Messages in this thread | | | Date | Mon, 26 Jun 2006 13:10:53 -0400 | From | William Cohen <> | Subject | Re: [Perfctr-devel] [perfmon] 2.6.17.1 new perfmon code base, libpfm, pfmon available |
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Stephane Eranian wrote: > Will, > > On Fri, Jun 23, 2006 at 05:13:47PM -0400, William Cohen wrote: > >>Hi Stephane, >> >>Some quick questions about the current perfmon code. >> >> >>The athlon has very similar hw to the amd64 and there is now 32-bit >>x86-64 support. Wouldn't it make sense to move perfmon_amd.c to i386 >>and have it work in the same way as perfmon_p4.c does currently for p4 >>and em64t? >> > > Does Athlon have 4 counters as well. I don't have the HW so I cannot really > test. I suspect they are similar. If you have HW and you can test, I don't > have a problem.
I have an Athlon machine in the office that I can test this change out on and send you a diff.
>>Could the 32-bit and 64-bit code be combined in a manner similar to >>oprofile and avoid duplication between perfmon_em64t_pebs.c and >>perfmon_p4_pebs.c? pfm_{p4|em64}_ds_area and >>pfm_{p4|em64t}_pebs_sample_entry have differences due to the upgrade >>from 32 to 64 bit values. >> > > You have several issues here: > - the 64-bit version has 8 more reigsters int the PEBS entry > - the PEBS entry uses 32 or 64 bitfields depending on data model > - the ds_area uses 32 or 64 bits depending on the data model except for the threshold value > > Now remember that on on EM64T we also support 32-bit (i386) binaries. > With an EM64T kernel you would have the 64-bit PEBS format. With the same UUID if would satisfy > a i386 binary and this is wrong because they would not match the definition of the PEBS entry. > We need to keep the PEBS 32 and 64-bit format UUIDs different. At the source code level, you would > need to ifdef __x86_64__ and __i386__ to switch struct definition and UUID. That's doable but is > this clean?
Certainly given the differences in the pebs elements there will need to unique names for each. It was just a thought to factor out the similar code.
There is support to handle amd64 hardware running on 32-bit kernel. Has someone verified that the em64t processor generate 32-bit compatible entries when running in 32-bit mode? Or does it always write out 64-bit style PEBS entries?
>>Why isn't Intel family 0xf model 3 not supported? >> Model 1,2, 4, and 5 are supported. >> Model 3 Pentium4 isn't that different is it? > > > I have not looked at this. I don't have a lot of P4 HW. I think that > all family 15 uses the same PMU. Could someone confirm this?
A NC State University professor mentioned that the ommission of model 3 was a problem because his machine were model 3. I suggested the addition of case for model 3 processors to get him going on that.
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