From owner-freebsd-current@FreeBSD.ORG Mon Sep 24 13:04:38 2007 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 053A116A419; Mon, 24 Sep 2007 13:04:38 +0000 (UTC) (envelope-from ler@lerctr.org) Received: from thebighonker.lerctr.org (thebighonker.lerctr.org [192.147.25.65]) by mx1.freebsd.org (Postfix) with ESMTP id C429B13C45B; Mon, 24 Sep 2007 13:04:37 +0000 (UTC) (envelope-from ler@lerctr.org) Received: from thebighonker.lerctr.org ([192.147.25.65]:64353) by thebighonker.lerctr.org with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.68 (FreeBSD)) (envelope-from ) id 1IZnc3-000Luz-KV; Mon, 24 Sep 2007 08:04:37 -0500 Date: Mon, 24 Sep 2007 08:04:33 -0500 (CDT) From: Larry Rosenman To: Kris Kennaway In-Reply-To: <46F78C59.1020801@FreeBSD.org> Message-ID: <20070924080347.O84223@thebighonker.lerctr.org> References: <20070921102946.T11189@borg> <46F415BF.9010500@FreeBSD.org> <20070921140550.D96923@thebighonker.lerctr.org> <46F41CFF.6080108@FreeBSD.org> <46F58799.1030702@freebsd.org> <46F58B21.8030307@FreeBSD.org> <20070924091558.GB32006@team.vega.ru> <46F78C59.1020801@FreeBSD.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Score: -4.4 (----) X-LERCTR-Spam-Score: -4.4 (----) X-Spam-Report: SpamScore (-4.4/5.0) ALL_TRUSTED=-1.8,BAYES_00=-2.599 X-LERCTR-Spam-Report: SpamScore (-4.4/5.0) ALL_TRUSTED=-1.8,BAYES_00=-2.599 DomainKey-Status: no signature Cc: Darren Reed , freebsd-current@FreeBSD.org, Ruslan Ermilov Subject: Re: panic: kmem_malloc(131072): kmem_map too small (AMD64) 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: Mon, 24 Sep 2007 13:04:38 -0000 On Mon, 24 Sep 2007, Kris Kennaway wrote: > Ruslan Ermilov wrote: >> On Sat, Sep 22, 2007 at 11:37:37PM +0200, Kris Kennaway wrote: >>> Darren Reed wrote: >>>> Kris Kennaway wrote: >>>>> Larry Rosenman wrote: >>>>>> On Fri, 21 Sep 2007, Kris Kennaway wrote: >>>>>> >>>>>>> Larry Rosenman wrote: >>>>>>>> I'm a heavy ZFS user, and got the following panic on 2007-09-18 >>>>>>>> source/world: >>>>>>> This is a FAQ, please see the archives (you need to increase the >>>>>>> vm.kmem_size to provide more memory to ZFS). >>>>>> I thought that was only for i386, and it hadn't been an issue before. >>>>> Nope. It is also load-dependent. >>>> So I just received this courtesy of ZFS: >>>> panic: kmem_malloc(131072): kmem_map too small: 343027712 total allocated >>>> cpuid = 0 >>>> KDB: enter: panic >>>> This was with these settings in loader.conf: >>>> vm.kmem_size=419430400 >>>> vm.kmem_size_max=419430400 >> >> Setting both doesn't make sense; kmem_size will take over. >> kmem_size_max only limits the automatically computed value >> of kmem_size, which is: >> >> /* >> * How many physical pages per KVA page allocated. >> * min(max(max(VM_KMEM_SIZE, Physical memory/VM_KMEM_SIZE_SCALE), >> * VM_KMEM_SIZE_MIN), VM_KMEM_SIZE_MAX) >> * is the total KVA space allocated for kmem_map. >> */ >> >>>> vfs.zfs.arc_max=409715200 >>>> (That's 400M, 400M and 40M, respectively.) >>>> Stupid question, perhaps, but is vm.kmem_size/vm.kmem_size_max limited by >>>> physical RAM? >>> Yes. >>> >> To be precise, it's actually limited by 2 * sizeof(physical RAM). >> It's still size of a _virtual_ memory map (kmem_map), after all: >> >> : /* >> : * Limit kmem virtual size to twice the physical memory. >> : * This allows for kmem map sparseness, but limits the size >> : * to something sane. Be careful to not overflow the 32bit >> : * ints while doing the check. >> : */ >> : if (((vm_kmem_size / 2) / PAGE_SIZE) > cnt.v_page_count) >> : vm_kmem_size = 2 * cnt.v_page_count * PAGE_SIZE; > > Well OK, but that seems pretty dangerous, because it leaves open a pathway to > exhaust all of physical memory and presumably panic. is KVA pageable? Is the kmem_map dedicating non-pageable memory? I've set my vm.kmem_max to 1G, (on a 4G amd64 box). Is that reasonable? LER > > Kris > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 512-248-2683 E-Mail: ler@lerctr.org US Mail: 430 Valona Loop, Round Rock, TX 78681-3893