Messages in this thread | | | Subject | Re: [RFC v5 01/11] mm: Dont assume page-table invariance during faults | From | Laurent Dufour <> | Date | Tue, 8 Aug 2017 14:11:44 +0200 |
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On 08/08/2017 11:45, Anshuman Khandual wrote: > On 06/16/2017 11:22 PM, Laurent Dufour wrote: >> From: Peter Zijlstra <peterz@infradead.org> >> >> One of the side effects of speculating on faults (without holding >> mmap_sem) is that we can race with free_pgtables() and therefore we >> cannot assume the page-tables will stick around. >> >> Remove the relyance on the pte pointer. > > Looking into other parts of the series, it seemed like now we have > sequence lock both at MM and VMA level but then after that we still > need to take page table lock before handling page faults (in turn > manipulating PTE which includes swap in paths as well). Is not that > true ?
Page table locking is still required as several VMAs can reference the same page table.
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