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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C21B8C433E0 for ; Fri, 3 Jul 2020 00:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD40920748 for ; Fri, 3 Jul 2020 00:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726297AbgGCAnQ (ORCPT ); Thu, 2 Jul 2020 20:43:16 -0400 Received: from mga01.intel.com ([192.55.52.88]:44080 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgGCAnQ (ORCPT ); Thu, 2 Jul 2020 20:43:16 -0400 IronPort-SDR: nbIl1QTTtlJIsUzwnP8Gu+eJKM43RF7TdGqA3/NJBPf6GexnUL5Kp13c9V1l8pN8e5nYKNizBu gTl4vbD7Aesw== X-IronPort-AV: E=McAfee;i="6000,8403,9670"; a="165119489" X-IronPort-AV: E=Sophos;i="5.75,306,1589266800"; d="scan'208";a="165119489" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jul 2020 17:43:15 -0700 IronPort-SDR: +3BATNlpnb2LhdaxdKRXQ83hMGdtC/P2mVh6XB5Up5u23Hh6dO5qDqdPK/s72/zJvMJyE5gAJA qXkHLfcIJ1vQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,306,1589266800"; d="scan'208";a="356619200" Received: from kbl-ppc.sh.intel.com ([10.239.159.118]) by orsmga001.jf.intel.com with ESMTP; 02 Jul 2020 17:43:13 -0700 From: Jin Yao To: acme@kernel.org, jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com Cc: Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com, irogers@google.com, Jin Yao Subject: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event Date: Fri, 3 Jul 2020 08:42:15 +0800 Message-Id: <20200703004215.24418-1-yao.jin@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"), a dummy event is added to capture mmaps. But if we run perf-record as, # perf record -e cycles:p -IXMM0 -a -- sleep 1 Error: dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' The issue is, if we enable the extended regs (-IXMM0), but the pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel will return -EOPNOTSUPP error. See following code pieces. /* in kernel/events/core.c */ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) { .... if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) && has_extended_regs(event)) ret = -EOPNOTSUPP; .... } For software dummy event, the PMU should be not set with PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy event has possibility to be set with PERF_REG_EXTENDED_MASK bit. In evsel__config, /* tools/perf/util/evsel.c */ if (opts->sample_intr_regs) { attr->sample_regs_intr = opts->sample_intr_regs; } If we use -IXMM0, the attr>sample_regs_intr will be set with PERF_REG_EXTENDED_MASK bit. It doesn't make sense to set attr->sample_regs_intr for a software dummy event. This patch adds dummy event checking before setting attr->sample_regs_intr. After: # ./perf record -e cycles:p -IXMM0 -a -- sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ] Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis") Signed-off-by: Jin Yao --- tools/perf/util/evsel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 96e5171dce41..df3315543e86 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts, if (callchain && callchain->enabled && !evsel->no_aux_samples) evsel__config_callchain(evsel, opts, callchain); - if (opts->sample_intr_regs) { + if (opts->sample_intr_regs && !is_dummy_event(evsel)) { attr->sample_regs_intr = opts->sample_intr_regs; evsel__set_sample_bit(evsel, REGS_INTR); } - if (opts->sample_user_regs) { + if (opts->sample_user_regs && !is_dummy_event(evsel)) { attr->sample_regs_user |= opts->sample_user_regs; evsel__set_sample_bit(evsel, REGS_USER); } -- 2.17.1