From owner-freebsd-current@FreeBSD.ORG Fri Aug 24 16:56:08 2012 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DAD8C1065670; Fri, 24 Aug 2012 16:56:08 +0000 (UTC) (envelope-from alc@rice.edu) Received: from mh10.mail.rice.edu (mh10.mail.rice.edu [128.42.201.30]) by mx1.freebsd.org (Postfix) with ESMTP id A72008FC14; Fri, 24 Aug 2012 16:56:08 +0000 (UTC) Received: from mh10.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh10.mail.rice.edu (Postfix) with ESMTP id 2695060502; Fri, 24 Aug 2012 11:56:08 -0500 (CDT) Received: from mh10.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh10.mail.rice.edu (Postfix) with ESMTP id 25150604EB; Fri, 24 Aug 2012 11:56:08 -0500 (CDT) X-Virus-Scanned: by amavis-2.7.0 at mh10.mail.rice.edu, auth channel Received: from mh10.mail.rice.edu ([127.0.0.1]) by mh10.mail.rice.edu (mh10.mail.rice.edu [127.0.0.1]) (amavis, port 10026) with ESMTP id LSSo-lDGt7QB; Fri, 24 Aug 2012 11:56:08 -0500 (CDT) Received: from adsl-216-63-78-18.dsl.hstntx.swbell.net (adsl-216-63-78-18.dsl.hstntx.swbell.net [216.63.78.18]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) (Authenticated sender: alc) by mh10.mail.rice.edu (Postfix) with ESMTPSA id B48EC604FC; Fri, 24 Aug 2012 11:56:07 -0500 (CDT) Message-ID: <5037B226.3000103@rice.edu> Date: Fri, 24 Aug 2012 11:56:06 -0500 From: Alan Cox User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:8.0) Gecko/20111113 Thunderbird/8.0 MIME-Version: 1.0 To: Luigi Rizzo References: <20120822120105.GA63763@onelab2.iet.unipi.it> <20120823163145.GA3999@onelab2.iet.unipi.it> <50366398.2070700@rice.edu> <20120823174504.GB4820@onelab2.iet.unipi.it> <50371485.1020409@rice.edu> <20120824145708.GA16557@onelab2.iet.unipi.it> <5037A803.6030100@rice.edu> <20120824165428.GA17495@onelab2.iet.unipi.it> In-Reply-To: <20120824165428.GA17495@onelab2.iet.unipi.it> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: alc@freebsd.org, current@freebsd.org Subject: Re: less aggressive contigmalloc ? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Aug 2012 16:56:08 -0000 On 08/24/2012 11:54, Luigi Rizzo wrote: > On Fri, Aug 24, 2012 at 11:12:51AM -0500, Alan Cox wrote: >> On 08/24/2012 09:57, Luigi Rizzo wrote: >>> On Fri, Aug 24, 2012 at 12:43:33AM -0500, Alan Cox wrote: >>>> On 08/23/2012 12:45, Luigi Rizzo wrote: >>>>> On Thu, Aug 23, 2012 at 12:08:40PM -0500, Alan Cox wrote: >>>>> ... >>>>>>> yes i do see that. >>>>>>> >>>>>>> Maybe less aggressive with M_NOWAIT but still kills processes. >>>>>> Are you compiling world with MALLOC_PRODUCTION? The latest version of >>>>> whatever the default is. But: >>>>> >>>>>> jemalloc uses significantly more memory when debugging options are >>>>>> enabled. This first came up in a thread titled "10-CURRENT and swap >>>>>> usage" back in June. >>>>>> >>>>>> Even at its most aggressive, M_WAITOK, contigmalloc() does not directly >>>>>> kill processes. If process death coincides with the use of >>>>>> contigmalloc(), then it is simply the result of earlier, successful >>>>>> contigmalloc() calls, or for that matter any other physical memory >>>>>> allocation calls, having depleted the pool of free pages to the point >>>>>> that the page daemon runs and invokes vm_pageout_oom(). >>>>> does it mean that those previous allocations relied on memory >>>>> overbooking ? >>>> Yes. >>>> >>>>> Is there a way to avoid that, then ? >>>> I believe that malloc()'s default minimum allocation size is 4MB. You >>>> could reduce that. >>>> >>>> Alternatively, you can enable MALLOC_PRODUCTION. >>> i tried this, and as others mentioned it makes life >>> better and reduces the problem but contigmalloc still triggers >>> random process kills. >> I would be curious to see a stack backtrace when vm_pageout_oom() is called. > you mean a backtrace of the process(es) that get killed ? No, a backtrace showing who called vm_pageout_oom(). Simply add a kdb_backtrace() call at the start of vm_pageout_oom(). There are two possibilities. I want to know which it is.