Messages in this thread | | | Date | Wed, 18 Jun 2008 16:59:05 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction |
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Benjamin Herrenschmidt wrote: > On Mon, 2008-06-16 at 04:30 -0700, Jeremy Fitzhardinge wrote: > >> The only current user of this interface is mprotect >> > > Do you plan to use it with fork ultimately ? >
Good point, I'd overlooked that. I guess that means using it in ptep_set_wrprotect().
At present the x86 ptep_set_wrprotect() just uses clear_bit on the pte, which is a locked cycle. Is that significantly cheaper than an xchg + set? (Same number of locked operations...)
J
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