[ofa-general] Re: [PATCH] mmu notifiers #v7

Andrea Arcangeli andrea at qumranet.com
Fri Feb 29 05:09:05 PST 2008


On Thu, Feb 28, 2008 at 05:03:01PM -0800, Christoph Lameter wrote:
> I thought you wanted to get rid of the sync via pte lock?

Sure. _notify is happening inside the pt lock by coincidence, to
reduce the changes to mm/* as long as the mmu notifiers aren't
sleep capable.

> What changes to do_wp_page do you envision?

Converting it to invalidate_range_begin/end.

> What is the trouble with the current do_wp_page modifications? There is 
> no need for invalidate_page() there so far. invalidate_range() does the 
> trick there.

No trouble, it's just that I didn't want to mangle over the logic of
do_wp_page unless it was strictly required, the patch has to be
obviously safe. You need to keep that bit of your patch to make the
mmu notifiers sleepable.



More information about the general mailing list