From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) (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 E6F043B0AE6 for ; Thu, 6 Aug 2026 02:10:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785982245; cv=none; b=YQ5xd9QVFGDQsth3kgvTFaLJZE/5ugadBQRQ6x0vfqIJtrQ1V7HlEnElWGH4OFKmlxsU5Dg8v3J3DJwNJAYnPIy/m3Or/gKdStLFqkwcPGlXbkWrfVFL6s1KyTE9Y5DWGc+OR8ThEpVqnRvxm/0E7dWeei0wRot+XuXn5Uxbpm4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785982245; c=relaxed/simple; bh=Y+TZl/y9/hV+sun39kavC4+lwIlG+BwQf8lj9L/7Mcw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=RI0rFrDBiwe5GRspwJewMCmCsjiF+7kLymbBUEGjNWqjtVt9/kCOBzOYug7frcmgKbJeS8CCJFVBgzKcGV/TEHu9Q4att2jodz2yS8kDhtI5eEVrL6frxshF9O0OCSZkJDz3xNGG7RtiEkGYiMBA6gjUWL7rGCmYCF1OHD0w+3s= 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=Y+zp7rri; arc=none smtp.client-ip=209.85.216.70 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="Y+zp7rri" Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-381250979d5so1828057a91.0 for ; Wed, 05 Aug 2026 19:10:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785982243; x=1786587043; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=PXsoxVGBNSjfiRdARFInMi8AsNaMqbW9uwYEKgGxQWg=; b=Y+zp7rrihJcRwxvAmkj6m1+kHKl4cGjDzEK1AM2FI7x53U9LxrP+Q1ICfnli+ojnwG qWQZQPAOm4ADW4uzSC8iAlYz2M/Lk0XCaKpUcYyP6Tl78SrsfoKWNkNbKBcKdMsy1NdV qQx0Rl7+RPVDg0f7XgJ4Db6uGx0DbA9rAO7uGJRJ2+pohrW9WPqieTfaUw4AkboHdmID dAcbols39xKQ0p8TfHyRspIPJ43JHQRnNps2nSRfq9kEFu8VyGgDiaJuH+tgI0ITK/9U IJqkd/rNkv3ithXfbYYrpzr/ic6KMqXGoo0YIAP8Qt3N+fSOJuhwnFVO9pYXOzyCRas4 eXng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785982243; x=1786587043; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=PXsoxVGBNSjfiRdARFInMi8AsNaMqbW9uwYEKgGxQWg=; b=Zh/Li67CRt7TmOpcOGlekxhzfV5ADZG33F6D5X8Qprrai35x5pzvNd2xGm1dUBpHm7 eY3X5aTk+b2IxyK+dOZSJgpOIXHFGxksEnQS8S6rgYVL/Thd8fd19B/DfFrVmwRsBSeb FAj8AwlyELDtGwz3ukZSba2u3RimJcVAC5gvTWvFMU8zxkqvxyujXJcT8uEHpDeilK4l EWKQpZ5xY4n9eXjyemC6io3aEFDW1TUZ9HdEfW5a0zOD6Isj9mhiY2cpYA/kxK4bREmP 1HcnswTaMTRv7potmoy90P1ZgbQeg+FutzRiilhSLH08p8PCNp+7ssK0TSWBXWluJzjs qHLA== X-Forwarded-Encrypted: i=1; AHgh+RqLtvtvOPsLsM9KsrLKwetWCWoMVfliatvxNXjF6yU7rFHXfCQGEH8cpXe2N4onV3m6f+n7zl2xDEmHnrc=@vger.kernel.org X-Gm-Message-State: AOJu0YwCRMTGXX5u6skGcPQd1uZXPmW8JfG9mAqmxwC92a0M38JsTdGP 74rKHSvYWml6WUXGeRdC01ixwT/gDllG7x71mzOwG9OGwCdaUYjLdkXUZb8hzXGjJ4N/esA7ol/ 8Tb/KwJ7/bQ== X-Received: from dlam17-n1.prod.google.com ([2002:a05:701b:2091:10b0:13b:2d46:494d]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:520a:b0:366:10f1:3d91 with SMTP id 98e67ed59e1d1-3903c54adbamr11271299a91.1.1785982242879; Wed, 05 Aug 2026 19:10:42 -0700 (PDT) Date: Wed, 5 Aug 2026 19:10:38 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.629.g250fe7f194-goog Message-ID: <20260806021038.2291417-1-irogers@google.com> Subject: [PATCH v1] perf evlist: Warn when 'sleep' workload is used without system-wide (-a) option From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tanushree Shah Content-Type: text/plain; charset="UTF-8" A common mistake when trying to record system-wide profiles for a given duration is running commands like 'perf record sleep 1' or 'perf stat sleep 1' without passing '-a' / '--all-cpus'. When '-a' is omitted, perf defaults to per-process monitoring of the sleep process itself, which does not collect system-wide activity and records very few events. Add a warning in evlist__prepare_workload() when the workload executable is 'sleep' and system-wide mode is not enabled. Signed-off-by: Ian Rogers --- tools/perf/util/evlist.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index eb7c0d7be064..d53f594ace86 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1562,6 +1562,20 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const int child_ready_pipe[2], go_pipe[2]; char bf; + if (argv && argv[0] && target && !target->system_wide) { + const char *cmd = strrchr(argv[0], '/'); + + if (cmd) + cmd++; + else + cmd = argv[0]; + + if (!strcmp(cmd, "sleep")) { + ui__warning("workload '%s' specified without the system-wide (-a) option\n", + cmd); + } + } + evlist__set_workload_cork_fd(evlist, -1); if (pipe(child_ready_pipe) < 0) { -- 2.55.0.629.g250fe7f194-goog