Re: [COUNTERPATCH] mm: avoid overflowing preempt_count() in mmu_take_all_locks()

Andrea Arcangeli
2010-04-01T16:04:13Z

On Thu, Apr 01, 2010 at 06:51:17PM +0300, Avi Kivity wrote:
> Can we use srcu now instead?

We can always switch to srcu. Switching to srcu is not a noop for all
mmu notifier invalidates only after these locks can schedule. At that
point, so with srcu + mutex in the rmap locks, all the mmu notifier
invalidates can schedule, allowing XPMEM to be synchronous its
invalidates, and making it safe.