Re: Slow vmalloc in 2.6.35-rc3

From: Avi Kivity
Date: Sun Jun 27 2010 - 05:18:04 EST

On 06/24/2010 06:14 PM, Nick Piggin wrote:
On Thu, Jun 24, 2010 at 12:19:32PM +0300, Avi Kivity wrote:
I see really slow vmalloc performance on 2.6.35-rc3:
Can you try this patch?

The patch completely eliminates the problem.

It seems completely wrong - iterating 8 levels of a binary tree
shouldn't take half a millisecond.
It's not iterating down the tree, it's iterating through the
nodes to find a free area. Slows down because lazy vunmap means
that quite a lot of little areas build up right at the start of
our search start address. The vmap cache should hopefully fix
it up.

I see, thanks.

error compiling committee.c: too many arguments to function

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