From owner-freebsd-hackers@FreeBSD.ORG Mon Mar 30 05:03:33 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 52BBC1065672; Mon, 30 Mar 2009 05:03:33 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id E1F298FC17; Mon, 30 Mar 2009 05:03:32 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from phobos.local ([192.168.254.200]) (authenticated bits=0) by pooker.samsco.org (8.14.2/8.14.2) with ESMTP id n2U53GDt073333; Sun, 29 Mar 2009 23:03:16 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <49D05294.6040200@samsco.org> Date: Sun, 29 Mar 2009 23:03:16 -0600 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.13) Gecko/20080313 SeaMonkey/1.1.9 MIME-Version: 1.0 To: David Xu References: <11609492.9579.1238167614335.JavaMail.root@vms070.mailsrvcs.net> <49CD0405.1060704@samsco.org> <49CD30E9.7030501@elischer.org> <49CEC261.4010803@freebsd.org> <49CF0523.8020905@elischer.org> <49D022EF.8030305@freebsd.org> <49D023B7.8070402@freebsd.org> <49D04F63.4010800@elischer.org> <49D0518D.4040000@freebsd.org> In-Reply-To: <49D0518D.4040000@freebsd.org> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-4.4 required=3.8 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on pooker.samsco.org X-Mailman-Approved-At: Mon, 30 Mar 2009 11:14:30 +0000 Cc: Sergey Babkin , freebsd-hackers@freebsd.org, attilio@freebsd.org, phk@phk.freebsd.dk, freebsd-current@freebsd.org, Julian Elischer , prashant.vaibhav@gmail.com Subject: Re: Improving the kernel/i386 timecounter performance (GSoC proposal) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Mar 2009 05:03:34 -0000 David Xu wrote: > Julian Elischer wrote: >> David Xu wrote: >>> David Xu wrote: >>>> Julian Elischer wrote: >>>> >>>>> depends on the hardware. >>>>> anyhow I was only saying it was possible, not necessarily >>>>> good or even useful. >>>>> >>>>> >>>> >>>> I had done some works for thread private page shared by kernel >>>> and userland when I was doing userland spinlock, if userland asks >>>> a page, kernel will allocate it and put some interesting thing in >>>> it by scheduler etcs, these code may be useful. >>>> >>> FYI: >>> http://people.freebsd.org/~davidxu/schedctl/ >> >> reading this quickly, you allocate a separately addressed page for >> each thread, but, how do you use it? >> >> > I store the address in userland TLS area, then get it when I want to > check some scheduling informations. > Interesting, I was wondering earlier today if pointing to the per-thread syspage in from the TLS area would save the TLB invalidate that you were concerned about. Scott