From owner-freebsd-hackers@FreeBSD.ORG Fri May 12 11:28:25 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4D5FC16A401 for ; Fri, 12 May 2006 11:28:25 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail26.syd.optusnet.com.au (mail26.syd.optusnet.com.au [211.29.133.167]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4754643D6E for ; Fri, 12 May 2006 11:28:23 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail26.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k4CBSArA017345 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Fri, 12 May 2006 21:28:16 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.6/8.13.6) with ESMTP id k4CBSAnd001784; Fri, 12 May 2006 21:28:10 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.6/8.13.6/Submit) id k4CBSAfT001783; Fri, 12 May 2006 21:28:10 +1000 (EST) (envelope-from peter) Date: Fri, 12 May 2006 21:28:09 +1000 From: Peter Jeremy To: Iasen Kostov Message-ID: <20060512112809.GD714@turion.vk2pj.dyndns.org> Mail-Followup-To: Peter Jeremy , Iasen Kostov , FreeBSD Hackers References: <1147264089.51661.10.camel@DraGoN.OTEL.net> <1147264379.51661.14.camel@DraGoN.OTEL.net> <1147265038.51661.19.camel@DraGoN.OTEL.net> <1147361590.33341.19.camel@DraGoN.OTEL.net> <20060512071711.GA714@turion.vk2pj.dyndns.org> <1147428461.98918.10.camel@DraGoN.OTEL.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1147428461.98918.10.camel@DraGoN.OTEL.net> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.11 Cc: FreeBSD Hackers Subject: Re: Heavy system load by pagedaemon 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: Fri, 12 May 2006 11:28:25 -0000 On Fri, 2006-May-12 13:07:41 +0300, Iasen Kostov wrote: >On Fri, 2006-05-12 at 17:17 +1000, Peter Jeremy wrote: >> 'page daemon wakeups' counts the number of times that the pagedaemon >> is woken up due to a page shortage. I think I was not correct here. It looks like the pagedaemon can be woken up (via vm_pages_needed) even if vm_pages_needed is still zero. >> How about posting a complete 'vmstat -s'. I spoke too soon. The relevant counters are in vm.stats.vm.* and not reported by vmstat. >But there is something else: >"collecting pv entries -- suggest increasing PMAP_SHPGPERPROC" x 5 times >(which is it maximum number of this warrnings). The call tree for this is vm_pageout() with wakeup(&vm_pages_needed) && vm_pages_needed == 0 vm_pageout_scan() vm_pageout_pmap_collect() with pmap_pagedaemon_waken non-zero. vm_pageout_pmap_collect() runs with Giant held and, based on a very brief check, looks quite expensive. >When I checked sysctl vm.zone I saw "PV ENTRY" going near to it's >maximum right before the lock happen and then after the lock by >pagedaemon it go down to ~1000 You mentioned eaccelerator and having lots of users and httpd. I suspect the comment in NOTES is relevant for you and you need to increase PMAP_SHPGPERPROC as recommended: # Set the number of PV entries per process. Increasing this can # stop panics related to heavy use of shared memory. However, that can # (combined with large amounts of physical memory) cause panics at # boot time due the kernel running out of VM space. # # If you're tweaking this, you might also want to increase the sysctls # "vm.v_free_min", "vm.v_free_reserved", and "vm.v_free_target". # # The value below is the one more than the default. # options PMAP_SHPGPERPROC=201 -- Peter Jeremy