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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 1992EC10F13 for ; Thu, 11 Apr 2019 09:19:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D98E7217D4 for ; Thu, 11 Apr 2019 09:19:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y48faedk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726902AbfDKJTh (ORCPT ); Thu, 11 Apr 2019 05:19:37 -0400 Received: from merlin.infradead.org ([205.233.59.134]:33466 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbfDKJTh (ORCPT ); Thu, 11 Apr 2019 05:19:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9c60AGgd69b3Z99oQ5a0JMRXREkHX8NI6cxc0l0GOXI=; b=Y48faedkfUdflMG+gPyT0IboI lrDcdYMwCJ6pAMNBrfUx/nvyF6HXQBfEdIchz/j6+/prR4JCizpv+Tg5hhiaQ2fWF8U0bi6kG1Nir YGbHSGy/3mVUiHuRwi9qZeZ2B8Ca+cQ/O5ga8n0htZaiR/T1caCVVuVzefdB0pHn3BHHqHrMGalQP HaFDtDRTz/R+e50iwuqerPSC137mMJMbUKJGTsZ9fANiRb9IFOhDtUgnG7xZIzamzsR28MrbdlmcD qrARrHrcG1uPyccq93COE4RDRc7bj9FwisgzvtNSfAP+CZojU1WoSdyuaTpnxrAUuahyJiKjo+T28 vvc8kGlnQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEVrT-0000Ry-Gh; Thu, 11 Apr 2019 09:19:11 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 466D72029E070; Thu, 11 Apr 2019 11:19:10 +0200 (CEST) Date: Thu, 11 Apr 2019 11:19:10 +0200 From: Peter Zijlstra To: Aaron Lu Cc: Tim Chen , mingo@kernel.org, tglx@linutronix.de, pjt@google.com, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, subhra.mazumdar@oracle.com, fweisbec@gmail.com, keescook@chromium.org, kerrnel@google.com, Aubrey Li , Julien Desfossez Subject: Re: [RFC][PATCH 13/16] sched: Add core wide task selection and scheduling. Message-ID: <20190411091910.GF4038@hirez.programming.kicks-ass.net> References: <20190218165620.383905466@infradead.org> <20190218173514.667598558@infradead.org> <20190402064612.GA46500@aaronlu> <20190402082812.GJ12232@hirez.programming.kicks-ass.net> <20190405145530.GA453@aaronlu> <460ce6fb-6a40-4a72-47e8-cf9c7c409bef@linux.intel.com> <20190410043633.GA67532@aaronlu> <20190410144418.GH2490@worktop.programming.kicks-ass.net> <20190411030541.GA99895@aaronlu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190411030541.GA99895@aaronlu> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 11, 2019 at 11:05:41AM +0800, Aaron Lu wrote: > On Wed, Apr 10, 2019 at 04:44:18PM +0200, Peter Zijlstra wrote: > > When core_cookie==0 we shouldn't schedule the other siblings at all. > > Not even with another untagged task? > > I was thinking to leave host side tasks untagged, like kernel threads, > init and other system daemons or utilities etc., and tenant tasks tagged. > Then at least two untagged tasks can be scheduled on the same core. > > Kindly let me know if you see a problem with this. Let me clarify; when the rq->core->core_cookie == 0, each sibling should schedule independently. As Julien found, there were some issues here, but the intent was: core_cookie 0, independent scheduling core_cookie 0->n, core scheduling core_cookie n->0, one last core schedule to kick possibly forced idle siblings