Re: [PATCH v2 4/4] perf/x86/uncore: modularize Intel uncore driver

From: Ingo Molnar
Date: Thu Apr 24 2014 - 04:14:25 EST



* Stephane Eranian <eranian@xxxxxxxxxx> wrote:

> >> Most of the codes without comments are hardware specific codes.
> >> The corresponding contents in Intel uncore documents are big
> >> tables/lists, nothing tricky/interesting. I really don't know how
> >> to comment these code.
> >
> > Have a look at other PMU drivers, such as
> > arch/x86/kernel/cpu/perf_event_intel_rapl.c, which begin with a
> > general explanation attached below.
>
> I think a more useful modularization would be to split that huge
> file (perf_event_intel_uncore.c) into smaller files like we do for
> the core PMU. There is just too much stuff in this file for my own
> taste. Hard to navigate and I spend quite some time looking at it
> and modifying it!
>
> You could follow the model of the core PMU support files.
> You'd have a "core" file with the common routines, and then
> a file perf processor:
> - perf_event_intel_uncore.c
> - perf_event_intel_snbep_uncore.c
> - perf_event_intel_nhmex_uncore.c
> - perf_event_intel_ivt_uncore.c
> - ...
>
> Each processor specific module, would be a kernel module. The core
> could be one too. Note that this would not alleviate the need for
> some basic descriptions at the beginning of each file outlining the
> PMU boxes exported to a minimum.

This structure you outline sounds like a good first step, I like it.

To simplify this restructuring, initially we could even keep the core
uncore bits in the core (ha!), to not have module-on-module
dependencies.

Thanks,

Ingo
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