From owner-svn-src-head@FreeBSD.ORG Fri May 29 08:04:16 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 989041065675; Fri, 29 May 2009 08:04:16 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 8A1688FC1E; Fri, 29 May 2009 08:04:14 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by bwz9 with SMTP id 9so6046146bwz.43 for ; Fri, 29 May 2009 01:04:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=3KFt7MOLgRIf6rgpnFyAHBRDs5j8vQDw7tSTB6tc5Gs=; b=WMZL088TrVc3FZ5j6oGwJniYN1skPnD/WfXBtd3EvhBmE2xezHmB7edZSk65P2vCDr aJZkntbrLOEnQ1oU9L7Tgctksn3DW6AwC2r9HFiJ3JjrfJJZzvI4RamSmFG/voTL0Ykc XB8SyVolU6qYvCWa260Vgjh/GglKmV6TmpkMA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=kZDv8P+xcMEkQC6cfVlWQgcZFQ6aZwSZUBOg+PY6DxMZg3xaaib9VE6uoln/p9otn8 Px+Lx0R5sEQYLZTty2mSTSXza3CJJhQGYpVPhMUQTUtIEiqvSorU6x89zDI8N1/ZWGHZ blkh/zw6Fm1BLH3+PBADba8LRHL6oE4ZUbIc4= MIME-Version: 1.0 Sender: asmrookie@gmail.com Received: by 10.223.124.147 with SMTP id u19mr1776421far.28.1243584253774; Fri, 29 May 2009 01:04:13 -0700 (PDT) In-Reply-To: References: <200905290149.n4T1nRJc056207@svn.freebsd.org> Date: Fri, 29 May 2009 10:04:13 +0200 X-Google-Sender-Auth: 2265cca0e108a4be Message-ID: <3bbf2fe10905290104q50d77235pe50a39a3912f6061@mail.gmail.com> From: Attilio Rao To: Robert Watson Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r193011 - in head: . share/man/man9 sys/cddl/compat/opensolaris/sys sys/conf sys/kern sys/sys X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 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, 29 May 2009 08:04:17 -0000 2009/5/29 Robert Watson : > On Fri, 29 May 2009, Attilio Rao wrote: > >> Reverse the logic for ADAPTIVE_SX option and enable it by default. >> Introduce for this operation the reverse NO_ADAPTIVE_SX option. >> The flag SX_ADAPTIVESPIN to be passed to sx_init_flags(9) gets suppressed >> and the new flag, offering the reversed logic, SX_NOADAPTIVE is added. >> >> Additively implements adaptive spininning for sx held in shared mode. >> The spinning limit can be handled through sysctls in order to be tuned >> while the code doesn't reach the release, after which time they should >> be dropped probabilly. > > The princple here has always been that sleepable locks are likely to be used > in sleepable ways, and therefore that adaptive locking (spinning) was > unproductive. In light of these performance results, have you considered > making the same change to lockmgr (assuming it's not there already)? Also, > is adaptive locking for sx locks disabled in Xen by default in the same was > as mutexes? Yes, lockmgrs are the next ones to be handled in regard of this. I'm actually prodding key people abuout experimenting adaptive spinning and reporting to me. Let's see if they can get some interesting benchmark in edge cases (Xen too). Thanks, Attilio -- Peace can only be achieved by understanding - A. Einstein