Messages in this thread | | | Date | Wed, 23 Nov 2011 08:12:03 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH 1/2] trace_events_filter: use rcu_assign_pointer() when setting ftrace_event_call->filter |
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On Wed, Nov 23, 2011 at 08:06:53AM -0800, Tejun Heo wrote: > otherwise, it may fetch the old values from before the new area is > initialized on archs where data dependency barrier isn't noop.
I think this can be a problem on archs where dd barrier is noop but wmb is not. dd barrier is implied on every read access but nothing guarantees the updating CPU sends out write for the pointer assignment before initialization of the new area.
Thanks.
-- tejun
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