From owner-svn-src-head@freebsd.org Fri May 27 20:58:33 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 52E14B4D8B3; Fri, 27 May 2016 20:58:33 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: from mail-oi0-f43.google.com (mail-oi0-f43.google.com [209.85.218.43]) (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 2290A1D0A; Fri, 27 May 2016 20:58:32 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: by mail-oi0-f43.google.com with SMTP id w184so185186903oiw.2; Fri, 27 May 2016 13:58:32 -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=uslhMFR6WLgjwqWj6MlpyxMxmKsUV0YCcGcrcgfpEKU=; b=aP4+KMsXlSdKgREjrfURYPlVNWo67Ot+ndpoYIfkpNt8SN/rW9MdKK06W+9XOetjSl lrge/vap4B2UFkX78WQ0rohD3p+UtP/AppdSyc1a9DnETkQRFIkxpc9zGrZoaFXJCO+J ZrqLjckrzA8aaGS0MeZleEqTXiOKH0XUB2Nmu/rXlZQCAfrOfB9h92otqj6qQFCsAHyz hIC4RE8shehR9FKROYvju5wxzt1AJ6G477B4wtK2t5WHSprMc+Ix4h5OPlI2G2fTuS5E G08SEcMSRydfMBom80oAXGFrZRE4UzyX1Bv8KtPZUyS0tgvYCT3/ldlDPkUe3QyJ9g3F UEPA== X-Gm-Message-State: ALyK8tICDJN9GPWiDBZr3khaYz6n3qru+882Cz18NjiLQyuaJYq43SiYVIrdfMTS6ROeMA== X-Received: by 10.202.82.195 with SMTP id g186mr11437276oib.70.1464382711838; Fri, 27 May 2016 13:58:31 -0700 (PDT) Received: from mail-io0-f177.google.com (mail-io0-f177.google.com. [209.85.223.177]) by smtp.gmail.com with ESMTPSA id m7sm9887842otm.41.2016.05.27.13.58.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 May 2016 13:58:31 -0700 (PDT) Received: by mail-io0-f177.google.com with SMTP id p64so38294724ioi.2; Fri, 27 May 2016 13:58:31 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.107.38.79 with SMTP id m76mr17363949iom.7.1464382711121; Fri, 27 May 2016 13:58:31 -0700 (PDT) Reply-To: cem@FreeBSD.org Received: by 10.36.205.70 with HTTP; Fri, 27 May 2016 13:58:31 -0700 (PDT) In-Reply-To: <2F93033E-D202-4A0A-8555-76ED789D4080@gmail.com> References: <201605272012.u4RKCWCI035708@repo.freebsd.org> <2F93033E-D202-4A0A-8555-76ED789D4080@gmail.com> Date: Fri, 27 May 2016 13:58:31 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r300868 - head/tools/tools/ioat From: Conrad Meyer To: "Ngie Cooper (yaneurabeya)" Cc: Garrett Cooper , 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 20:58:33 -0000 I don't think such infrastructure is needed for simple test code like this. 128 is more than enough. On Fri, May 27, 2016 at 1:51 PM, Ngie Cooper (yaneurabeya) wrote: > >> On May 27, 2016, at 13:34, Conrad Meyer wrote: >> >> 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 limita= tion >>> 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 lim= it 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. > > Ah=E2=80=A6 that makes sense. Would it be a better idea to make this limi= t into a readonly sysctl in ioat_test(4), along with the other limits? If s= o, I=E2=80=99ll put that out for CR. > Thanks, > -Ngie