tree 8c88aa922f1cd1d313025b61dca911b20c5614b9
parent efc1e2c9bcbab73797d7bc214014cb916d6a8eb5
author Rik van Riel <riel@redhat.com> 1423600074 -0500
committer Frederic Weisbecker <fweisbec@gmail.com> 1425912183 +0100

kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest

The host kernel is not doing anything while the CPU is executing
a KVM guest VCPU, so it can be marked as being in an extended
quiescent state, identical to that used when running user space
code.

The only exception to that rule is when the host handles an
interrupt, which is already handled by the irq code, which
calls rcu_irq_enter and rcu_irq_exit.

The guest_enter and guest_exit functions already switch vtime
accounting independent of context tracking. Leave those calls
where they are, instead of moving them into the context tracking
code.

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will deacon <will.deacon@arm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>