Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1040087AbdDUNjz (ORCPT ); Fri, 21 Apr 2017 09:39:55 -0400 Received: from mail.kernel.org ([198.145.29.136]:48778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1039828AbdDUNjw (ORCPT ); Fri, 21 Apr 2017 09:39:52 -0400 Date: Fri, 21 Apr 2017 09:39:48 -0400 From: Steven Rostedt To: luca abeni Cc: Juri Lelli , linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Claudio Scordino , Tommaso Cucinotta , Daniel Bristot de Oliveira , Mathieu Poirier Subject: Re: [PATCH] sched/deadline: fix switching to -deadline Message-ID: <20170421093948.14c7b5d8@gandalf.local.home> In-Reply-To: <20170421115421.5d51a12b@nowhere> References: <1492716656-5362-1-git-send-email-luca.abeni@santannapisa.it> <20170421093926.GQ23862@e106622-lin> <20170421114240.0ef43522@nowhere> <20170421115421.5d51a12b@nowhere> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; 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 Content-Length: 1332 Lines: 34 On Fri, 21 Apr 2017 11:54:21 +0200 luca abeni wrote: > On Fri, 21 Apr 2017 11:42:40 +0200 > luca abeni wrote: > [...] > > > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > > > index a2ce590..ec53d24 100644 > > > > --- a/kernel/sched/deadline.c > > > > +++ b/kernel/sched/deadline.c > > > > @@ -950,6 +950,10 @@ enqueue_dl_entity(struct sched_dl_entity > > > > *dl_se, update_dl_entity(dl_se, pi_se); > > > > else if (flags & ENQUEUE_REPLENISH) > > > > replenish_dl_entity(dl_se, pi_se); > > > > + else if ((flags & ENQUEUE_RESTORE) && > > > > > > Not sure I understand how this works. AFAICT we are doing > > > __sched_setscheduler() when we want to catch the case of a new > > > dl_entity (SCHED_{OTHER,FIFO} -> SCHED_DEADLINE}, but queue_flags > > > (which are passed to enqueue_task()) don't seem to have > > > ENQUEUE_RESTORE set? > > > > I was under the impression sched_setscheduler() sets > > ENQUEUE_RESTORE... > > __sched_setscheduler() sets queue_flags to DEQUEUE_SAVE, which matches > ENQUEUE_RESTORE (see comments in sched/sched.h), so things should work > correctly, right? I was tripping over this too, but missed the comments in sched/sched.h. Probably want to stick a comment about this in here as well. -- Steve