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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 3F4F9C83000 for ; Wed, 29 Apr 2020 16:22:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1550F206F0 for ; Wed, 29 Apr 2020 16:22:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="BXBo9OXz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726776AbgD2QWv (ORCPT ); Wed, 29 Apr 2020 12:22:51 -0400 Received: from forwardcorp1o.mail.yandex.net ([95.108.205.193]:42548 "EHLO forwardcorp1o.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726456AbgD2QWv (ORCPT ); Wed, 29 Apr 2020 12:22:51 -0400 Received: from mxbackcorp1j.mail.yandex.net (mxbackcorp1j.mail.yandex.net [IPv6:2a02:6b8:0:1619::162]) by forwardcorp1o.mail.yandex.net (Yandex) with ESMTP id DEF262E097C; Wed, 29 Apr 2020 19:22:47 +0300 (MSK) Received: from vla1-81430ab5870b.qloud-c.yandex.net (vla1-81430ab5870b.qloud-c.yandex.net [2a02:6b8:c0d:35a1:0:640:8143:ab5]) by mxbackcorp1j.mail.yandex.net (mxbackcorp/Yandex) with ESMTP id zCzNk2WdeO-MiWOmUe2; Wed, 29 Apr 2020 19:22:47 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1588177367; bh=qvivbKulTADbj1G5HSZtFfM6sU/7nUqZpncf5ziB99E=; h=In-Reply-To:Message-ID:References:Date:To:From:Subject:Cc; b=BXBo9OXzDIiZqamVd66xfOV6xGvJj8RKiAYaoIFWhYWmHRZF4nGoy/682Huvr/L7N skZ2wZUmacXhmqqBoM57HDp81xtZhsyI2v79ToQy5QjEVpPE9m2L4oQeNaJCxWKq9u JTYfmcF8aUIPPKGqmu4r8kMggfCHgSsOZQiyB9/8= Authentication-Results: mxbackcorp1j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-vpn.dhcp.yndx.net (dynamic-vpn.dhcp.yndx.net [2a02:6b8:b080:7913::1:4]) by vla1-81430ab5870b.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id jXZZ6t05sz-MhX0JEgG; Wed, 29 Apr 2020 19:22:43 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) Subject: [PATCH v2 2/3] perf tool: fix detecting smt at machines with more than 32 cpus From: Konstantin Khlebnikov To: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar Cc: Kan Liang , Jiri Olsa , Andi Kleen , Dmitry Monakhov Date: Wed, 29 Apr 2020 19:22:43 +0300 Message-ID: <158817735893.747933.15107805593224835078.stgit@buzz> In-Reply-To: <158817718710.747528.11009278875028211991.stgit@buzz> References: <158817718710.747528.11009278875028211991.stgit@buzz> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cpu bitmap is split into 32 bit words. For system with more than 32 cores threads are always in different words thus first word never has two bits: cpu0: "0000,00000100,00000001", cpu 79: "8000,00000080,00000000". Instead of parsing bitmap read "core_cpus_list" or "thread_siblings_list" and simply check presence of ',' or '-' in it. Signed-off-by: Konstantin Khlebnikov Fixes: de5077c4e38f ("perf tools: Add utility function to detect SMT status") --- tools/perf/util/smt.c | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-) diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c index 8481842e9edb..dc37b5abd1c3 100644 --- a/tools/perf/util/smt.c +++ b/tools/perf/util/smt.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include "api/fs/fs.h" #include "smt.h" @@ -9,39 +10,35 @@ int smt_on(void) { static bool cached; static int cached_result; + int active; int cpu; int ncpu; + char *str = NULL; + size_t strlen; if (cached) return cached_result; ncpu = sysconf(_SC_NPROCESSORS_CONF); for (cpu = 0; cpu < ncpu; cpu++) { - unsigned long long siblings; - char *str; - size_t strlen; char fn[256]; - snprintf(fn, sizeof fn, - "devices/system/cpu/cpu%d/topology/core_cpus", cpu); - if (sysfs__read_str(fn, &str, &strlen) < 0) { - snprintf(fn, sizeof fn, - "devices/system/cpu/cpu%d/topology/thread_siblings", - cpu); - if (sysfs__read_str(fn, &str, &strlen) < 0) - continue; - } - /* Entry is hex, but does not have 0x, so need custom parser */ - siblings = strtoull(str, NULL, 16); - free(str); - if (hweight64(siblings) > 1) { - cached_result = 1; - cached = true; + snprintf(fn, sizeof(fn), "devices/system/cpu/cpu%d/topology/%s", + cpu, "core_cpus_list"); + if (sysfs__read_str(fn, &str, &strlen) > 0) + break; + + snprintf(fn, sizeof(fn), "devices/system/cpu/cpu%d/topology/%s", + cpu, "thread_siblings_list"); + if (sysfs__read_str(fn, &str, &strlen) > 0) break; - } } + + active = str && (strchr(str, ',') != NULL || strchr(str, '-') != NULL); + free(str); + if (!cached) { - cached_result = 0; + cached_result = active; cached = true; } return cached_result;