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 30F0AC4332F for ; Thu, 28 Oct 2021 09:49:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12D0F60F9B for ; Thu, 28 Oct 2021 09:49:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229906AbhJ1JwB (ORCPT ); Thu, 28 Oct 2021 05:52:01 -0400 Received: from outbound-smtp22.blacknight.com ([81.17.249.190]:38621 "EHLO outbound-smtp22.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230301AbhJ1Jve (ORCPT ); Thu, 28 Oct 2021 05:51:34 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp22.blacknight.com (Postfix) with ESMTPS id 603C3BABC5 for ; Thu, 28 Oct 2021 10:48:45 +0100 (IST) Received: (qmail 22672 invoked from network); 28 Oct 2021 09:48:45 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPA; 28 Oct 2021 09:48:45 -0000 From: Mel Gorman To: Peter Zijlstra Cc: Ingo Molnar , Vincent Guittot , Valentin Schneider , Aubrey Li , Barry Song , Mike Galbraith , Srikar Dronamraju , LKML , Mel Gorman Subject: [PATCH v4 0/2] Reduce stacking and overscheduling Date: Thu, 28 Oct 2021 10:48:32 +0100 Message-Id: <20211028094834.1312-1-mgorman@techsingularity.net> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Also available at git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git sched-scalewakegran-v4r1 Changelog since v3 o No code changes, added some additional results to patch 1 These series tackles two problems. The first is that heavy wakers can stack an excessive number of tasks on the same CPU. The second is that tasks can overschedule when the task has not reached its minimum preemption granularity. The patches are independent but were discussed together in the thread https://lore.kernel.org/r/20210920142614.4891-1-mgorman@techsingularity.net so are presented together. With both patches on a zen3 machine hackbench-process-pipes 5.15.0-rc3 5.15.0-rc3 vanilla sched-scalewakegran-v3r2 Amean 1 0.3667 ( 0.00%) 0.3823 ( -4.27%) Amean 4 0.5343 ( 0.00%) 0.4867 ( 8.92%) Amean 7 0.5300 ( 0.00%) 0.5053 ( 4.65%) Amean 12 0.5737 ( 0.00%) 0.5450 ( 5.00%) Amean 21 0.6727 ( 0.00%) 0.6807 ( -1.19%) Amean 30 0.8583 ( 0.00%) 0.7107 * 17.20%* Amean 48 1.3977 ( 0.00%) 1.0447 * 25.26%* Amean 79 1.9790 ( 0.00%) 1.6033 * 18.98%* Amean 110 2.8020 ( 0.00%) 2.0763 * 25.90%* Amean 141 3.6683 ( 0.00%) 2.5313 * 31.00%* Amean 172 4.6687 ( 0.00%) 3.1163 * 33.25%* Amean 203 5.2183 ( 0.00%) 3.5560 * 31.86%* Amean 234 6.1077 ( 0.00%) 3.8913 * 36.29%* Amean 265 7.1313 ( 0.00%) 4.2293 * 40.69%* Amean 296 7.7557 ( 0.00%) 4.5357 * 41.52%* 5.15.0-rc3 5.15.0-rc3 vanilla sched-scalewakegran-v3r2 Duration User 2933.05 2034.17 Duration System 25652.83 17137.08 Duration Elapsed 162.50 120.25 kernel/sched/fair.c | 27 ++++++++++++++++++++++++--- kernel/sched/features.h | 2 ++ 2 files changed, 26 insertions(+), 3 deletions(-) -- 2.31.1