On Tue, Feb 08, 2005 at 11:54:56AM -0500, Sonny Rao wrote:
> On Tue, Feb 08, 2005 at 03:34:27PM +1100, Dave Chinner wrote:
> <snip>
> > Seeing as you are running 2.6.11-rc3, you're in luck. Nathan's
> > inode hash tweaks were merged into -rc3, so you can increase the
> > size of the inode hash with a mount option. The mount option
> > is "ihashsize", and it specifies the width of the hash table.
> > i.e. `mount -o ihashsize=xxxxx /dev/sdb1 /mntpt`
> >
> > I'm not sure what the default your filesystem will be using, but
> > a maximum of 16*PAGE_SIZE (=64k chains on i386/x86-64) applies to the
> > default setting.
> >
> > If you specify a size this maximum does not apply, but if you
> > specify a value too large memory allocation for the hash will
> > silently fail and the size will be halved repeatedly until the
> > allocation succeeds.
> >
>
>
> Hmm, I've seen this before too running something which resembles
> SPEC-SFS where we have millions of inodes in cache.
>
> I'm guessing that increasing the hash-size will help us here as well?
>
> Sonny
>
> Oprofile and slab Data from kernel 2.6.9
> Machine is a 4-way Power5 box.
Oh yeah, one other minor detail, I have 112 XFS filesystems
mounted. here, not just one big one.
Sonny
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