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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 6EE4DC47254 for ; Fri, 8 May 2020 13:09:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B836249A4 for ; Fri, 8 May 2020 13:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730415AbgEHNJm (ORCPT ); Fri, 8 May 2020 09:09:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1730489AbgEHNFV (ORCPT ); Fri, 8 May 2020 09:05:21 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B9A6C05BD0B; Fri, 8 May 2020 06:05:21 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jX2gi-0007Zc-P4; Fri, 08 May 2020 15:05:12 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 7B3DB1C0493; Fri, 8 May 2020 15:05:00 +0200 (CEST) Date: Fri, 08 May 2020 13:05:00 -0000 From: "tip-bot2 for Konstantin Khlebnikov" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf tools: Simplify checking if SMT is active. Cc: Konstantin Khlebnikov , Andi Kleen , Dmitry Monakhov , Jiri Olsa , Kan Liang , Peter Zijlstra , Arnaldo Carvalho de Melo , x86 , LKML In-Reply-To: <158817741394.748034.9273604089138009552.stgit@buzz> References: <158817741394.748034.9273604089138009552.stgit@buzz> MIME-Version: 1.0 Message-ID: <158894310042.8414.3876806843338881034.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: bb629484d924118e3b1d8652177040115adcba01 Gitweb: https://git.kernel.org/tip/bb629484d924118e3b1d8652177040115adcba01 Author: Konstantin Khlebnikov AuthorDate: Wed, 29 Apr 2020 19:23:41 +03:00 Committer: Arnaldo Carvalho de Melo CommitterDate: Tue, 05 May 2020 16:35:29 -03:00 perf tools: Simplify checking if SMT is active. SMT now could be disabled via "/sys/devices/system/cpu/smt/control". Status is shown in "/sys/devices/system/cpu/smt/active" simply as "0" / "1". If this knob isn't here then fallback to checking topology as before. Signed-off-by: Konstantin Khlebnikov Cc: Andi Kleen Cc: Dmitry Monakhov Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/158817741394.748034.9273604089138009552.stgit@buzz Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/smt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c index 8481842..20bacd5 100644 --- a/tools/perf/util/smt.c +++ b/tools/perf/util/smt.c @@ -15,6 +15,9 @@ int smt_on(void) if (cached) return cached_result; + if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) > 0) + goto done; + ncpu = sysconf(_SC_NPROCESSORS_CONF); for (cpu = 0; cpu < ncpu; cpu++) { unsigned long long siblings; @@ -42,6 +45,7 @@ int smt_on(void) } if (!cached) { cached_result = 0; +done: cached = true; } return cached_result;