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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10059C433F5 for ; Fri, 1 Oct 2021 15:06:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9F7961A40 for ; Fri, 1 Oct 2021 15:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354935AbhJAPIJ (ORCPT ); Fri, 1 Oct 2021 11:08:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354910AbhJAPHr (ORCPT ); Fri, 1 Oct 2021 11:07:47 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB170C0613EC; Fri, 1 Oct 2021 08:05:53 -0700 (PDT) Date: Fri, 01 Oct 2021 15:05:51 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1633100752; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zLrJ8oBhRoOGHAvO/vfr78vQiyZkSw3otCkPOsi1/nk=; b=vTfeMdoAshiQl7fPDlYkdwauNA9+QMynacCjOXLqgjB8Eh+pG6fb2zu+kzZE11+a33BXQp PSTeXXdmWqgGmn+VjxbB4JYvHIRd64OSkHgWekiHNx6HxR2bmcWtA91P6ublpzFKyQF8Kh cXxO9rd+eF8UdBnaHKe+I0sAyGrwOTLpSsXrCNUe/Pd1Th1ij1ASET3U2RKup28T1MsndQ HCmUyTnj7WIYlGqrQeEieIVAzNwrjbipuli36LiUUq7IFjnrifYhxt9VFxzVWoQw4HqXAE yHWgxCWEumTxrdQkpMiuo0/spqLyQJdNMS0PmXTPwFkGgVNGb6fK87jMvDlhwA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1633100752; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zLrJ8oBhRoOGHAvO/vfr78vQiyZkSw3otCkPOsi1/nk=; b=KWbael7laDvQI3FC2VQu4tGZedL3NJPM/w+AZDrgvptkAXjYFVvm2ELGCYcbezzO4WTQ9j FbBG7Uoj7CzeIhCA== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched: Limit the number of task migrations per batch on RT Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210928122411.425097596@linutronix.de> References: <20210928122411.425097596@linutronix.de> MIME-Version: 1.0 Message-ID: <163310075145.25758.10821100401474045244.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 92add3a897e9e923acde0f2c5e69705818076d69 Gitweb: https://git.kernel.org/tip/92add3a897e9e923acde0f2c5e69705818076d69 Author: Thomas Gleixner AuthorDate: Tue, 28 Sep 2021 14:24:25 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 01 Oct 2021 13:58:07 +02:00 sched: Limit the number of task migrations per batch on RT Batched task migrations are a source for large latencies as they keep the scheduler from running while processing the migrations. Limit the batch size to 8 instead of 32 when running on a RT enabled kernel. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210928122411.425097596@linutronix.de --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bb70a07..8d844d0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -74,7 +74,11 @@ __read_mostly int sysctl_resched_latency_warn_once = 1; * Number of tasks to iterate in a single balance run. * Limited because this is done with IRQs disabled. */ +#ifdef CONFIG_PREEMPT_RT +const_debug unsigned int sysctl_sched_nr_migrate = 8; +#else const_debug unsigned int sysctl_sched_nr_migrate = 32; +#endif /* * period over which we measure -rt task CPU usage in us.