From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id A492244B7F for ; Fri, 7 Apr 2023 16:16:20 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 65DFD68B187; Fri, 7 Apr 2023 19:16:16 +0300 (EEST) Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id BAA13689C14 for ; Fri, 7 Apr 2023 19:16:10 +0300 (EEST) Received: by mail-qt1-f175.google.com with SMTP id h3so14268752qtu.1 for ; Fri, 07 Apr 2023 09:16:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=obe-tv.20210112.gappssmtp.com; s=20210112; t=1680884169; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=IHnmqHu/F07WJHIqZf+EEBvtjqpPEbXOXN1nT+y8gOk=; b=mvjA9C2El6RuMLIUMpsCxezQ2FDfh2K147DvoJWmQXxLRNngoKnQFKlyGCXKwh6aNt bGl5GI5LnMWbPis3gMQPXa3S0Op0W8210TJT6aGbOQfo1mDa2slbBl1EjfIwmZNWwRHT BZVPU7Jap1vK9XF8joqcBp06DNM7qfeo0tQt49LH/0bD/p57pxzJrWCSR5jGqSmkCgKG 4vADFAEMK/85DQuWi8hwDuaht/YBvXWnd2GlllVUWtwoQBUTxeACshquyBqt8JGnqrDq 95dPcaD9fzVqbqeYl8Z4l1giOC0ztnkxbusPoTFp4HcN+m0UkMTYQCWpav4d0YK8PEmE 094g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680884169; h=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=IHnmqHu/F07WJHIqZf+EEBvtjqpPEbXOXN1nT+y8gOk=; b=nuXVhfz0V1iC5orWLDz17cKM6y8YhkMrDoUceMC7ASk8fHi126/UjiH/zJBU4Gw/97 Q+97tciMZyHdVZjkm4xGhakOpLeVUtKlBAZ6MZRNNLZKloYq9elPdAM/sNO0+mLYvpNM SeCCipKo9bHkGMLRyYadbPPhLLAR56m+2il/STLxLg3enPlfy2WMimXecX4lSey34QSO o57wO3rbfRYL4pjaXobkYqotXWuiNncTmJ2z5fRnQV5UpA3y6Jt0QiszqUoXrUSloufV ZmNU9/R6meg7Q9yvB1G7Bp3Hww8+ZzWVGkRJPX+x07VnST/vlqLExsGqRfaE3Hcq8INY Bw/A== X-Gm-Message-State: AAQBX9cnzfxHa9BaOCulTVcEgrYgZpSodl6eQYYDMb87af6NCjRcsgO7 TLtTz4WzsTXoy+VYtfGR2ckCiZbX+PZhJk6+p9H/fAP0SqK7dCSq X-Google-Smtp-Source: AKy350Z2qr5ZfbiNWsgPO/cu3VwJXsajlCfaIVJRZw1TwV3ZDPlzkWpTiE8n9Ht/9nHVBh7PtFsvrJex0Ijypzw75Ds= X-Received: by 2002:a05:622a:1115:b0:3de:1720:b54b with SMTP id e21-20020a05622a111500b003de1720b54bmr916709qty.0.1680884166914; Fri, 07 Apr 2023 09:16:06 -0700 (PDT) MIME-Version: 1.0 References: <94f54c4a-d530-f197-e3fe-5e7df5ef54af@davyandbeth.com> In-Reply-To: From: Kieran Kunhya Date: Fri, 7 Apr 2023 17:15:56 +0100 Message-ID: To: FFmpeg development discussions and patches X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: Re: [FFmpeg-devel] ffmpeg appears to be wasting CPU time X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Fri, 7 Apr 2023 at 05:03, Davy Durham wrote: > After furiously digging through the ffmpeg code (particularly in older > versions that also exhibit the problem, but where the code is simpler) I > have found no reason for there to be wasted CPU time. > > In my travels, I frustratingly noticed that sometime the problem would > mysteriously vanish. And, long story short, I believe I've been chasing > a phantom. If, on my local machine w/ 8 cores, I start a process that > simply spins one CPU, the problem vanishes--that is, now whether running > ffmpeg at full speed or with a read rate limit, the cumulative CPU > reported by 'time' is nearly** the same, as one would expect it to be. > Are you sure this isn't just your CPU governor and/or the effects of frequency scaling/C-states? Kieran _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".