Re: [PATCH 2/7] Simple Performance Counters: x86_64 support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> It is certainly interesting to compare alternative ways of handling the 
> instruction streams by various processors or models of processors.

Well you have to do a lot more work then to handle instable TSCs then.

In particular the frequencies can be different between CPUs, they 
change (which you can catch with cpufreq notifiers) and during the
cpufreq change period they're instable (as in you can't tell for
some time which frequency they're currently running at and they
might be running immediate frequencies) 

The current cycles_2_ns() users avoid this problem by not
using the TSC in this case, but that might not be an option
for you (cpufreq is becoming more and more ubiquitous)

Good luck.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux