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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FC88C433F5 for ; Fri, 15 Oct 2021 06:29:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F9006115C for ; Fri, 15 Oct 2021 06:29:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234499AbhJOGbV (ORCPT ); Fri, 15 Oct 2021 02:31:21 -0400 Received: from mail-lf1-f51.google.com ([209.85.167.51]:34405 "EHLO mail-lf1-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232562AbhJOGbT (ORCPT ); Fri, 15 Oct 2021 02:31:19 -0400 Received: by mail-lf1-f51.google.com with SMTP id t9so36600152lfd.1 for ; Thu, 14 Oct 2021 23:29:13 -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=GSexlnSfHHqSZ1JMsDFapEU6NoUx9lAdrel84RuUOqM=; b=MKAMkTXE52FBwUZsS0OzWJ9SzQ3Y2Pkw+lLMiSke6EV1YZqxe+pkTtmHzRrZX6eJJj eClY+pMb7ZTud0fBtTuBxTdNMy7Jjsv1isWZvOsaBDzE/MsqecbaikSw9nYeukXZ9Xr9 uZ2DYDXKMPkCJ3yXrhMmLoYnE0S2RcGkGN1RzLQm0Rnl+ZYTM4/SvqrJF6dveI6iNk7e pbYDJyjgw78hR9Zhyl+nRWiRl2NFPcHKZiRyEpfrkF7WTUcqNwSwaHDgY+BlcDFB79K5 0JzfTLtesFg17HDKaKj/ldOsTJukVoCmcCDx1/J0/OJ3fwFdMTEOyAb+eq8Uvtp98vJd Sd3A== X-Gm-Message-State: AOAM533Nnu+MJfnig73NLlvTENv9unioVSr0zuC/UQQNo3yDYfz4tLHe 7ACNB/Ui0e6w/vtRpFn4TVP3z+lKKeVB8lESojYuXVbi X-Google-Smtp-Source: ABdhPJz72cBsZnGYGPvk1ocWFo/8K1qJ8rhfdKfjtJy3BRrp2epXhkOksBd5opSWxA2tlaaM7mHiIm/uNJiuJBbD4To= X-Received: by 2002:a05:6512:68b:: with SMTP id t11mr1889368lfe.586.1634279352587; Thu, 14 Oct 2021 23:29:12 -0700 (PDT) MIME-Version: 1.0 References: <20210908172420.879240-1-namhyung@kernel.org> In-Reply-To: From: Namhyung Kim Date: Thu, 14 Oct 2021 23:29:01 -0700 Message-ID: Subject: Re: [PATCH v2] perf/core: Add a new read format to get a number of lost samples To: Peter Zijlstra Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Andi Kleen , Ian Rogers , Michael Petlan , Jiri Olsa Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping! On Wed, Sep 22, 2021 at 12:34 PM Namhyung Kim wrote: > > Hi Peter, > > On Fri, Sep 10, 2021 at 3:40 PM Namhyung Kim wrote: > > > > 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. > > Can I get your feedback? > > Thanks, > Namhyung