Li, Aubrey wrote: > On Friday, November 30, 2007 8:10 AM, tesla-dev-bounces at opensolaris.org > wrote: > > >> In the PowerTOP repository, the probe that fires when (on x86) >> the halt >> (or mwait) instruction >> is invoked is "cstate_transition". That's appropriate for x86, but >> i'd like to come up with a probe name that would be appropriate >> across both SPARC and x86. >> > > C-state driver will let the processor go into deeper c-state. >
I was thinking would use the existing mwait code path to bring the processor into the deeper c-states? ...or are you suggesting that the c-state driver would contain code that is invoked out of that path? > I knew nothing about SPARC, if it doesn't support the similar deeper > idle state. > I'm afraid there have to be some probes specific for x86. > Some SPARC processors support something similar to a "halt" instruction. On sun4v, this is actually executed by the hypervisior (and the guest simply "yields" to the hypervisor, rather than invoking the "halt" instruction directly. On sun4u, the OPL systems support a "halt" like instruction as well...although like I said I'm unsure whether it helps bring the processor into a lower power consuming state. Thanks, -Eric
