Messages in this thread | | | Subject | Re: [RFC PATCH v1 3/5] KVM: Add paravirt kvm_flush_tlb_others | From | Peter Zijlstra <> | Date | Tue, 01 May 2012 17:36:27 +0200 |
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On Tue, 2012-05-01 at 18:31 +0300, Avi Kivity wrote: > On 05/01/2012 05:59 PM, Peter Zijlstra wrote: > > On Tue, 2012-05-01 at 15:12 +0300, Avi Kivity wrote: > > > local_irq_save() is a stronger version or rcu_read_lock() > > > > Not so, local_irq_save() doesn't at all stop regular RCU grace periods, > > things like preemptible rcu can be driven from rcu_read_unlock(). > > > > Note that this is the reason call_rcu_sched() exists and is used in this > > case. > > Ah, thanks for the correction. I'll read some more about the _sched > variants.
Basically:
rcu_read_{,un}lock_sched() -- aka preempt_{en,dis}able() call_rcu_sched() synchronize_rcu_sched() -- aka synchronize_sched();
Define an RCU variant where each cpu has to have scheduled at least once to complete a grace period.
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