From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32B8D1ADC67; Fri, 23 May 2025 22:21:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748038918; cv=none; b=XMu6Tafm2LJ+FVhAO4Rc7Ou3Ja1OoKG0P7QpworjEy3uf3AphCGz9HsJtbwj9fXC8E8Sy13ctOqSau/lkV9dG5ZhzPG0VdvTd5AW78fcnNtNRfdwE0X7fQ/PdwVX6l5jwbrbAkSmWyWacN7++hoqEFTiakWqB4ejJUCrf4CePc8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748038918; c=relaxed/simple; bh=AiDAoyQjHRv2JDTsgsxGZeHVPr7H6J1azUzkcdYGflg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=UOoGLLC2nv2c9mTVx2hoiBra7pRdMs9txYadZSexI2FUI7tFoa1gAKrHWfWGY/+MdGJZESjMSUKlclH8GlcE0Sp7M93E18niPX2M+JcUup9t9hv171XExYDzLA9mzRyUx3Sd2gPJbHA8SpB5/F1tzcSTm2n+YWe1eX3vmniVyrk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z4xh3qfX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z4xh3qfX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E805C4CEEF; Fri, 23 May 2025 22:21:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748038918; bh=AiDAoyQjHRv2JDTsgsxGZeHVPr7H6J1azUzkcdYGflg=; h=From:To:Cc:Subject:Date:From; b=Z4xh3qfXOt31hAXeYQCqZzobkM2LLD4tPVMEuzNnrMHPNuhLP1igFwOSu2Z/tMm3h LIpcmF+ZtJNhmODyPHm3QoyeARMFTiA/SSdYJEMQuhXobRWBIdPhZSodYMNdoali+V WGXjLdBlWn9+qlgUM1f+kMQ/XyHvFFBXl+yNk7iJ4CEKylqxp1aooWXl0gMkT7Im3C zOtvf6P+dAbkZYMwzNDmjn3AhK57IuuDBPaeuXcpWyIYsUgNJnTNW6wpqfrvMagsro Zain0DzBXjcyDSux6hNb4U8cobtwGSUT8vjFHHdRpaSkhf7K3qDSuJAZJGtCOcyMz1 7Rf/tFFZFFcZg== From: Namhyung Kim To: Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Ravi Bangoria , Leo Yan , Stephane Eranian Subject: [PATCH 1/3] perf mem: Describe overhead calculation in brief Date: Fri, 23 May 2025 15:21:55 -0700 Message-ID: <20250523222157.1259998-1-namhyung@kernel.org> X-Mailer: git-send-email 2.49.0.1151.ga128411c76-goog Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ravi Bangoria Unlike perf-report which uses sample period for overhead calculation, perf-mem overhead is calculated using sample weight. Describe perf-mem overhead calculation method in it's man page. Signed-off-by: Ravi Bangoria Signed-off-by: Namhyung Kim --- tools/perf/Documentation/perf-mem.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt index a9e3c71a220557d4..965e73d377724607 100644 --- a/tools/perf/Documentation/perf-mem.txt +++ b/tools/perf/Documentation/perf-mem.txt @@ -137,6 +137,25 @@ REPORT OPTIONS In addition, for report all perf report options are valid, and for record all perf record options. +OVERHEAD CALCULATION +-------------------- +Unlike linkperf:perf-report[1], which calculates overhead from the actual +sample period, perf-mem overhead is calculated using sample weight. E.g. +there are two samples in perf.data file, both with the same sample period, +but one sample with weight 180 and the other with weight 20: + + $ perf script -F period,data_src,weight,ip,sym + 100000 629080842 |OP LOAD|LVL L3 hit|... 20 7e69b93ca524 strcmp + 100000 1a29081042 |OP LOAD|LVL RAM hit|... 180 ffffffff82429168 memcpy + + $ perf report -F overhead,symbol + 50% [.] strcmp + 50% [k] memcpy + + $ perf mem report -F overhead,symbol + 90% [k] memcpy + 10% [.] strcmp + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-report[1], linkperf:perf-arm-spe[1] -- 2.49.0.1151.ga128411c76-goog