Re: page fault fastpath: Increasing SMP scalability by introducing

Andi Kleen
2004-08-15T23:53:09Z

Christoph Lameter <clameter@sgi.com> writes:

> On Sun, 15 Aug 2004, David S. Miller wrote:
>
>>
>> Is the read lock in the VMA semaphore enough to let you do
>> the pgd/pmd walking without the page_table_lock?
>> I think it is, but just checking.
>
> That would be great.... May I change the page_table lock to
> be a read write spinlock instead?

That's probably not a good idea. r/w locks are extremly slow on
some architectures. Including ia64.

Just profile cat /proc/net/tcp on a machine with a lot of memory
and you'll notice.

-Andi