Messages in this thread | | | Date | Wed, 18 Jun 2008 22:03:43 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction |
| |
Benjamin Herrenschmidt wrote: > On Wed, 2008-06-18 at 17:24 -0700, Linus Torvalds wrote: > >> On Wed, 18 Jun 2008, Jeremy Fitzhardinge wrote: >> >>> Along the lines of: >>> >> Hell no. There's a reason we have a special set_wrprotect() thing. We can >> do it more efficiently on native hardware by just clearing the bit >> atomically. No need to do the cmpxchg games. >> > > But we can't batch ... >
Which architecture are you interested in? If it isn't x86, you can probably get anything past Linus ;)
I'll do some measurements to see what effect the batchable ptep_set_wrprotect() has on native. If it's significant, I'll propose making it conditional on CONFIG_PARAVIRT.
J
| |