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=-7.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 08A08C433ED for ; Thu, 20 May 2021 18:03:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE91C60FF1 for ; Thu, 20 May 2021 18:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234935AbhETSEw (ORCPT ); Thu, 20 May 2021 14:04:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:54902 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231648AbhETSEq (ORCPT ); Thu, 20 May 2021 14:04:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2210360FF1; Thu, 20 May 2021 18:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621533805; bh=qBshlKu2zd7WKE8/gF2eNvUhAIN7rsAOhrY25OU7S/0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pXsFzpYQH2wzpNYeAwSJlXYpYiHKtKc+CdDvA4bSzh/IBqfPEkK9c8ErOviUmMNob nhHnGmlpuHoyOG0HP0UGRxMO435sjFN5rnFTJryVuOdwXyzSFc7pohl6V7/BWvg4l1 8Jc5Ay5roGEd+cZA2hQ/unaY39j5wQBuTtBAZpEY6fiaCbny+y4v6jotinasOo00lU 85z63cYie5xvNH+VYAmj4nX8K83rN5cvwKAx8ZspukzuFyvO3swRFO64uvZle5Dupv tpB1S5HHW0gM72DHn2gzZPRdG0wXoblF8rFG6/yF39V67hzD0BiJs5ExCxVgNsC2a1 wYh45KMfEhhjA== Date: Thu, 20 May 2021 19:03:18 +0100 From: Will Deacon To: Dietmar Eggemann Cc: Daniel Bristot de Oliveira , Quentin Perret , Juri Lelli , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Tejun Heo , Johannes Weiner , Ingo Molnar , Vincent Guittot , "Rafael J. Wysocki" , kernel-team@android.com Subject: Re: [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Message-ID: <20210520180318.GB10523@willie-the-truck> References: <20210518105951.GC7770@willie-the-truck> <20210520101640.GA10065@willie-the-truck> <0dbdfe1e-dede-d33d-ca89-768a1fa3c907@arm.com> <8bc24850-3a14-5dd2-fbc2-bf745616949f@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8bc24850-3a14-5dd2-fbc2-bf745616949f@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dietmar, On Thu, May 20, 2021 at 07:55:27PM +0200, Dietmar Eggemann wrote: > On 20/05/2021 18:00, Daniel Bristot de Oliveira wrote: > > On 5/20/21 5:06 PM, Dietmar Eggemann wrote: > >> (1) # chrt -d -T 5000000 -P 16666666 0 ./32bit_app > >> > >> (2) # ./32bit_app & > >> > >> # chrt -d -T 5000000 -P 16666666 -p 0 pid_of(32bit_app) > >> > >> > >> Wouldn't the behaviour of (1) and (2) be different w/o this patch? > >> > >> In (1) __sched_setscheduler() happens before execve so it operates on > >> p->cpus_ptr equal span. > >> > >> In (2) span != p->cpus_ptr so DL AC will fail. > >> > > > > As far as I got, the case (1) would be spitted in two steps: > > > > - __sched_setscheduler() will work, then > > - execv() would fail because (span != p->cpus_ptr) > > > > So... at the end, both (1) and (2) would result in a failure... > > > > am I missing something? > > Not sure. Reading this thread I was under the assumption that the only > change would be the drop of this patch. But I assume there is also this > 'if DL AC is on then let sched_setattr() fail for this 32bit task'. > > IMHO, the current patch-stack w/o this patch should let (1) succeed with > DL AC. That's what I'm proposing, yes, but others (including Daniel) prefer to fail the execve(). See my other reply just now for a summary [1]. Thanks! Will [1] https://lore.kernel.org/lkml/20210520180138.GA10523@willie-the-truck/T/#u 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=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 8860CC433B4 for ; Thu, 20 May 2021 18:05:28 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0AE9B6100A for ; Thu, 20 May 2021 18:05:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AE9B6100A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oCR9GKwLB+FVuDMSL4AmLBnB4ub6fjOakMXo5yr7180=; b=pHkxwc5ISk2Y6fAj9osZhMSZxc 26QWIsjvKu4VaxIWEeXi9onmtKBHUUaP5N4sRZvQYbIHN3tNcdRIeOIQi6D3Jxxa86/sPoqPgR+wc QjCtpGuItLEsbe4Spa4ch7Bs6DA9gDfzKwUjbLPaY8mYFGae9P59M7LyaS5jXo4qUFrtvpVvM5AUG 8Ny1ez4SrJ6MNoTAxW6vkWEOvsy45xoCmKc1ya8ysFF3CIsQqWDSkAb4ezcrpJeQzxYFvm7CEPk0n A/x8bZU+NPHYLfzmV/DS98G+b8CfkYfH0F6aqGyDyvmZmre5H8HA/5jjXpCGJBHnlakbyd314+MdC Gzxdx72A==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ljn19-002Clf-N2; Thu, 20 May 2021 18:03:32 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ljn16-002Cl5-Pp for linux-arm-kernel@desiato.infradead.org; Thu, 20 May 2021 18:03:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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; bh=EZT/oYzGIPjD0Ec1GHDPYz1E0gxA3xbQdNpGYayvCzQ=; b=UTVFFqZLK1ZH/dlFL4H2ZMovRW ij6cwM6+bTF3VomzQGnozSbCVztpp37HmDRLdfJAr/LVz97MRiDcapVIc7klaibcxMTZho+KIbhQ9 u50aEVQ0W2WloUAf7ddy/utCh9/8hnm7K7uRGC/Sn6sHfbjv6dlNfpvOO1twMSi0ZeBzbh/ob5ZoQ 6KLJHjYSKgvuBFm+OIk4nsa3tD8+O7k5E/rs1ihd0d4g9JDpDcHKLdp+rEtzlx4ZBss+FpzkNWRJJ 6SV6MjYfvz8lECPiU9K5m/DCnaiXNwNr+s8AZv+FQxV6xFqBAKMjvE8gmubu6dGq+TUw0GNbNR9Vp NtTKb7Sg==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1ljn13-00GYuE-Tj for linux-arm-kernel@lists.infradead.org; Thu, 20 May 2021 18:03:27 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2210360FF1; Thu, 20 May 2021 18:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621533805; bh=qBshlKu2zd7WKE8/gF2eNvUhAIN7rsAOhrY25OU7S/0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pXsFzpYQH2wzpNYeAwSJlXYpYiHKtKc+CdDvA4bSzh/IBqfPEkK9c8ErOviUmMNob nhHnGmlpuHoyOG0HP0UGRxMO435sjFN5rnFTJryVuOdwXyzSFc7pohl6V7/BWvg4l1 8Jc5Ay5roGEd+cZA2hQ/unaY39j5wQBuTtBAZpEY6fiaCbny+y4v6jotinasOo00lU 85z63cYie5xvNH+VYAmj4nX8K83rN5cvwKAx8ZspukzuFyvO3swRFO64uvZle5Dupv tpB1S5HHW0gM72DHn2gzZPRdG0wXoblF8rFG6/yF39V67hzD0BiJs5ExCxVgNsC2a1 wYh45KMfEhhjA== Date: Thu, 20 May 2021 19:03:18 +0100 From: Will Deacon To: Dietmar Eggemann Cc: Daniel Bristot de Oliveira , Quentin Perret , Juri Lelli , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Tejun Heo , Johannes Weiner , Ingo Molnar , Vincent Guittot , "Rafael J. Wysocki" , kernel-team@android.com Subject: Re: [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Message-ID: <20210520180318.GB10523@willie-the-truck> References: <20210518105951.GC7770@willie-the-truck> <20210520101640.GA10065@willie-the-truck> <0dbdfe1e-dede-d33d-ca89-768a1fa3c907@arm.com> <8bc24850-3a14-5dd2-fbc2-bf745616949f@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8bc24850-3a14-5dd2-fbc2-bf745616949f@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210520_110326_000976_324C00C4 X-CRM114-Status: GOOD ( 19.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Dietmar, On Thu, May 20, 2021 at 07:55:27PM +0200, Dietmar Eggemann wrote: > On 20/05/2021 18:00, Daniel Bristot de Oliveira wrote: > > On 5/20/21 5:06 PM, Dietmar Eggemann wrote: > >> (1) # chrt -d -T 5000000 -P 16666666 0 ./32bit_app > >> > >> (2) # ./32bit_app & > >> > >> # chrt -d -T 5000000 -P 16666666 -p 0 pid_of(32bit_app) > >> > >> > >> Wouldn't the behaviour of (1) and (2) be different w/o this patch? > >> > >> In (1) __sched_setscheduler() happens before execve so it operates on > >> p->cpus_ptr equal span. > >> > >> In (2) span != p->cpus_ptr so DL AC will fail. > >> > > > > As far as I got, the case (1) would be spitted in two steps: > > > > - __sched_setscheduler() will work, then > > - execv() would fail because (span != p->cpus_ptr) > > > > So... at the end, both (1) and (2) would result in a failure... > > > > am I missing something? > > Not sure. Reading this thread I was under the assumption that the only > change would be the drop of this patch. But I assume there is also this > 'if DL AC is on then let sched_setattr() fail for this 32bit task'. > > IMHO, the current patch-stack w/o this patch should let (1) succeed with > DL AC. That's what I'm proposing, yes, but others (including Daniel) prefer to fail the execve(). See my other reply just now for a summary [1]. Thanks! Will [1] https://lore.kernel.org/lkml/20210520180138.GA10523@willie-the-truck/T/#u _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel