From owner-svn-src-all@FreeBSD.ORG Mon Nov 3 08:28:58 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id C392AE9; Mon, 3 Nov 2014 08:28:58 +0000 (UTC) Received: from mail.turbocat.net (heidi.turbocat.net [88.198.202.214]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 81A70C1C; Mon, 3 Nov 2014 08:28:58 +0000 (UTC) Received: from laptop015.home.selasky.org (cm-176.74.213.204.customer.telag.net [176.74.213.204]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 307331FE022; Mon, 3 Nov 2014 09:28:54 +0100 (CET) Message-ID: <54573CD2.1000702@selasky.org> Date: Mon, 03 Nov 2014 09:29:06 +0100 From: Hans Petter Selasky User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Julian Elischer , Mateusz Guzik , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r274017 - head/sys/kern References: <201411030746.sA37kpPu037113@svn.freebsd.org> <54573AEE.9010602@freebsd.org> <54573B87.7000801@freebsd.org> In-Reply-To: <54573B87.7000801@freebsd.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Nov 2014 08:28:58 -0000 On 11/03/14 09:23, Julian Elischer wrote: > On 11/3/14, 4:21 PM, Julian Elischer wrote: >> On 11/3/14, 3:46 PM, Mateusz Guzik wrote: >>> Author: mjg >>> Date: Mon Nov 3 07:46:51 2014 >>> New Revision: 274017 >>> URL: https://svnweb.freebsd.org/changeset/base/274017 >>> >>> Log: >>> Provide an on-stack temporary buffer for small ioctl requests. >> I'm not sure I like this. We don't know how many more levels >> of stack may be needed. >> I know that machines are getting faster with more memory, >> but the current move towards bloating out the > ... "bloating out the stack" ... >> worries me. we started out with a single page of stack (SHARED >> with the U-area!). I think we are now at several pages.. I forget, is >> it 8? >> I'm open to being persuaded but I think we need to have a discussion >> about stack usage. We used to say that anything greater that, say >> 64 bytes should probably be allocated. >> Hi, I think this patch can give a benefit for the USB stack and CUSE4BSD, because it does frequent IOCTLs. Regarding the stack usage, maybe this general purpose optimisation can be allocated from the thread structure? --HPS