Re: [RFC][PATCH 6/8] mm: handle_speculative_fault()

From: Linus Torvalds
Date: Fri Jan 08 2010 - 14:40:15 EST




On Fri, 8 Jan 2010, Andi Kleen wrote:
>
> With 24 CPU threads cheating is very difficult too.

Stop making value judgements in you word choice, like "cheating".

The fact is, the mmap_sem is per-mm, and works perfectly well. Other
locking can be vma-specific, but as already mentioned, it's not going to
_help_, since most of the time even hugely threaded programs will be using
malloc-like functionality and you have allocations not only cross threads,
but in general using the same vma.

Another fact is simply that you shouldn't write your app so that it needs
to do millions of page faults per second.

So this whole "cheating" argument of yours is total bullshit. It bears no
relation to reality.

Linus
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