Re: changing mm->mmap_sem (was: Re: system call for process

[Linus Torvalds]

On Sun, 18 Mar 2001, Rik van Riel wrote:
>
> Indeed, having threaded apps do multiple page faults at the
> same time is the main goal of this patch. However, I don't
> see how it would be good for scalability to have multiple
> threads fault in the same page at the same time, when they
> could just wait for one of them to do the work.

But they will.

That's what lock_page() etc are there for - there's no need for the VM to
synchronize because we already have the synchronization primitives at a
lower level.

And there isn't any other lock that could work anyway. It's either the
whole MM or a page. There's nothing in between.

		Linus