From owner-cvs-src@FreeBSD.ORG Mon Jan 22 15:01:06 2007 Return-Path: X-Original-To: cvs-src@freebsd.org Delivered-To: cvs-src@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D3D0916A40E for ; Mon, 22 Jan 2007 15:01:06 +0000 (UTC) (envelope-from andre@freebsd.org) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.freebsd.org (Postfix) with ESMTP id 49C7213C457 for ; Mon, 22 Jan 2007 15:01:06 +0000 (UTC) (envelope-from andre@freebsd.org) Received: (qmail 80887 invoked from network); 22 Jan 2007 14:40:54 -0000 Received: from c00l3r.networx.ch (HELO [127.0.0.1]) ([62.48.2.2]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 22 Jan 2007 14:40:54 -0000 Message-ID: <45B4D1AF.9070101@freebsd.org> Date: Mon, 22 Jan 2007 16:01:03 +0100 From: Andre Oppermann User-Agent: Thunderbird 1.5.0.9 (Windows/20061207) MIME-Version: 1.0 To: John Baldwin References: <200611021745.kA2HjSZC018731@repoman.freebsd.org> <200701121206.47308.jhb@freebsd.org> In-Reply-To: <200701121206.47308.jhb@freebsd.org> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/kern uipc_socket.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jan 2007 15:01:06 -0000 John Baldwin wrote: > On Thursday 02 November 2006 12:45, Andre Oppermann wrote: >> andre 2006-11-02 17:45:28 UTC >> >> FreeBSD src repository >> >> Modified files: >> sys/kern uipc_socket.c >> Log: >> Use the improved m_uiotombuf() function instead of home grown sosend_copyin() >> to do the userland to kernel copying in sosend_generic() and sosend_dgram(). >> >> sosend_copyin() is retained for ZERO_COPY_SOCKETS which are not yet supported >> by m_uiotombuf(). >> >> Benchmaring shows significant improvements (95% confidence): >> 66% less cpu (or 2.9 times better) with new sosend vs. old sosend (non-TSO) >> 65% less cpu (or 2.8 times better) with new sosend vs. old sosend (TSO) >> >> (Sender AMD Opteron 852 (2.6GHz) with em(4) PCI-X-133 interface and receiver >> DELL Poweredge SC1425 P-IV Xeon 3.2GHz with em(4) LOM connected back to back >> at 1000Base-TX full duplex.) >> >> Sponsored by: TCP/IP Optimization Fundraise 2005 >> MFC after: 3 month > > This breaks writes of 0 bytes (e.g. write(s, NULL, 0)) to sockets because > m_getm2(NULL, 0, ...) returns NULL and thus m_uiotombuf() returns NULL and > sosend_*() now return EFAULT. sosend_copyin() correctly handles this case > since it always allocates at least one mbuf. I'm not sure if m_uiotombuf() > is at fault or if something else is, so I'll let you fix it. This explains > the recent breakage of kcheckpass (KDE screen saver password checker) on > current, and possibly other things as well. Fix is committed. Thank you for tracking it down. > Also, you've introduced another regression in that if the m_get2m() fails it > should be returning ENOBUFS and not EFAULT to userland. The comments in > sosend_*() about 'EFAULT being the only possible error' are obviously > wrong. :) We're always calling with M_WAITOK because we're coming from userland and may sleep forever. -- Andre