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Date:   Tue, 4 Apr 2023 16:40:42 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Jonathan Cameron <Jonathan.Cameron@huawei.com>
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Subject: Re: [PATCH 00/32] Add parents to struct pmu -> dev
Message-ID: <2023040423-hungry-cadet-1fc1@gregkh>
References: <20230404134225.13408-1-Jonathan.Cameron@huawei.com>
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In-Reply-To: <20230404134225.13408-1-Jonathan.Cameron@huawei.com>
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On Tue, Apr 04, 2023 at 02:41:53PM +0100, Jonathan Cameron wrote:
> These are the low hanging fruit following GregKH's feedback that
> all the devices registered via perf_pmu_register() should have parents.
> 
> Note that this causes potential ABI breakage.
> 
> It may fall in the category of it isn't breakage if no one notices
> but I can't be certain of that.  Whilst it is arguable that
> no one should be been accessing PMUs except via the event_source
> bus, there was documentation suggesting /sys/devices/ for particular
> PMUs (because it was a shorter path?)
> 
> The first patch is pulled out of the series:
> https://lore.kernel.org/linux-cxl/20230327170247.6968-1-Jonathan.Cameron@huawei.com/
> [PATCH v3 0/5] CXL 3.0 Performance Monitoring Unit support
> 
> In that particular case it is very useful to be able to figure out which
> CXL device the PMU device is associated with and looking at it's parents
> in the device model as shown with ls -lh /sys/bus/event_sources/devices/
> is a very easy way to do this (once it is correctly parented).
> 
> Addressing all the other instances of struct pmu not covered by this series
> is likely to be a more complex discussion but unlikely to have an affect
> on what is proposed here.
> 
> Documentation updates deliberately 'fixed' in separate patches before
> changing the path to highlight that using /sys/bus/event_source/devices
> path is unchanged by this series and that is presumed to be the
> most common way these files are accessed.

For the whole series, looks good:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>