From nobody Fri Feb 11 12:31:49 2022 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 1A09A19ABBDB; Fri, 11 Feb 2022 12:31:56 +0000 (UTC) (envelope-from mpp302@gmail.com) Received: from mail-ej1-f49.google.com (mail-ej1-f49.google.com [209.85.218.49]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JwCfh05sdz4qp2; Fri, 11 Feb 2022 12:31:56 +0000 (UTC) (envelope-from mpp302@gmail.com) Received: by mail-ej1-f49.google.com with SMTP id p24so22637804ejo.1; Fri, 11 Feb 2022 04:31:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=ST+rlAZwhGj2OQwfOy2vA3DZ1L8iYBTWu418zCO1R/M=; b=cO9AZL+8Ex/78IAvSjM1c+dmKB1irElzWOCs2uVqcRi7Df4dxVoST/4+8MvJL/f/KD O58U/M2RHLvKAGgH04QCXKqgqygZNBwk/PmR5GqC+nAFTnLtnxExW4jPf+9vkK95CuDK mgxDKlYJhr5xX47zPLNZC2YmMvzWzZbqFB5JSa0p4xJtUzqHpB0iu5jZmU1TF4f1HNAQ YLIvTX2xulWrOa2tjhTCCa9HVn2wdTsz8K7LDA1VOPaeN+kdcEHcJeVTqolTZ1hqg3hw 3jsnI6vYiFk4DyzyrglfrlT9JnGvpWUwOSqTQdDPoA4POGuecmKz6y0ItUGqKxpg0jYQ RQ2Q== X-Gm-Message-State: AOAM532C3Fbdx4fyDWVf7tCz+GCV4w2W9eaoOQRqpmgwjYb/LneMgEdc 5LHz5yXETHQEldH14dUJqOL2ZsL2lylFZucb X-Google-Smtp-Source: ABdhPJyasw1CD3XGz8U1t95LATFRF3XytArdoEYaFVWz7pokPv3uKgByD9W6iB1v9kjDh6lqZEuErw== X-Received: by 2002:a17:906:af63:: with SMTP id os3mr1233214ejb.204.1644582708578; Fri, 11 Feb 2022 04:31:48 -0800 (PST) Received: from [192.168.0.104] (ip5f5bd4cf.dynamic.kabel-deutschland.de. [95.91.212.207]) by smtp.gmail.com with ESMTPSA id i9sm9402327eda.35.2022.02.11.04.31.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 11 Feb 2022 04:31:47 -0800 (PST) Message-ID: <38e73169-d322-4c8f-0781-ac60e67c66da@FreeBSD.org> Date: Fri, 11 Feb 2022 13:31:49 +0100 List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: git: f339a3ef6369 - main - dtrace: remove unnecessary fflush() Content-Language: en-US To: Chuck Silvers Cc: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org, dtrace@freebsd.org References: <202202100248.21A2mMWw070398@gitrepo.freebsd.org> <50175512-5528-f93f-33cf-90f92f2e41b1@FreeBSD.org> From: Mateusz Piotrowski <0mp@FreeBSD.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4JwCfh05sdz4qp2 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-ThisMailContainsUnwantedMimeParts: N On 10/02/2022 20:32, Chuck Silvers wrote: > On Thu, Feb 10, 2022 at 02:36:30PM +0100, Mateusz Piotrowski wrote: >> >> Did you have some specific way to measure the CPU overhead of DTrace here? >> I'm interested in this kind of performance measurements and I wonder if >> anything more sophisticated than observing top(1) was used to test this >> change. Thanks! > I just looked at top and saw that the CPU usage of the dtrace process > dropped from 100% to around 13%. More importantly, when the fflush was > present dtrace would report that millions of output records were being > dropped, and after the fflush was removed then dtrace no longer reported > any dropped output. Thanks! Mateusz