On Thu, Feb 13, 2014 at 4:25 AM, Paolo Bonzini <pbonz...@redhat.com> wrote: > Il 13/02/2014 10:11, Alex Bligh ha scritto: >> >> I'll certainly have a look through this. However before I do, what >> problem is this trying to solve? Do we think there is possibility >> of contention on the active timers lock? I used to think this was >> taken (let alone contented) relatively infrequently, but Rob Herring's >> recent email suggests to me the list is being modified in some >> circumstances rather more frequently than I thought. > > I think that, more than contention, it tries to reduce the cost of > synchronization primitives, especially the locking and unlocking of the list > around the invocation of timer callbacks.
Yes, the assumption is that the active timers are a read-mostly list, so rcu is a win. Mike
