Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755104AbZKCU2d (ORCPT ); Tue, 3 Nov 2009 15:28:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754583AbZKCU2c (ORCPT ); Tue, 3 Nov 2009 15:28:32 -0500 Received: from [95.166.99.235] ([95.166.99.235]:53483 "EHLO kernel.dk" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754129AbZKCU2c (ORCPT ); Tue, 3 Nov 2009 15:28:32 -0500 Date: Tue, 3 Nov 2009 21:28:36 +0100 From: Jens Axboe To: Jeff Moyer Cc: Corrado Zoccolo , Linux-Kernel Subject: Re: Fwd: [PATCH 0/5] cfq-iosched: improve latency for no-idle queues (v3) Message-ID: <20091103202836.GM8742@kernel.dk> References: <4e5e476b0910271124r2cf9f9c0l83fdc59b50619202@mail.gmail.com> <4e5e476b0911030042q5963718aj5875c542e6f6cc40@mail.gmail.com> <4e5e476b0911030719m425c208cg311f44a91fad8342@mail.gmail.com> <4e5e476b0911031035l7caffcb7n36b6eddd399864e7@mail.gmail.com> <20091103201802.GL8742@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2708 Lines: 82 On Tue, Nov 03 2009, Jeff Moyer wrote: > Jens Axboe writes: > > > Since for-linus contains conflicting changes, can you and Jeff please > > double check that everything is still in order? The interesting bit here > > is the merge with for-2.6.33 and the coop limit from Shaohua Li. I did > > the straight forward merge, but we likely just need to drop that logic > > since the coop concept is radically different given that we merge and > > break queues in for-2.6.33. > > Yeah, since I changed the meaning of the cfqq_coop flag, a lot of those > tests are just plain wrong. Let me play with it and I'll send you an > incremental patch in a bit. Thanks, here's what I have. It's basically a revert of the commit in question. diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index b700f41..4ab240c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -253,7 +253,6 @@ enum cfqq_state_flags { CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ CFQ_CFQQ_FLAG_sync, /* synchronous queue */ CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ - CFQ_CFQQ_FLAG_coop_preempt, /* coop preempt */ }; #define CFQ_CFQQ_FNS(name) \ @@ -280,7 +279,6 @@ CFQ_CFQQ_FNS(prio_changed); CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); CFQ_CFQQ_FNS(coop); -CFQ_CFQQ_FNS(coop_preempt); #undef CFQ_CFQQ_FNS #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ @@ -1070,16 +1068,9 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - if (!cfqq) { + if (!cfqq) cfqq = cfq_get_next_queue(cfqd); - if (cfqq && !cfq_cfqq_coop_preempt(cfqq)) - cfq_clear_cfqq_coop(cfqq); - } - - if (cfqq) - cfq_clear_cfqq_coop_preempt(cfqq); - __cfq_set_active_queue(cfqd, cfqq); return cfqq; } @@ -2433,16 +2424,8 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, * if this request is as-good as one we would expect from the * current cfqq, let it preempt */ - if (cfq_rq_close(cfqd, cfqq, rq) && (!cfq_cfqq_coop(new_cfqq) || - cfqd->busy_queues == 1)) { - /* - * Mark new queue coop_preempt, so its coop flag will not be - * cleared when new queue gets scheduled at the very first time - */ - cfq_mark_cfqq_coop_preempt(new_cfqq); - cfq_mark_cfqq_coop(new_cfqq); + if (cfq_rq_close(cfqd, cfqq, rq)) return true; - } return false; } -- Jens Axboe -- 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/