Messages in this thread | | | Date | Tue, 17 Mar 2009 15:35:32 -0400 | From | Mathieu Desnoyers <> | Subject | Re: cli/sti vs local_cmpxchg and local_add_return |
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* David Miller (davem@davemloft.net) wrote: > From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> > Date: Tue, 17 Mar 2009 12:06:35 -0400 > > > But powerpc has non-maskable interrupts, so for less than 4 cycles, I > > think it's better to stay with the local_t variant to be NMI-safe. > > Sparc64 has non-maskable interrupts too btw. >
OK, this alone is a strong argument to favor NMI-safe lockless algorithm even if it is a bit slower. We should see what kind of performance impact it has on overall tracing performance to find out if it will make a measurable difference anyway.
Mathieu
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