From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbcBOQWH (ORCPT ); Mon, 15 Feb 2016 11:22:07 -0500 Received: from smtprelay0057.hostedemail.com ([216.40.44.57]:43987 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751024AbcBOQWF (ORCPT ); Mon, 15 Feb 2016 11:22:05 -0500 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3870:3871:3872:3873:3874:4250:4321:5007:6261:7875:7903:10004:10400:10848:10967:11026:11232:11658:11914:12517:12519:12555:12663:12740:13069:13161:13181:13229:13311:13357:14096:14097:14659:21080:21324:30054:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:5,LUA_SUMMARY:none X-HE-Tag: thing02_2ef7703da1a5f X-Filterd-Recvd-Size: 2584 Date: Mon, 15 Feb 2016 11:22:01 -0500 From: Steven Rostedt To: Juri Lelli Cc: LKML , Juri Lelli , Peter Zijlstra , Ingo Molnar , Clark Williams , Daniel Bristot de Oliveira , John Kacur Subject: Re: [PATCH] sched/deadline: Always calculate end of period on sched_yield() Message-ID: <20160215112201.774a2c0d@gandalf.local.home> In-Reply-To: <20160215101824.GD22643@pablo> References: <20160212181020.7dbaf326@gandalf.local.home> <20160215101824.GD22643@pablo> X-Mailer: Claws Mail 3.13.1 (GTK+ 2.24.29; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 Feb 2016 10:18:24 +0000 Juri Lelli wrote: > > Signed-off-by: Steven Rostedt > > --- > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > index cd64c979d0e1..1dd180cda574 100644 > > --- a/kernel/sched/deadline.c > > +++ b/kernel/sched/deadline.c > > @@ -735,7 +735,7 @@ static void update_curr_dl(struct rq *rq) > > * approach need further study. > > */ > > delta_exec = rq_clock_task(rq) - curr->se.exec_start; > > - if (unlikely((s64)delta_exec <= 0)) > > + if (unlikely((s64)delta_exec <= 0 && !dl_se->dl_yielded)) > > return; > > > > This looks good to me. Do you think we could also skip some of the > following updates/accounting in this case? Not sure we win anything by > doing that, though. > Well, I would say we get this patch in first and think about other updates second. This fixes one bug, might as well pull it in. I'm now looking into a second bug. I'm getting: RT throttling activated and DL replenish lagged to much messages, back to back, when I'm only using 50% of the band width. Looks to be a leak of how much is being used. The big issue here is that these messages kill the test due to the latency caused to perform the printk(). After the messages are splatted out (they only print once per boot), the tests run fine again. IOW, there seems to be no real issue of something doing too much bandwidth. I get this with or without this current patch. -- Steve