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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 7460CC433ED for ; Fri, 16 Apr 2021 15:54:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A388611C2 for ; Fri, 16 Apr 2021 15:54:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236349AbhDPPy0 (ORCPT ); Fri, 16 Apr 2021 11:54:26 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:58184 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235689AbhDPPyH (ORCPT ); Fri, 16 Apr 2021 11:54:07 -0400 Date: Fri, 16 Apr 2021 15:53:40 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1618588421; 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=Lnu4T3cswxls+tJVsMJI6VS7beKHORnpxNYvU6mtNig=; b=GTwS/cWuFDwUPxiOVbxciaIYGmTUFgY5o29Ku9KAJN23bgRGCU8Piw68y7hHVcG//pLO+K q+G/LqQWFdewxQOLDJt8TorxvNGXFXcKd3FdQPt7v/MT1Nh6+d+wCbWY4hIuKVrLVG70YK yLUL1oIrj7GSDN+P3t/AqwEuusQHTzkAfUP6GnK3jIIJyS7cM/RO5HSN3yujeimPJGJxfj JcunWhioYcviUVkOpq0czMkudaSdljrByiV7DQ1qNNiz5jg5SYxjBJSHcfddlbdoQM/Q5H MmMh94uAZpX8Kr+bKAj/pYeGdO2sOUYd52bHk9bnWcOzArqw3klX79cDiowOJA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1618588421; 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=Lnu4T3cswxls+tJVsMJI6VS7beKHORnpxNYvU6mtNig=; b=8bpS5M7My6Od2n5ZkxomTWXhtZcKpd+N1RKfkSNeDrPlJFynZ1GBS3rkX1wyI0uKQe1Cx0 pa5V1xt6fOwwAWAw== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched,fair: Alternative sched_slice() Cc: "Peter Zijlstra (Intel)" , Valentin Schneider , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210412102001.611897312@infradead.org> References: <20210412102001.611897312@infradead.org> MIME-Version: 1.0 Message-ID: <161858842081.29796.1137333756957597015.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: 0c2de3f054a59f15e01804b75a04355c48de628c Gitweb: https://git.kernel.org/tip/0c2de3f054a59f15e01804b75a04355c48de628c Author: Peter Zijlstra AuthorDate: Thu, 25 Mar 2021 13:44:46 +01:00 Committer: Peter Zijlstra CommitterDate: Fri, 16 Apr 2021 17:06:35 +02:00 sched,fair: Alternative sched_slice() The current sched_slice() seems to have issues; there's two possible things that could be improved: - the 'nr_running' used for __sched_period() is daft when cgroups are considered. Using the RQ wide h_nr_running seems like a much more consistent number. - (esp) cgroups can slice it real fine, which makes for easy over-scheduling, ensure min_gran is what the name says. Signed-off-by: Peter Zijlstra (Intel) Tested-by: Valentin Schneider Link: https://lkml.kernel.org/r/20210412102001.611897312@infradead.org --- kernel/sched/fair.c | 12 +++++++++++- kernel/sched/features.h | 3 +++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b3ea14c..49636a4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -687,7 +687,13 @@ static u64 __sched_period(unsigned long nr_running) */ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq); + unsigned int nr_running = cfs_rq->nr_running; + u64 slice; + + if (sched_feat(ALT_PERIOD)) + nr_running = rq_of(cfs_rq)->cfs.h_nr_running; + + slice = __sched_period(nr_running + !se->on_rq); for_each_sched_entity(se) { struct load_weight *load; @@ -704,6 +710,10 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) } slice = __calc_delta(slice, se->load.weight, load); } + + if (sched_feat(BASE_SLICE)) + slice = max(slice, (u64)sysctl_sched_min_granularity); + return slice; } diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 422fa68..011c5ec 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -90,3 +90,6 @@ SCHED_FEAT(WA_BIAS, true) */ SCHED_FEAT(UTIL_EST, true) SCHED_FEAT(UTIL_EST_FASTUP, true) + +SCHED_FEAT(ALT_PERIOD, true) +SCHED_FEAT(BASE_SLICE, true)