Messages in this thread | | | Date | Wed, 20 Feb 2008 16:34:09 +0100 | From | Andrea Arcangeli <> | Subject | Re: [PATCH] mmu notifiers #v6 |
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On Wed, Feb 20, 2008 at 08:41:55AM -0600, Robin Holt wrote: > On Wed, Feb 20, 2008 at 11:39:42AM +0100, Andrea Arcangeli wrote: > > XPMEM simply can't use RCU for the registration locking if it wants to > > schedule inside the mmu notifier calls. So I guess it's better to add > > Whoa there. In Christoph's patch, we did not use rcu for the list. It > was a simple hlist_head. The list manipulations were done under > down_write(¤t->mm->mmap_sem) and would therefore not be racy. All > the callout locations are already acquiring the mmap_sem at least > readably, so we should be safe. Maybe I missed a race somewhere.
You missed quite a few, see when atomic=1 and when mmu_rmap_notifier is invoked for example.
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