Subject: Re: linux-next: build failure after merge of the perf tree

From: James Clark <[email-masked]>
Date: Mon, 19 Jan 2026 16:37:12 +0000

On 19/01/2026 4:09 pm, Mark Brown wrote:
> Hi all,
> 
> After merging the perf tree, today's linux-next build (arm64 perf)
> failed like this:
> 
> Exception processing /tmp/next/perf/pmu-events/arch/arm64/arm/cortex-a510/pmu.json

Hi Mark,

Do you have a clean checkout? a66f6242fbf52 removes this file and at the 
same time removes the definition from common-and-microarch.json. I think 
you would get this build error if cortex-a510/pmu.json exists as a stale 
file with that commit applied.

Thanks
James

> Traceback (most recent call last):
>    File "/tmp/next/build/tools/perf/pmu-events/jevents.py", line 1405, in ftw
>      action(parents, item)
>      ~~~~~~^^^^^^^^^^^^^^^
>    File "/tmp/next/build/tools/perf/pmu-events/jevents.py", line 656, in preprocess_one_file
>      for event in read_json_events(item.path, topic):
>                   ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
>    File "/tmp/next/build/tools/perf/pmu-events/jevents.py", line 464, in read_json_events
>      events = json.load(open(path), object_hook=JsonEvent)
>    File "/usr/lib/python3.13/json/__init__.py", line 293, in load
>      return loads(fp.read(),
>          cls=cls, object_hook=object_hook,
>          parse_float=parse_float, parse_int=parse_int,
>          parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
>    File "/usr/lib/python3.13/json/__init__.py", line 359, in loads
>      return cls(**kw).decode(s)
>             ~~~~~~~~~~~~~~~~^^^
>    File "/usr/lib/python3.13/json/decoder.py", line 345, in decode
>      obj, end = self.raw_decode(s, idx=_w(s, 0).end())
>                 ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
>    File "/usr/lib/python3.13/json/decoder.py", line 361, in raw_decode
>      obj, end = self.scan_once(s, idx)
>                 ~~~~~~~~~~~~~~^^^^^^^^
>    File "/tmp/next/build/tools/perf/pmu-events/jevents.py", line 422, in __init__
>      raise argparse.ArgumentTypeError('Cannot find arch std event:', arch_std)
> argparse.ArgumentTypeError: ('Cannot find arch std event:', 'PMU_OVFS')
> 
> Caused by commit
> 
>     a66f6242fbf52 (perf vendor events arm64: Remove uncountable events)
> 
> I have used the perf tree from 20260116 instead.