Re: REGRESSION: Performance regressions from switching anon_vma->lock to mutex

Andi Kleen
2011-06-15T16:19:48Z

> Good spot that certainly isn't plain .39.

True.

>
> It looks like those (http://marc.info/?l=linux-mm&m=130533041726258) are
> similar to Linus' patch, except Linus takes the hard line that the root

One difference to Linus' patch is that it does batching for both fork+exit.
I suspect Linus' patch could probably too.

But the fork+exit patch only improved things slightly, it's very unlikely to
recover 52%. Maybe the overall locking here needs to be revisited.

And in general it looks like blind conversion from spinlock to mutex
is a bad idea right now.

-Andi