Received: by 2002:a25:ad19:0:0:0:0:0 with SMTP id y25csp495842ybi; Fri, 26 Jul 2019 13:27:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqwuLrFI0KFpQmIyllAWLcn43nCgj27CwImu+tcZq6jQv3CoW/IEN8olTO87K78MOPBfHQA7 X-Received: by 2002:aa7:8a92:: with SMTP id a18mr24465657pfc.216.1564172846626; Fri, 26 Jul 2019 13:27:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564172846; cv=none; d=google.com; s=arc-20160816; b=z/Es58CZw0af+qMmivHHl8MaqCgnvVVRQ/idzKCMj6kvQNVaqn7NNmlaOfN8QTSBBi OTvJ2KUTVAuAQTBwd4DwMIvZwRFYihrDy6vILoqCy/kgWnxu0BkBLNX2CVS8JbbY50vi MMfafCRKc8RwuzyWrybJrA7Ae2x+UYUV6xl8MJX48MSCYweXHrJwM8unGR8T02SNZM20 8bZsyUa2sh4p9FFQxfcF154+CupqhczwFclNotmTfe4qrUyvHZ2ZHADMJtlOB5tsRjWB AbVJXHd2Gc76etEigBbEwMH9DHl2bj16VlgO74Ig3jBvFY/zKAmw1KK6hGHYt2XKZx5c cJZA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=ZcQSdcVMOAYYxzzTBxKWqc6CusWmG8lI7CM5G4AZTso=; b=ENeWH87ggj4On+Lit+GQvSmZCmKvNAXUgQWVLHpIYsasofGou2kfiY5VgtP1StqyvP k6o7K9NiMa2WyA3KitTSfv0Xu4hFpyzORUSofkZnYcR16IPKnf/FZne8GjG1AZ9BiRi5 4QirLoyWggd9YYY6PTqdzlOUJwItKGM21pp832V3z+7Gq16qaLeXwxvFtyFAqYW8z88A 0hFnDF34tGc2Ea3HYA9B8PTIDPIKnbR4zEu852J5MQ9IsiexhQxfu1DJpIzgVIx0K6S9 4DfAclLCLQroQi/kh8ypwQ1xDEiO6NhOoIqX+E6IchgsL7+pjsZoxjnnWKo5amuyCO0z 37xg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b18si18667149plz.389.2019.07.26.13.27.11; Fri, 26 Jul 2019 13:27:26 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387665AbfGZUB6 (ORCPT + 99 others); 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! >