From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f47.google.com (mail-pj1-f47.google.com [209.85.216.47]) (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 8893F38B for ; Sat, 20 Jul 2024 00:31:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721435468; cv=none; b=LL4hcasODN51Fv44mIv4Aoadp9MNxxOgOw3fQOq1O+Ie7p5/NaF3cW0WLZTpcK1y4GGqL2duHWMv//G+lwrUgUxvT/DlTTyYXlHvXcwuzZtjQgbyBpTCWvh44mKKkgvZ6f64QyinOo2BgO3KuYKZa++HmgSSGeXLNupMRhkJgOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721435468; c=relaxed/simple; bh=QRDZb5ikRj0UdWgYCZCzNNA/EFtRVJbdJWn12CXARU8=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=PrtLhipguY0d3rFD2Fm7gH9ZchXxpcJRjnGDGYYxrils73uFlQM0DKVEXTA5Vna+umpL6KAPRyWNx0UaE/LJPefkwhiygVmD2igL2P+BFTcW9OLVDt5dzwUUGD42ge6cypuPw1MkC4aeFyTvNND0jy/H6fb0q0Sw/5WaE/9WVBM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.216.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pj1-f47.google.com with SMTP id 98e67ed59e1d1-2cb64529a36so1343491a91.0 for ; Fri, 19 Jul 2024 17:31:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721435467; x=1722040267; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cAIHzmq3NEgiChDl7GC1hvoHM3qtCt5CRxnsglGybuw=; b=rYO63N1HVnHkB1U+ljxHT8aFhWeaBp9JvCAg2O9l3iq5Jvj92KtgVHyAyW/BPwJnBM LReB7uTqD8NOB4ILccjnTGi2fkqP563O1B9Tjd6KObbjGVyxi2F7YNNTw2w/7x4SznhC bgC/J0DXhUmIOjsUmyZYW6/VXt78FbN4B0MhVYpvNitop+UzG+Sdnu9HxkUi5B6y1UWT 1leBwKpjBMhoCDbi3hR4Yvre+4qqbOcTfeRx/vukaQckhb4+QfliJ24SfJqt+3qk1+Jz oLi3x1Zw8t3jjaeNKprvaTPmTT77z8aUGe6TYs3IuyGyqaAy4EmHBkf1pZOhhSIcWit/ 44JA== X-Forwarded-Encrypted: i=1; AJvYcCVfRl9yM6L5dL1SJQxxtS5CU/Gzn83PoLSS4yQxzilTJyTSdeOrsTLzZ4m5E7KZcFbdkcJ01Jd5XwcsO4931cPch1k7xJheEcfmoZQjFTo84w== X-Gm-Message-State: AOJu0YydfNrt2RvQdp9B0myB9/4H+7znG00d556yBpzxc0EjmwqQrgiO FoTlAR2UvNWwtvNchN2825ncM0XN5ehPmJ8mspJzSJImSoqKeEQ04v/YPmYK5QMnJ1CnZ51Nzht j6uNibBJAFCLA9KYfFQ/i6x3PkN4= X-Google-Smtp-Source: AGHT+IEVw3aV19wuuXgbGV8sx7G0AWDA89h31mpzX4adopBjqxBtopa02nQ7DvX57hoo0neKbf5zzIt6Pqb7T5GaOfM= X-Received: by 2002:a17:90a:f195:b0:2c9:9f50:3f9d with SMTP id 98e67ed59e1d1-2cd273f7547mr59765a91.5.1721435466629; Fri, 19 Jul 2024 17:31:06 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Namhyung Kim Date: Fri, 19 Jul 2024 17:30:55 -0700 Message-ID: Subject: Re: perf test fail :: "perf stat --bpf-counters --for-each-cgroup test" To: Michael Petlan Cc: acme@redhat.com, vmolnaro@redhat.com, linux-perf-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello, On Fri, Jul 19, 2024 at 2:50=E2=80=AFAM Michael Petlan = wrote: > > Hello Namhyung, > > we were investigating some test failures of the testcase mentioned > in $subj. We have narrowed it down to: > > # perf stat -C 0,1 --for-each-cgroup system.slice,user.slice -e cycle= s -- taskset -c 1 perf test -w thloop > > Performance counter stats for 'CPU(s) 0,1': > cycles system.slice > 3,020,401,084 cycles user.slice > > 1.009787097 seconds time elapsed > > As seen, the system.slice is not counted properly in our case. It > happens even without bpf-counters being involved. > > There were rumours that it might be caused due to too small system > load, but it apparently happens even when the load was replaced by > "thloop" workload from perf-test's workload library. However, even > so, if the load was insufficient, we'd see a value =E2=80=93 0 instead of > "not counted". The "" result is printed if the counter > wasn't properly enabled and running. > > Have you encountered this problem? What could cause it? Sometimes, it depends on the system activity. I assumed there would be some system operation running on the given CPUs at any time. If not, it can fail.. Thanks, Namhyung