Messages in this thread | | | Date | Thu, 31 Jan 2008 18:26:36 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: [PATCH] mmu notifiers #v5 |
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On Thu, 31 Jan 2008, Robin Holt wrote:
> > Mutex locking? Could you be more specific? > > I think he is talking about the external locking that xpmem will need > to do to ensure we are not able to refault pages inside of regions that > are undergoing recall/page table clearing. At least that has been my > understanding to this point.
Right this has to be something like rw spinlock. Its needed for both GRU/XPmem. Not sure about KVM.
Take the read lock for invalidate operations. These can occur concurrently. (Or a simpler implementation for the GRU may just use a spinlock).
The write lock must be held for populate operations.
Lock can be refined as needed by the notifier driver. F.e. locking could be restricted to certain ranges.
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