Freebsd 8.0 kmem map too small

[Alexander V. Ribchansky]

12.05.2010 01:38, Pawel Jakub Dawidek пишет:
> -skip-
> Could you try the following patch without disabling UMA?
>
> 	http://people.freebsd.org/~pjd/patches/vfs_subr.c.7.patch
>
> It works quite well for me.
>
> Also we still don't have back-pressure mechanism when arc_meta_limit is
> exceeded. OpenSolaris frees namecache entires then and we currently do
> nothing. I'll experiment with a bit and let you know if the patch above
> doesn't fix your problem still.
>
>    

I apply you patch on today's STABLE. with 2Gb of ram
m.kmem_size_max: 1073741824
vm.kmem_size_min: 0
vm.kmem_size: 1073741824

hw.physmem: 2125430784
hw.usermem: 1291554816
hw.realmem: 2146959360

vfs.zfs.arc_max: 268435456

it survive two sequent buildworld & buildkernel. Wired memory is 791M. 
Without UMA Wired memory was around 500M on THE SAME settings.
Could you please explain as for nOOb, what we get with UMA, and why it 
uses MORE Wired memory? Is it for better perfomance or for what? What is 
your recomended tuning for i386 FreeBSD-8 on 2Gb ram typical desktop?

And.. again, thank you for your great work on ZFS!! You are MONSTER! :)

--
     AVR39-RIPE