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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 C6DA0C433EF for ; Fri, 10 Sep 2021 22:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0F096120A for ; Fri, 10 Sep 2021 22:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231782AbhIJWmO (ORCPT ); Fri, 10 Sep 2021 18:42:14 -0400 Received: from mail-lf1-f50.google.com ([209.85.167.50]:44602 "EHLO mail-lf1-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230018AbhIJWmM (ORCPT ); Fri, 10 Sep 2021 18:42:12 -0400 Received: by mail-lf1-f50.google.com with SMTP id s10so7028498lfr.11 for ; Fri, 10 Sep 2021 15:41:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Tybn1JJZvA+Ce9/R67eZt0UWxuTntQ8ckWZHQerPDP4=; b=hqu5anktT3jag6yvQFgES+zhc0M5gUTv45AaZKoO7t/sPl3tO8ZiadhuLN3vs/4NYh io0kwx+n2KP9Rmk1dgE+Kd9deDJymBdxiNc1kD7hM7ixG4Pl/TtM3I4CmCX538O4D3iT iyEpyQ3/jCaf6pvdokxeHQCW42NCGSYrqsywrkiNwGLxzPukeDaboifoNb5Iu8Xsbe3d dlBfTxUHztKUFrsknHD81O89+yyaWpvUe8EiodR0NxapOBR+XptFUuDeb+K4n89odUSy +X86PSrj3gh9Yf05+BRRfmHmnHZN+H1h34X7lNmfHNcNtXJXgqpyxbjRm0YEwBJTRI5V d2Ig== X-Gm-Message-State: AOAM531UixfdF/ytSaZ9MYJ4akMQQPWDKZKJvS9Aev/RNWbvMMZVQUAT D2+PDhi9guNTormAyytNKVhMwoeJ77RbEGu2Hh5ad0iu X-Google-Smtp-Source: ABdhPJw19pmVBGo3jgdwr6zP0n1P7A64zYt/uP5w+hVttkiR3QSSpDlLU4HHlzqVSgY13tAXlUlT9l5ims0SshfppBM= X-Received: by 2002:a05:6512:1528:: with SMTP id bq40mr5562866lfb.71.1631313659550; Fri, 10 Sep 2021 15:40:59 -0700 (PDT) MIME-Version: 1.0 References: <20210908172420.879240-1-namhyung@kernel.org> In-Reply-To: From: Namhyung Kim Date: Fri, 10 Sep 2021 15:40:48 -0700 Message-ID: Subject: Re: [PATCH v2] perf/core: Add a new read format to get a number of lost samples To: Jiri Olsa Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Andi Kleen , Ian Rogers , Michael Petlan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 10, 2021 at 2:42 PM Jiri Olsa wrote: > > On Wed, Sep 08, 2021 at 10:24:20AM -0700, Namhyung Kim wrote: > > Sometimes we want to know an accurate number of samples even if it's > > lost. Currenlty PERF_RECORD_LOST is generated for a ring-buffer which > > might be shared with other events. So it's hard to know per-event > > lost count. > > > > Add event->lost_samples field and PERF_FORMAT_LOST to retrieve it from > > userspace. > > hi, > looks good.. will there be some tools/perf change using this? Sure, I'll work on the userspace part after this is merged. I'm thinking about adding LOST_SAMPLES records at the end of the data section as if they came from the kernel. Thanks, Namhyung