From owner-svn-src-head@freebsd.org Fri May 4 22:38:34 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9D61FFBA2EA; Fri, 4 May 2018 22:38:34 +0000 (UTC) (envelope-from mjguzik@gmail.com) Received: from mail-qt0-x242.google.com (mail-qt0-x242.google.com [IPv6:2607:f8b0:400d:c0d::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 40D7D7E715; Fri, 4 May 2018 22:38:34 +0000 (UTC) (envelope-from mjguzik@gmail.com) Received: by mail-qt0-x242.google.com with SMTP id g13-v6so29419349qth.8; Fri, 04 May 2018 15:38:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=74Wqc4BxTRTcIMk4wiVtzL2kHTLMjmZj2zX4bzgdBGU=; b=o+UZNtiU66OGPbBFqql+d79r0aI3xGBuaStQsPqxdjEKPwbO5PWQNawAj+3/c8sYIj lgoBiJRAd6x5oKNvmnrfamv0XPPdm0NPpMSskgGcE3K4hXYsie8NG1rLM+zJjsrAxDlV /nG+OtkOG1HYTjRRpIpxz9kphB4zJMeDzeRRWawygfkJHyI1WOpeCC2D9UR1pClbWtJp JBKFBQT1U9uX69oLJ07THUB/ZmoI8zQleWhfCkSMzpynLkemEvXZS7k/2T4jo4UPTn+w TAXvRfiLfDtbe3ycPr9xWcJX5FJaHx67VIliUdVGtqVN/cHdnzaPHQe0NeTige0B4L15 f2Cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=74Wqc4BxTRTcIMk4wiVtzL2kHTLMjmZj2zX4bzgdBGU=; b=FXKHfLwmxQyfQkOEtbSkTPWDfFLZsD0Yn69d2bJjB5yEq/AascByHNN9Wt/FSPx5Xh ZwGkPwIPaZ9GsiTi6VYT68ucSDentrJOfgjHnRsSg3NPdMMClGxO0GNudflZkM5ftZW9 RGuI3h9PqJO31bxk7dhFKELzPH99r8scc1Noo40DcalYHoqlGPlKCQvqRl3W9wh4DLH/ n1aM4VgCJ4OADl7k4GLEAC7ToGuX3ewoznLqVjuoYFRD5jycnwicRf9Lx1EA9ptiMAF1 6UCVl6g5b+ud/HAx1bsvVQ5Z4yQ746RDjqFKkmUlbSLxdoGV7OmzlyRmpvo9qWdwGPxk zukQ== X-Gm-Message-State: ALQs6tAgIuzop1/b87tQ5HrZy7UAGXFZYDjmuIBOPyopJy6bYIp5Jz6v JMt4hdTeuD3S2lJIkny8KcZFS+cpuoLBoLKWDbw= X-Google-Smtp-Source: AB8JxZpaN4kJwOMtmSGms1zMknMIwzxAQABBmZooDAAs0TUwBqjQBXCkyd9HU7jXvpJeSSG/UX/7Sg2zCu+MbX1THuI= X-Received: by 2002:a0c:b2c2:: with SMTP id d2-v6mr9507555qvf.16.1525473513672; Fri, 04 May 2018 15:38:33 -0700 (PDT) MIME-Version: 1.0 Received: by 10.200.28.74 with HTTP; Fri, 4 May 2018 15:38:33 -0700 (PDT) In-Reply-To: <20180504155301.GA56280@spindle.one-eyed-alien.net> References: <201805040400.w4440moH025057@repo.freebsd.org> <20180504155301.GA56280@spindle.one-eyed-alien.net> From: Mateusz Guzik Date: Sat, 5 May 2018 00:38:33 +0200 Message-ID: Subject: Re: svn commit: r333240 - in head/sys: powerpc/powerpc sys To: Brooks Davis Cc: Mateusz Guzik , src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 04 May 2018 22:38:34 -0000 On Fri, May 4, 2018 at 5:53 PM, Brooks Davis wrote: > On Fri, May 04, 2018 at 04:00:48AM +0000, Mateusz Guzik wrote: > > Author: mjg > > Date: Fri May 4 04:00:48 2018 > > New Revision: 333240 > > URL: https://svnweb.freebsd.org/changeset/base/333240 > > > > Log: > > Allow __builtin_memmove instead of bcopy for small buffers of known > size > > What is the justification for forcing a size rather than using the > compiler's built-in fallback to memmove? Is the kernel compilation > environment disabling that? > > It will fallback to memmove which is super pessimized as being wrapped around bcopy. These limits will get lifted after the fallback routines get sorted out. -- Mateusz Guzik