Re: Memory usage increased

["Steve O'Hara-Smith" <steve@xxxxxxxxxx>]

On Sat, 8 May 2010 11:08:23 -0700 (PDT)
Matthew Dillon <dillon@apollo.backplane.com> wrote:

> 
> :	I'm running v2.7.2.3.g01603-DEVELOPMENT on a box which I've just
> :upgraded from an AMD64 3200+ single core with 1.5GB of RAM to a Phenom II
> :955 quad core with 4GB of RAM. The usage pattern hasn't changed. Prior to
> :the upgrade the box was using around 250 megs of swap and apparently
> needed :it because it would be swapping in and out. After the upgrade (and
> :modifying the kernel for SMP support and adjusting the ethernet and audio
> :devices) the box is showing around 1.5GB active, 1GB inactive and about
> :600MB between wired, cache and buf. The active and inactive alone would
> :have been enough to run me out of swap on the old box.
> :
> :	How can I find out what is using all the memory, and whether or
> not :anything is astray ?
> :
> :-- 
> :Steve O'Hara-Smith                          |   Directable Mirror Arrays
> 
>     If the box was using 250MB of swap before and ... well how much
>     swap is it using now?  Zero?  Then it is using less memory now.
>     Or, more precisely, it is no longer gratuitously paging stuff out to
>     swap like it did in 2.5

	OK  now I'm getting really puzzled. I've just rebooted to bump the
sound buffer size (which has got rid of pops and beeps playing 24/96
flacs), I've restored all the windows (including firefox with a couple of
tabs open and sylpheed). Top shows fairly normal application memory usage -
a little low for firefox and sylpheed - with use they'll pick up about
100Mb more between them - but the total system usage is *tiny* viz:

Memory: 107M Active, 108M Inact, 307M Wired, 197M Buf, 2734M Free

	But after quarter of an hour of not doing anything but listening to
some music and

Memory: 113M Active, 168M Inact, 303M Wired, 186M Buf, 2673M Free

	It's late - I'm going to leave it overnight (normal nightly actions
including hammer cleanup on a 1TB filesystem plus a backup to DVD of about
3.5GB bzipped tar from selected areas). 

Memory: 1740M Active, 535M Inact, 317M Wired, 29M Cache, 27M Buf, 636M Free
Swap: 1024M Total, 127M Used, 897M Free, 12% Inuse

	That's a *HUGE* jump in active and inactive overnight and nothing
new is happening.

	Now how can I find out what's eating my memory ?

ps -axo vsz |  awk '{s+=$0} END {print s}'
981556

	Only accounts for about a gigabyte and that should be over because
it counts the text areas several times (there's no virtual equivalent of
rsz in our ps).

	If cache and buf were high I wouldb't be worried but it's active
that's going through the roof followed by inactive.

sysctl -a | grep kvm
vm.kvm_free: 268431360
vm.kvm_size: 1073741824

	Does that mean around 750MB in kernel memory usage ? That seems very
high, and even that added to the total process VM comes around 500M short of
accounting for active+inactive.

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
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