From owner-svn-src-stable-11@freebsd.org Mon Oct 10 18:28:23 2016 Return-Path: Delivered-To: svn-src-stable-11@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 F2AFEC0C95C; Mon, 10 Oct 2016 18:28:23 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98]) (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 B3756AED; Mon, 10 Oct 2016 18:28:23 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD)) (envelope-from ) id 1btfJF-000IPU-P4; Mon, 10 Oct 2016 21:28:21 +0300 Date: Mon, 10 Oct 2016 21:28:21 +0300 From: Slawa Olhovchenkov To: John Baldwin Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: Re: svn commit: r306661 - in stable/11/sys/dev/cxgbe: . tom Message-ID: <20161010182821.GZ54003@zxy.spb.ru> References: <201610032315.u93NFiHE057529@repo.freebsd.org> <20161010110901.GH6177@zxy.spb.ru> <1660024.uzJn2AtV1k@ralph.baldwin.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1660024.uzJn2AtV1k@ralph.baldwin.cx> User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false X-BeenThere: svn-src-stable-11@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for only the 11-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Oct 2016 18:28:24 -0000 On Mon, Oct 10, 2016 at 10:46:27AM -0700, John Baldwin wrote: > On Monday, October 10, 2016 02:09:01 PM Slawa Olhovchenkov wrote: > > On Mon, Oct 03, 2016 at 11:15:44PM +0000, John Baldwin wrote: > > > > > Author: jhb > > > Date: Mon Oct 3 23:15:44 2016 > > > New Revision: 306661 > > > URL: https://svnweb.freebsd.org/changeset/base/306661 > > > > > > Log: > > > MFC 303405: Add support for zero-copy aio_write() on TOE sockets. > > > > > > AIO write requests for a TOE socket on a Chelsio T4+ adapter can now > > > DMA directly from the user-supplied buffer. This is implemented by > > > wiring the pages backing the user-supplied buffer and queueing special > > > mbufs backed by raw VM pages to the socket buffer. The TOE code > > > recognizes these special mbufs and builds a sglist from the VM page > > > array associated with the mbuf when queueing a work request to the TOE. > > > > > > Because these mbufs do not have an associated virtual address, m_data > > > is not valid. Thus, the AIO handler does not invoke sosend() directly > > > for these mbufs but instead inlines portions of sosend_generic() and > > > tcp_usr_send(). > > > > > > An aiotx_buffer structure is used to describe the user buffer (e.g. > > > it holds the array of VM pages and a reference to the AIO job). The > > > special mbufs reference this structure via m_ext. Note that a single > > > job might be split across multiple mbufs (e.g. if it is larger than > > > the socket buffer size). The 'ext_arg2' member of each mbuf gives an > > > offset relative to the backing aiotx_buffer. The AIO job associated > > > with an aiotx_buffer structure is completed when the last reference to > > > the structure is released. > > > > > > Zero-copy aio_write()'s for connections associated with a given > > > adapter can be enabled/disabled at runtime via the > > > 'dev.t[45]nex.N.toe.tx_zcopy' sysctl. > > > > > > Sponsored by: Chelsio Communications > > > > Do you have any public available application patches for support this? > > May be nginx? > > Applications need to use aio_read(), ideally with at least 2 buffers (so > queue two reads, then when a read completes, consume the data and do the > next read). I'm not sure nginx will find this but so useful as web servers > tend to send a lot more data than they receive. The only software I have > patched explicitly for this is netperf. Hm, this is like only aio_read() on sokets give performance boost, not aio_write()?