From owner-svn-src-head@freebsd.org Fri May 27 20:34:40 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5D9D6B4D273; Fri, 27 May 2016 20:34:40 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: from mail-io0-f176.google.com (mail-io0-f176.google.com [209.85.223.176]) (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 2CCF31892; Fri, 27 May 2016 20:34:39 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: by mail-io0-f176.google.com with SMTP id 190so78980799iow.1; Fri, 27 May 2016 13:34:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:reply-to:in-reply-to:references :date:message-id:subject:from:to:cc:content-transfer-encoding; bh=/fzDeDTlctSGxxLrL6NiACKqTT39WSV1eu5YkpDuhv0=; b=Rep536JFdXv+ZXwH58y2LbmCUDbT4lXli0cm8Qba8srS6AcP8CEpJ15HRCFPDKqEzy CrX1P4Z+9vGtAcx4G36vtDR60y/suvjrM+bMCPQhVOoq1X3H0PJrGlxqg2SuklQTz3aD l4SPcc5ZIVf97Nz1cY+AwYNXA6ootAM6SUURs0iVhzTHzjoVgsLLlv3I+VJ3AlseQnLM Y0kv/h/LjqgOTWpXs96UbSti0WgZkj4h6MsFysheUX8Kvw2t7suZUSqkpq40/GiPmEXI T715/TzzoPqLXl9GdgAi6tlyKg/03x00/qPuZ2InN3VElsri+E+4yhmJbm1ubonTfJL5 Y3Nw== X-Gm-Message-State: ALyK8tKNFMYxiZm89QSrrboJG2zSP4BIXnBybR1eSrDo59VP5Ec0oTDirZZaJsarwkciuA== X-Received: by 10.107.41.84 with SMTP id p81mr16732203iop.106.1464381273072; Fri, 27 May 2016 13:34:33 -0700 (PDT) Received: from mail-it0-f48.google.com (mail-it0-f48.google.com. [209.85.214.48]) by smtp.gmail.com with ESMTPSA id e66sm6579600iof.18.2016.05.27.13.34.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 May 2016 13:34:32 -0700 (PDT) Received: by mail-it0-f48.google.com with SMTP id z189so3036910itg.0; Fri, 27 May 2016 13:34:32 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.36.158.69 with SMTP id p66mr396366itd.97.1464381272387; Fri, 27 May 2016 13:34:32 -0700 (PDT) Reply-To: cem@FreeBSD.org Received: by 10.36.205.70 with HTTP; Fri, 27 May 2016 13:34:32 -0700 (PDT) In-Reply-To: <201605272012.u4RKCWCI035708@repo.freebsd.org> References: <201605272012.u4RKCWCI035708@repo.freebsd.org> Date: Fri, 27 May 2016 13:34:32 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r300868 - head/tools/tools/ioat From: Conrad Meyer To: Garrett Cooper Cc: src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 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, 27 May 2016 20:34:40 -0000 On Fri, May 27, 2016 at 1:12 PM, Garrett Cooper wrote: > Author: ngie > Date: Fri May 27 20:12:32 2016 > New Revision: 300868 > URL: https://svnweb.freebsd.org/changeset/base/300868 > > Log: > Remove note about bogus chain-len maximum > > There's no current limit on chain-len with Broadwell DE chips; it isn't > enforced in software, and there doesn't appear to be a hardware limitat= ion > either on the Intel Xeon D-1527 (Broadwell-DE) chip. Hi Ngie, The note isn't bogus, it's just not what you think it is=E2=80=94the limit = is in the ioat_test code, not a limit of the hardware. Before this commit which documented it (r289733), the limit *was* 4. However, in the same commit I bumped the limit up to 128 (IOAT_MAX_BUFS / 2). (I suspect I wrote the documentation first, before deciding to raise the limit.) So the current limit is 128, and should be documented. Thanks, Conrad