Re: fast path for anonymous memory allocation

Nick Piggin
2004-11-19T02:19:11Z

Christoph Lameter wrote:
> This patch conflicts with the page fault scalability patch but I could not
> leave this stone unturned. No significant performance increases so
> this is just for the record in case someone else gets the same wild idea.
>

I had a similar wild idea. Mine was to just make sure we have a spare
per-CPU page ready before taking any locks.

Ahh, you're doing clear_user_highpage after the pte is already set up?
Won't that be racy? I guess that would be an advantage of my approach,
the clear_user_highpage can be done first (although that is more likely
to be wasteful of cache).