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 86686C433F5 for ; Tue, 5 Oct 2021 14:12:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 707886113A for ; Tue, 5 Oct 2021 14:12:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235625AbhJEOOC (ORCPT ); Tue, 5 Oct 2021 10:14:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235216AbhJEONv (ORCPT ); Tue, 5 Oct 2021 10:13:51 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54944C061749; Tue, 5 Oct 2021 07:12:00 -0700 (PDT) Date: Tue, 05 Oct 2021 14:11:58 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1633443119; 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=MO4ONO4/LvRT6SbTELfO2gK+gVyae+STqHWpSU6IN5E=; b=yBDHtQ01zPMfvmLL/R+4pr6HvHF7guYPuygT/sJyyO+KD2wbqVjYOWLBjr8dtTf3GpO/ar 8ttufmhVLRXN6HeY0d7jVylpGeiJ3nltkyoc0yJeALJwpFWJa1fBqD08n9b+TdU3oXr1pm Wq09RNYBgBU6ZBEGXQieAUanYwJL69htn7vOwLDCu2zsB8bn1gCheMqKdY4Ujy4Fkch6pf 8C2agUa6G27zhZXYHUrG2ZG7WTvtCWBt479k5J/PjoKm9ryqLU34f8CAZsgiEAam3p8zNM eNoQ6eAvQ9XzPOcG2G2LxnEas6F2S6oIr9XwS0c2vt99Ki1fhUxz1+eJ38dKsw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1633443119; 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=MO4ONO4/LvRT6SbTELfO2gK+gVyae+STqHWpSU6IN5E=; b=zoBz6Zc2W6IBRfzkksPV6dvRehdPx6XumVtCsxN+9Fm3uN776elCD+21y8gqUo5c4Q1S+a SVEnX9PHiZMFyNDQ== 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: <163344311816.25758.1473259863674435692.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: 691925f3ddccea832cf2d162dc277d2623a816e3 Gitweb: https://git.kernel.org/tip/691925f3ddccea832cf2d162dc277d2623a816e3 Author: Thomas Gleixner AuthorDate: Tue, 28 Sep 2021 14:24:25 +02:00 Committer: Peter Zijlstra CommitterDate: Tue, 05 Oct 2021 15:52:11 +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 9eaeba6..749284f 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.