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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B4F0BC433ED for ; Mon, 26 Apr 2021 05:40:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8ACC461263 for ; Mon, 26 Apr 2021 05:40:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231829AbhDZFkg (ORCPT ); Mon, 26 Apr 2021 01:40:36 -0400 Received: from mga01.intel.com ([192.55.52.88]:29258 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbhDZFkf (ORCPT ); Mon, 26 Apr 2021 01:40:35 -0400 IronPort-SDR: 139w858mWYGkfMWXtpNSMBs0NLpsvalKNpW0S32yUv24U5ZRGHe16A2F0+0JtK560xgKnvweu5 fXh/yvft9ypg== X-IronPort-AV: E=McAfee;i="6200,9189,9965"; a="216979245" X-IronPort-AV: E=Sophos;i="5.82,251,1613462400"; d="scan'208";a="216979245" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Apr 2021 22:39:51 -0700 IronPort-SDR: biyUaBdAexN6+2TN5TJCfWhh2CjsjNSjzmviRAjwOv/w2fDrX2Lec5llX1X3FPcE+aAZteZp64 YRaTuzBM6QTA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,251,1613462400"; d="scan'208";a="422503436" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.174]) ([10.237.72.174]) by fmsmga008.fm.intel.com with ESMTP; 25 Apr 2021 22:39:48 -0700 Subject: Re: [PATCH v1 2/3] perf session: Add swap operation for event TIME_CONV To: Leo Yan , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , "Gustavo A. R. Silva" , Steve MacLean , Yonatan Goldschmidt , Kan Liang , linux-kernel@vger.kernel.org References: <20210412083459.462817-1-leo.yan@linaro.org> <20210412083459.462817-3-leo.yan@linaro.org> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <1b4fa7c3-79cd-6f73-873e-4792b8a1b732@intel.com> Date: Mon, 26 Apr 2021 08:40:00 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210412083459.462817-3-leo.yan@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/04/21 11:34 am, Leo Yan wrote: > Since commit d110162cafc8 ("perf tsc: Support cap_user_time_short for > event TIME_CONV"), the event PERF_RECORD_TIME_CONV has extended the data > structure for clock parameters. > > To be backwards-compatible, this patch adds a dedicated swap operation > for the event PERF_RECORD_TIME_CONV, based on checking the event size, > it can support both for the old and new event formats. > > Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV") > Signed-off-by: Leo Yan > --- > tools/perf/util/session.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 9a8808507bd9..afca3d5fc851 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -949,6 +949,26 @@ static void perf_event__stat_round_swap(union perf_event *event, > event->stat_round.time = bswap_64(event->stat_round.time); > } > > +static void perf_event__time_conv_swap(union perf_event *event, > + bool sample_id_all __maybe_unused) > +{ > + size_t time_zero_size; > + > + event->time_conv.time_shift = bswap_64(event->time_conv.time_shift); > + event->time_conv.time_mult = bswap_64(event->time_conv.time_mult); > + event->time_conv.time_zero = bswap_64(event->time_conv.time_zero); > + > + time_zero_size = (void *)&event->time_conv.time_cycles - (void *)event; > + if (event->header.size > time_zero_size) { I wonder if we could have a helper for this e.g. (untested) #define event_contains(obj, mem) (obj.header.size > offsetof(typeof(obj), mem)) if (event_contains(event->time_conv, time_cycles)) { > + event->time_conv.time_cycles = bswap_64(event->time_conv.time_cycles); > + event->time_conv.time_mask = bswap_64(event->time_conv.time_mask); > + event->time_conv.cap_user_time_zero = > + bswap_32(event->time_conv.cap_user_time_zero); > + event->time_conv.cap_user_time_short = > + bswap_32(event->time_conv.cap_user_time_short); 'struct perf_record_time_conv' contains bool, the sizeof which, AFAIK, is not defined. Is it really 4 bytes on your implementation? It is only 1 byte with gcc on x86. Either way, you should change 'struct perf_record_time_conv' so it uses a type of known size. Since you are the only one using it, it should match your implementation. > + } > +} > + > typedef void (*perf_event__swap_op)(union perf_event *event, > bool sample_id_all); > > @@ -985,7 +1005,7 @@ static perf_event__swap_op perf_event__swap_ops[] = { > [PERF_RECORD_STAT] = perf_event__stat_swap, > [PERF_RECORD_STAT_ROUND] = perf_event__stat_round_swap, > [PERF_RECORD_EVENT_UPDATE] = perf_event__event_update_swap, > - [PERF_RECORD_TIME_CONV] = perf_event__all64_swap, > + [PERF_RECORD_TIME_CONV] = perf_event__time_conv_swap, > [PERF_RECORD_HEADER_MAX] = NULL, > }; > >