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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B27ADC25B47 for ; Wed, 25 Oct 2023 15:12:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 50D6B6B0341; Wed, 25 Oct 2023 11:12:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4BD036B0342; Wed, 25 Oct 2023 11:12:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3AC876B0343; Wed, 25 Oct 2023 11:12:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 2AEEF6B0341 for ; Wed, 25 Oct 2023 11:12:58 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 03C17120718 for ; Wed, 25 Oct 2023 15:12:57 +0000 (UTC) X-FDA: 81384326436.16.A37E34E Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf18.hostedemail.com (Postfix) with ESMTP id 31E621C0032 for ; Wed, 25 Oct 2023 15:12:54 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of "SRS0=eRXu=GH=goodmis.org=rostedt@kernel.org" designates 145.40.68.75 as permitted sender) smtp.mailfrom="SRS0=eRXu=GH=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1698246775; h=from:from:sender: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=hSQwP2dY1VP7bG3vjmOs1ra7+KXTGRz3B5SFlCZDPlo=; b=kz/9Jx8Zel26Wc6ZmDQZx1ek0SbAttbwpgc2B1xd4zFHts0YlRP9uvvlnX5muWYaFj+zEf UfDhIH8MnQn4UpcxCCGVC7I12lHgkULeqPO+y7ZxAB4nj4w+j9JK5sh5aH65ys/q5Q5B85 u+jrVX50GM/TzmAXjSbwnxWLAwTRPWQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1698246775; a=rsa-sha256; cv=none; b=ZFCR7gRbpx1lqs3AaVCnad8RsfFJXE6cMDxIIGNlqJ/vyTjF7KBkiaFtt0ttXph9V1jQiw LOt+6uBMCmSCSe1q8FUnTSTwotuhn+rgrmPfvHHyP34BHmob5YAuAVLnbOGIxg6EcRUclH qRj4cp/cFpVjX2HqgffWjDNlSTjh1qY= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of "SRS0=eRXu=GH=goodmis.org=rostedt@kernel.org" designates 145.40.68.75 as permitted sender) smtp.mailfrom="SRS0=eRXu=GH=goodmis.org=rostedt@kernel.org"; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 60134B82FF7; Wed, 25 Oct 2023 15:12:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81FF8C433C7; Wed, 25 Oct 2023 15:12:49 +0000 (UTC) Date: Wed, 25 Oct 2023 11:12:47 -0400 From: Steven Rostedt To: LKML Cc: Thomas Gleixner , Peter Zijlstra , Ankur Arora , Linus Torvalds , linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, Joel Fernandes , Youssef Esmat , Vineeth Pillai , Suleiman Souhlal , Ingo Molnar , Daniel Bristot de Oliveira , Mathieu Desnoyers Subject: Re: [POC][RFC][PATCH] sched: Extended Scheduler Time Slice Message-ID: <20231025111247.64d7b653@gandalf.local.home> In-Reply-To: <20231025054219.1acaa3dd@gandalf.local.home> References: <20231025054219.1acaa3dd@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: triukmnc3m591w36jek8m1rqgzhbocw5 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 31E621C0032 X-Rspam-User: X-HE-Tag: 1698246774-439812 X-HE-Meta: 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 /mVnAJRg rexKlrqXHOBE/28bWn3y6h7zU1iDEW3Br7omyry9Dhzy+fAfTQEPav4H7DFiCL9Eslep6zNsN1ZdFfAl6LnH5+uCtG7ecxQUE6T5RBXWqAP14nybu/gTDS4j0lYP7kKf1t6zr135/n0DQ8v0/ED4B6hKMHMdnE9KkTpDnsgkB+RWrAcQ9fuv4POyGNn5Ia6svo6eGUgdJalSu4Yv0FQ7SlRK7mRaHDpNmaO7FWsP9UNwB2lkKwt6rAXrr98dkqcPGs+di73ojlKmV9dEATFFCz/Cp0+EepFjjkB+iGzqVLMHnaH6x/8aS4Z2fOg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 25 Oct 2023 05:42:19 -0400 Steven Rostedt wrote: > I ran a traceeval tool on it (still work in progress, but I can post when > it's done), and with the following trace, and the writes to trace-marker > (tracefs_printf) > > trace-cmd record -e sched_switch ./extend-sched > > It showed that without the extend, each task was preempted while holding > the lock around 200 times. With the extend, only one task was ever > preempted while holding the lock, and it only happened once! And looking at the trace, it was because it was preempted by an RT task. extend-sched-3349 [007] 3309.320747: print: tracing_mark_write: Have lock! extend-sched-3349 [007] 3309.320751: sched_switch: extend-sched:3349 [120] R ==> migration/7:68 [0] migration/7-68 [007] 3309.320754: sched_switch: migration/7:68 [0] S ==> extend-sched:3349 [120] extend-sched-3349 [007] 3309.320756: print: tracing_mark_write: released lock! So we know that part of the code works. ;-) -- Steve