Messages in this thread | | | Subject | Re: [PATCH 26/31] sched, numa, mm: Add fault driven placement and migration policy | From | Peter Zijlstra <> | Date | Fri, 26 Oct 2012 16:11:12 +0200 |
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On Fri, 2012-10-26 at 15:50 +0200, Ingo Molnar wrote: > > Oh, just found the reason: > > the ptep_modify_prot_start()/modify()/commit() sequence is > SMP-unsafe - it has to be done under the mmap_sem write-locked. > > It is safe against *hardware* updates to the PTE, but not safe > against itself.
Shouldn't the pte_lock serialize all that still? All sites that modify PTE contents should hold the pte_lock (and do afaict).
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