From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D39632DEA7A for ; Wed, 3 Dec 2025 21:47:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764798444; cv=none; b=UxRaNFNtIZlCrf7res3GMuG3e5628pCAQ5DmHcxcpQ+gwQlKjPGJoNtY7kReybVlY0luhUo4OhgfisTrw1EUy3ZfvOHt6Kel9jpVy70pfg9D1yMLX+kgk32TIlPlK/GCowlYvERg8kCrvau+PnM0t6lqC9s3mSUbxjWYk3+XCbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764798444; c=relaxed/simple; bh=rCDV+3XVuXJlJQb0sFK0j2R1k8EuktUog2utuwzxKNc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=MFimAAZGI2Cv5dtQXOZwz9dDI5NjWq4j4v0JJEVd6DWsrcz17X6AgjWC+YKeH+AN8r53oXDS213CaX7KFfuAvIfFvvSjDOIKgrVhp1J3St7i8XvCmaNiCI72kCB35laGxx0f6Q8Or9lUSn5g8YWX4a2yM39yW9o2rLEXjrRx/04= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=1XhuY+qW; arc=none smtp.client-ip=209.85.215.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="1XhuY+qW" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-bc0de474d4eso418467a12.0 for ; Wed, 03 Dec 2025 13:47:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1764798442; x=1765403242; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=Eo+kFEEYhTtGZ8S2xC5G3JMQxS58EmO+MrIvA5H8Swc=; b=1XhuY+qWKDDD94ypPW+YzSuUHQ8XXHcfN1ftpoOCb6otTEy6aHPbaH155S3576Aryl 7B4m6iQaSi3jQFTe3SE7ogaZSQErVgccFNOYJKnfZGA2AjLa9fBEfOxxiIqny9KLjcAM AIiLsJ0phFZ+Mij+sV5UMkEATlakm9slT+JtTqPCWAe3QsRQM7CzOJbdgDMnw2OVGMKz E7JhVyRhuhv2ETOHeGCkT/HLKWbZCjWi5X+EQ3ajCHk4mEXoqH6z/zHgo4ARPMOG6dFP 9zkf1nZbXFyc+TM/QSFM4Yw0hTEfso6VfC3gee2PFJxGegeY9zq07Ta0GOoXJNEbzDsp ToOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764798442; x=1765403242; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Eo+kFEEYhTtGZ8S2xC5G3JMQxS58EmO+MrIvA5H8Swc=; b=gd5JC0Egtnm4SSUMbDZgr1zr2yvfn+TlO/UCpggJe8MAcGhwsNBFgy5dVRduS+XwLZ m4Em3tgpeab7T+cjMtKMyfeleFwEkEeUrDpSWwuErdTD1qQrn+arZyBE8eEOOxWEq4xT DZKDpqicXjd7DvKxuwxZ8b0Dw9qA0E/wRuI4DkRmrVnlWG0tsV5T1YesuBJjox6XFUEn ggMdnQRYitUJ5c5ib82IlSCO8OIAIcNbQSXymKa7B4bM4A2wY8MYMOgN9A+g9KaRMHss inM8F1rtkbg4IHvsKi92v/6LZBUjd7fVIUrtRBwXTr+j36KYeam9kgZ4zDGhHTw9lEeq tSlA== X-Forwarded-Encrypted: i=1; AJvYcCUBu2fqNVW8zs1hvNE29RM2KIgP31GBM7tiSr02TxEd85rpXI77S4ajPumOkaWlsrDuDoTTtq7Yg/+rqww4LcUR@vger.kernel.org X-Gm-Message-State: AOJu0YyRKJkOTNl/3yrv2ysqqqymwqIfcy+RDQ+rWzLAFOyNlS+bSI38 7kssSzvUWNfYQ0VIIK8DGU9Mv9JqCFFkFaJ6rrF0ROClXFIa0Zxwnoyvwpv2tb/lRy+kU4EYzrp YNeRfU+269Q== X-Google-Smtp-Source: AGHT+IHhe6kRQZx177bgCgxvMbSS9SftVF+Bm/qVvJrVFF8Tsu5NAx3LcXp7XVpP0fOBqaUyYQBGvjc1lKmz X-Received: from dybgh9.prod.google.com ([2002:a05:7301:9:b0:2a4:559f:7c4e]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7300:d024:b0:2ab:9e2d:a466 with SMTP id 5a478bee46e88-2aba4235517mr639323eec.12.1764798442027; Wed, 03 Dec 2025 13:47:22 -0800 (PST) Date: Wed, 3 Dec 2025 13:47:04 -0800 In-Reply-To: <20251203214706.112174-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251203214706.112174-1-irogers@google.com> X-Mailer: git-send-email 2.52.0.177.g9f829587af-goog Message-ID: <20251203214706.112174-6-irogers@google.com> Subject: [PATCH v2 5/7] perf stat: When no events, don't report an error if there is none From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Thomas Richter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Events may fail to open as no supported CPUs were specified on the command line. In this case a confusing "error" message of "success" can be reported. Let's skip the error in that case. Before: ``` $ perf stat -C2048 -e cycles -- true WARNING: A requested CPU in '2048' is not supported by PMU 'cpu' (CPUs 0-7) for event 'cycles' Error: No supported events found. The sys_perf_event_open() syscall returned with 0 (Success) for event (cpu/unknown-hardware/). "dmesg | grep -i perf" may provide additional information. ``` After: ``` $ perf stat -C2048 -e cycles -- true WARNING: A requested CPU in '2048' is not supported by PMU 'cpu' (CPUs 0-7) for event 'cycles' Error: No supported events found. ``` Signed-off-by: Ian Rogers --- tools/perf/builtin-stat.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 6410115ed9c5..bd3c3de8d200 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -924,8 +924,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) } } if (!has_supported_counters && !stat_config.null_run) { - evsel__open_strerror(evlist__first(evsel_list), &target, open_err, - msg, sizeof(msg)); + if (open_err) { + evsel__open_strerror(evlist__first(evsel_list), &target, open_err, + msg, sizeof(msg)); + } ui__error("No supported events found.\n%s\n", msg); if (child_pid != -1) -- 2.52.0.177.g9f829587af-goog