From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E836EC7618F for ; Fri, 26 Jul 2019 20:01:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBC0D22BE8 for ; Fri, 26 Jul 2019 20:01:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387673AbfGZUB6 (ORCPT ); Fri, 26 Jul 2019 16:01:58 -0400 Received: from mail.sssup.it ([193.205.80.98]:21994 "EHLO mail.santannapisa.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387532AbfGZUB5 (ORCPT ); Fri, 26 Jul 2019 16:01:57 -0400 Received: from [151.41.39.6] (account l.abeni@santannapisa.it HELO sweethome) by santannapisa.it (CommuniGate Pro SMTP 6.1.11) with ESMTPSA id 141127218; Fri, 26 Jul 2019 22:01:55 +0200 Date: Fri, 26 Jul 2019 22:01:49 +0200 From: luca abeni To: Peter Zijlstra Cc: mingo@kernel.org, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, bristot@redhat.com, balsini@android.com, dvyukov@google.com, tglx@linutronix.de, vpillai@digitalocean.com, rostedt@goodmis.org Subject: Re: [RFC][PATCH 00/13] SCHED_DEADLINE server infrastructure Message-ID: <20190726220149.6f05f8df@sweethome> In-Reply-To: <20190726145409.947503076@infradead.org> References: <20190726145409.947503076@infradead.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, On Fri, 26 Jul 2019 16:54:09 +0200 Peter Zijlstra wrote: > Hi, > > So recently syzcaller ran into the big deadline/period issue (again), > and I figured I should at least propose a patch that puts limits on > that -- see Patch 1. > > During that discussion; SCHED_OTHER servers got mentioned (also > again), and I figured I should have a poke at that too. So I took > some inspiration from patches Alessio Balsini send a while back and > cobbled something together for that too. I think Patch 1 is a very good idea! The server patches look interesting (and they seem to be much simpler than our patchset :). I need to have a better look at them, but this seems to be very promising. Thanks, Luca > > Included are also a bunch of patches I did for core scheduling (2-8), > which I'm probably going to just merge as they're generic cleanups. > They're included here because they make pick_next_task() simpler and > thereby thinking about the nested pick_next_task() logic inherent in > servers was less of a head-ache. (I think it can work fine without > them, but its easier with them on) > > Anyway; after it all compiled it booted a kvm image all the way to > userspace on the first run, so clearly this code isn't to be trusted > at all. > > There's still lots of missing bits and pieces -- like changelogs and > the fair server isn't configurable or hooked into the bandwidth > accounting, but the foundation is there I think. > > Enjoy! >