On Thu, Jul 06, 2006 at 09:19:30AM -0700, Siddha, Suresh B wrote: > On Thu, Jul 06, 2006 at 08:01:18AM -0700, Stephane Eranian wrote: > > Hello, > > > > > > In the context of the perfmon2 subsystem for processor with HyperThreading, > > we need to know on which thread we are currently running. This comes from > > the fact that the performance counters are shared between the two threads. > > > > We use the thread id (smt_id) because we split the counters in half > > between the two threads such that two threads on the same core can run > > with monitoring on. We are currently computing the smt_id from the > > apicid as returned by a CPUID instruction. This is not very efficient. > > > > I looked through the i386 code and could not find a function nor > > structure that would return this smt_id. In the cpuinfo_x86 structure > > there is an apicid field that looks good, yet it does not seem to be > > initialized nor used. > > > > Is cpuinfo_x86->apicid field obsolete? > > If so, what is replacing it? > > In i386, it is getting initialized in generic_identify() in common.c and > it is getting used for example in intel_cacheinfo.c > Well, yes this is exactly what I want, except that it is not compiled for x86_64 so on a HT Xeon in 64-bit I don't get it. Why is that?
-- -Stephane _______________________________________________ perfmon mailing list [email protected] http://www.hpl.hp.com/hosted/linux/mail-archives/perfmon/
