From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 13 21:28:32 2010 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 E36AA106566B for ; Mon, 13 Sep 2010 21:28:32 +0000 (UTC) (envelope-from cronfy@gmail.com) Received: from mail-bw0-f54.google.com (mail-bw0-f54.google.com [209.85.214.54]) by mx1.freebsd.org (Postfix) with ESMTP id 77FF28FC08 for ; Mon, 13 Sep 2010 21:28:32 +0000 (UTC) Received: by bwz20 with SMTP id 20so323618bwz.13 for ; Mon, 13 Sep 2010 14:28:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:from:date :message-id:subject:to:content-type; bh=OFS21fCPafcBZA8E2xRo2cgr6nGRr74PMqwUVHh7aXE=; b=pLGPdmyuIP2HcmKEzUqd+j8s2kV6rIilRuQ2irVZnHk1gJPO2yVCVnfomQxXV7qebj mI0reWWefZXVM7BuU1C4a/jiGn9kz41qafYPC7x6ysdptPhFRvqGTl/FWq31p9OfEsno Fz5kXMQTQ3z7vovH+g56hIAlmaou0eLXjwBiU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:from:date:message-id:subject:to:content-type; b=OO55HqOXfZW9IWZcYTGVALKo8fWUxb2qFcWME4jm/RGxyuyZq8TJ4x6RHp6Y8SgPSB ktdw7MmV6Dv+eGMZ2oVY8Mp8ZsozgrpXrU9OyDhwKAjOOzH3H0C0FMq6KEY0+g1+sbEC Z6YX85rbqGHudqPlWBLMvF3FmRcNLtCY58On0= Received: by 10.204.85.90 with SMTP id n26mr3623589bkl.109.1284411465116; Mon, 13 Sep 2010 13:57:45 -0700 (PDT) MIME-Version: 1.0 Received: by 10.204.99.197 with HTTP; Mon, 13 Sep 2010 13:57:15 -0700 (PDT) From: cronfy Date: Tue, 14 Sep 2010 00:57:15 +0400 Message-ID: To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: is vfs.lookup_shared unsafe in 7.3? 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, 13 Sep 2010 21:28:33 -0000 Hello, Trying to overtake high server load (sudden peaks of 15%us/85%sy, LA > 40, very slow lstat() at these moments, looks like some kind of lock contention) I enabled vfs.lookup_shared=1 on two servers today. One is FreeBSD-7.3 kernel csup'ed and built Sep 9 2010 and other is FreeBSD-7.3 csup'ed and built Jul 16 2010. The server with more fresh kernel is running nice and does not show high load anymore. But on the second server it did not help. More, after a few hours of work with vfs.lookup_shared=1 I noticed processes stucked in "ufs" state. I tried to kill them with no luck. Disabling vfs.lookup_shared freezed the whole system. So, is vfs.lookup_shared=1 unsafe in 7.3? Did it become more stable between 16 Jul and 9 Sep (is it the reason why first system is still running?), or should I expect that it will freeze in a near time too? Thanks in advance! -- // cronfy