Messages in this thread | | | Date | Fri, 17 Jun 2016 18:03:07 +0800 | From | Huang Rui <> | Subject | Re: [REDO PATCH v7] perf/x86/amd/power: Add AMD accumulated power reporting mechanism |
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On Thu, Jun 16, 2016 at 04:44:20PM -0400, Vince Weaver wrote: > On Thu, 16 Jun 2016, Huang Rui wrote: > > > > 1. In theory this should also work on an amd fam16h model 30h > > > processor too, correct? The current code limits things to fam15h > > > even though the fam16mod30h has all the proper cpuid flags. > > > > > > > I was told this feature would be supported on fam15h 60h, 70h and > > later processors before. Just checked the fam16h model 30h BKDG, yes, > > it should be also supported. But I didn't test that platform, if you > > confirm it works in your side. We can enable it. > > I can confirm I get power readings on my fam16hmod30h board once I apply a > trivial patch to the driver. I'll send the patch in a separate e-mail. >
OK, thanks.
> > PTSC's frequency is about 100Mhz, it shouldn't be overflow. > > That's what I thought. I'm trying to read the value using the /dev/msr > interface from userspace and I get weird results. > > i.e.: > Jx: read 62d299b84 > PTSC MSR: read 72fe92 > > sleep 5ms > > Jy: read 631b453b9 > PTSC MSR: read 46b25 > > this happens about half the time (PTSC going backwards). Though > admittedly the problem could somehow be in the MSR code I'm using. >
Can you try to read the MSR value two times with the same core (rdmsrl_on_cpu)?
Thanks, Rui
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