_idle; > cfqd->cfq_group_idle = cfq_group_idle; > cfqd->cfq_latency = 1; > cfqd->hw_tag = -1; Did you test this patch with regular AHCI SSD devices? Applying it on top of v4.1-rc7 makes no difference, slice_idle is still initialized to 8 in my setup, while rotational is 0. Isn't the elevator initialized long before the non-rotational flag is actually set on the device (which probably happens after it's probed on the scsi bus)? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/