From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbbDCQYi (ORCPT ); Fri, 3 Apr 2015 12:24:38 -0400 Received: from mail-am1on0100.outbound.protection.outlook.com ([157.56.112.100]:8274 "EHLO emea01-am1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752429AbbDCQYd (ORCPT ); Fri, 3 Apr 2015 12:24:33 -0400 Authentication-Results: spf=fail (sender IP is 12.216.194.146) smtp.mailfrom=ezchip.com; ezchip.com; dkim=none (message not signed) header.d=none; From: To: "Peter Zijlstra (Intel)" , Frederic Weisbecker , "Paul E. McKenney" , "Rafael J. Wysocki" , Martin Schwidefsky , Ingo Molnar , CC: Chris Metcalf Subject: [PATCH 2/2] nohz: make nohz_full imply isolcpus Date: Fri, 3 Apr 2015 12:24:08 -0400 Message-ID: <1428078248-5425-2-git-send-email-cmetcalf@ezchip.com> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1428078248-5425-1-git-send-email-cmetcalf@ezchip.com> References: <1428078248-5425-1-git-send-email-cmetcalf@ezchip.com> X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:12.216.194.146;CTRY:US;IPV:NLI;EFV:NLI;BMV:1;SFV:NSPM;SFS:(10009020)(6009001)(339900001)(189002)(199003)(77156002)(62966003)(42186005)(50226001)(85426001)(48376002)(36756003)(50986999)(575784001)(19580395003)(86152002)(6806004)(76176999)(87936001)(19580405001)(2950100001)(105606002)(86362001)(47776003)(106466001)(92566002)(33646002)(50466002)(46102003)(104016003)(229853001);DIR:OUT;SFP:1101;SCL:1;SRVR:AM2PR02MB0770;H:ld-1.internal.tilera.com;FPR:;SPF:Fail;MLV:sfv;MX:1;A:1;LANG:en; MIME-Version: 1.0 Content-Type: text/plain X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0770;UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0852; X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(5002010)(5005006);SRVR:AM2PR02MB0770;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0770; X-Forefront-PRVS: 05352A48BE X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Apr 2015 16:24:28.3061 (UTC) X-MS-Exchange-CrossTenant-Id: 0fc16e0a-3cd3-4092-8b2f-0a42cff122c3 X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=0fc16e0a-3cd3-4092-8b2f-0a42cff122c3;Ip=[12.216.194.146];Helo=[ld-1.internal.tilera.com] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM2PR02MB0770 X-OriginatorOrg: ezchip.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chris Metcalf It's not clear that nohz_full is useful without isolcpus also set, since otherwise the scheduler has to run periodically to try to determine whether to steal work from other cores. Signed-off-by: Chris Metcalf --- I am puzzled why this has not been done before, so I suspect there is some argument against it that I am missing, but I wasn't able to turn anything up by searching LKML. kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f0f831e8a345..275f12c608f2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6836,6 +6836,7 @@ static int init_sched_domains(const struct cpumask *cpu_map) doms_cur = alloc_sched_domains(ndoms_cur); if (!doms_cur) doms_cur = &fallback_doms; + tick_nohz_full_set_cpus(cpu_isolated_map); cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); err = build_sched_domains(doms_cur[0], NULL); register_sched_domain_sysctl(); -- 2.1.2