Re: [PATCH] perf/x86/intel/uncore: Fix client IMC events return huge result

[Sasha Levin]

On Fri, Nov 16, 2018 at 05:19:45AM -0800, kan.liang@xxxxxxxxxxxxxxx wrote:
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> The client IMC bandwidth events return very huge result.
>  perf stat -e uncore_imc/data_reads/ -e uncore_imc/data_writes/ -I
> 10000 -a
>  10.000117222 34,788.76 MiB uncore_imc/data_reads/
>  10.000117222 8.26 MiB uncore_imc/data_writes/
>  20.000374584 34,842.89 MiB uncore_imc/data_reads/
>  20.000374584 10.45 MiB uncore_imc/data_writes/
>  30.000633299 37,965.29 MiB uncore_imc/data_reads/
>  30.000633299 323.62 MiB uncore_imc/data_writes/
>  40.000891548 41,012.88 MiB uncore_imc/data_reads/
>  40.000891548 6.98 MiB uncore_imc/data_writes/
>  50.001142480 1,125,899,906,621,494.75 MiB uncore_imc/data_reads/
>  50.001142480 6.97 MiB uncore_imc/data_writes/
>
> The client IMC events are freerunning counters. They still use the
> old event encoding format (0x1 for data_read and 0x2 for data write).
> The counter bit width is calculated by common code, which assume that
> the standard encoding format is used for the freerunning counters.
> Error bit width information is calculated.
>
> The event->attr.config, which directly from user space, should not be
> used by the functions of freerunning counters.
> For client IMC events, the attr.config needs to be converted to the
> standard encoding format. The modified event config will be stored in
> event->hw.config.
> For other freerunning counters, the attr.config has the correct format.
> Just save it in event->hw.config.
> Using event->hw.config to replace event->attr.config for the functions
> of freerunning counters.
>
> Fix: commit 9aae1780e7e8 ("perf/x86/intel/uncore: Clean up client IMC
> uncore")

Please use a "fixes" (vs "fix") tag here, a few folks have automation
around this. It should look something like this:

	Fixes: commit 9aae1780e7e8 ("perf/x86/intel/uncore: Clean up client IMC uncore")

Also, if you intend for this to go in stable trees, please add a stable
tag rather than just cc it to the stable mailing list. Something like
this:

	Cc: stable@xxxxxxxxxx

--
Thanks,
Sasha