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    SubjectRe: [PATCH 1 of 9] Lock the entire mm to prevent any mmu related operation to happen
    On Thu, 17 Apr 2008, Andrea Arcangeli wrote:

    > Also note, EMM isn't using the clean hlist_del, it's implementing list
    > by hand (with zero runtime gain) so all the debugging may not be
    > existent in EMM, so if it's really a mm_lock race, and it only
    > triggers with mmu notifiers and not with EMM, it doesn't necessarily
    > mean EMM is bug free. If you've a full stack trace it would greatly
    > help to verify what is mangling over the list when the oops triggers.

    EMM was/is using a single linked list which allows atomic updates. Looked
    cleaner to me since doubly linked list must update two pointers.

    I have not seen docs on the locking so not sure why you use rcu
    operations here? Isnt the requirement to have either rmap locks or
    mmap_sem held enough to guarantee the consistency of the doubly linked list?

     \ /
      Last update: 2008-04-17 21:13    [W:0.019 / U:14.664 seconds]
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