Date: Wed, 7 Mar 2012 11:31:09 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Luke Marsden <luke@hybrid-logic.co.uk> Cc: freebsd-fs@freebsd.org, Ian Lepore <freebsd@damnhippie.dyndns.org>, team@hybrid-logic.co.uk Subject: Re: FreeBSD 8.2 - active plus inactive memory leak!? Message-ID: <20120307093109.GF75778@deviant.kiev.zoral.com.ua> In-Reply-To: <1331112366.2589.51.camel@pow> References: <1331061203.2218.38.camel@pow> <4F569DFF.8040807@mac.com> <1331080581.2589.28.camel@pow> <20120307082338.GD75778@deviant.kiev.zoral.com.ua> <1331112366.2589.51.camel@pow>
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[-- Attachment #1 --] On Wed, Mar 07, 2012 at 09:26:06AM +0000, Luke Marsden wrote: > On Wed, 2012-03-07 at 10:23 +0200, Konstantin Belousov wrote: > > On Wed, Mar 07, 2012 at 12:36:21AM +0000, Luke Marsden wrote: > > > I'm trying to confirm that, on a system with no pages swapped out, that > > > the following is a true statement: > > > > > > a page is accounted for in active + inactive if and only if it > > > corresponds to one or more of the pages accounted for in the > > > resident memory lists of all the processes on the system (as per > > > the output of 'top' and 'ps') > > No. > > > > The pages belonging to vnode vm object can be active or inactive or cached > > but not mapped into any process address space. > > Thank you, Konstantin. Does the number of vnodes we've got open on this > machine (272011) fully explain away the memory gap? > > Memory gap: > 11264M active + 2598M inactive - 9297M sum-of-resident = 4565M > > Active vnodes: > vfs.numvnodes: 272011 > > That gives a lower bound at 17.18Kb per vode (or higher if we take into > account shared libs, etc); that seems a bit high for a vnode vm object > doesn't it? Vnode vm object keeps the set of pages belonging to the vnode. There is nothing bad (or good) there. > > If that doesn't fully explain it, what else might be chewing through > active memory? > > Also, when are vnodes freed? > > This system does have some tuning... > kern.maxfiles: 1000000 > vm.pmap.pv_entry_max: 73296250 > > Could that be contributing to so much active + inactive memory (5GB+ > more than expected), or do PV entries live in wired e.g. kernel memory? pv entries are accounted as wired memory. > > > On Tue, 2012-03-06 at 17:48 -0700, Ian Lepore wrote: > > In my experience, the bulk of the memory in the inactive category is > > cached disk blocks, at least for ufs (I think zfs does things > > differently). On this desktop machine I have 12G physical and > > typically have roughly 11G inactive, and I can unmount one particular > > filesystem where most of my work is done and instantly I have almost > > no inactive and roughly 11G free. > > Okay, so this could be UFS disk cache, except the system is ZFS-on-root > with no UFS filesystems active or mounted. Can I confirm that no > double-caching of ZFS data is happening in active + inactive (+ cache) > memory? ZFS double-buffers the mmaped files. [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk9XKt0ACgkQC3+MBN1Mb4jA/ACg86XbRffmpRAUBECh0y9DGiz5 GNgAoLXNzE8YTJ/lX70JieLwe0CDm9UQ =2dBb -----END PGP SIGNATURE-----home | help
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