Messages in this thread | | | Date | Wed, 30 Jan 2008 16:20:35 -0600 | From | Robin Holt <> | Subject | Re: [patch 1/6] mmu_notifier: Core code |
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On Wed, Jan 30, 2008 at 11:19:28AM -0800, Christoph Lameter wrote: > On Wed, 30 Jan 2008, Jack Steiner wrote: > > > Moving to a different lock solves the problem. > > Well it gets us back to the issue why we removed the lock. As Robin said > before: If its global then we can have a huge number of tasks contending > for the lock on startup of a process with a large number of ranks. The > reason to go to mmap_sem was that it was placed in the mm_struct and so we > would just have a couple of contentions per mm_struct. > > I'll be looking for some other way to do this.
I think Andrea's original concept of the lock in the mmu_notifier_head structure was the best. I agree with him that it should be a spinlock instead of the rw_lock.
Thanks, Robin
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