Re: VFS scalability

From: Nick Piggin
Date: Mon Jun 27 2005 - 03:07:15 EST


Andi Kleen wrote:
On Mon, Jun 27, 2005 at 05:33:43PM +1000, Nick Piggin wrote:

Maybe adding a prefetch for it at the beginning of sys_read() might help, but then with 64CPUs writing to parts of the inode
it will always thrash no matter how many prefetches.


True. I'm just not sure what is causing the bouncing - I guess
->f_count due to get_file()?


That's in the file, not in the inode. It must be some inode field.
I don't know which one.


Oh yes, my mistake.

There is probably some oprofile/perfmon event that could tell
you which function dirties the cacheline.


I'll see if I can work it out. Thanks.

--
SUSE Labs, Novell Inc.

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