Re: [RFC PATCH 3/6] selftests/damon/_damon_sysfs: implement DamonProbes

On Wed, 29 Jul 2026 15:04:39 +0000 [email protected] wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The error result of `write_file()` for setting the probe weight is silently discarded.
> --
> 
> --- Patch [3]: [RFC PATCH 3/6] selftests/damon/_damon_sysfs: implement DamonProbes ---
> commit 12ef2c079bfc3ec5e9f25fc085e18c6bca931488
> Author: SJ Park <[email protected]>
> 
> selftests/damon/_damon_sysfs: implement DamonProbes
> 
> Extend _damon_sysfs.py to support staging and committing DAMON probes.
> It will be used for setting DAMON probes via sysfs changes for testing
> purposes.
> 
> > diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py
> > --- a/tools/testing/selftests/damon/_damon_sysfs.py
> > +++ b/tools/testing/selftests/damon/_damon_sysfs.py
> 
> [ ... ]
> 
> > +class DamonProbe:
> > +    weight = None
> > +    filters = None
> > +    probes = None
> > +    idx = None
> > +
> > +    def __init__(self, weight=0, filters=None):
> > +        self.weight = weight
> > +        if filters is None:
> > +            filters = DamonFilters()
> > +        self.filters = filters
> > +        self.filters.probe = self
> > +
> > +    def sysfs_dir(self):
> > +        return os.path.join(self.probes.sysfs_dir(), '%d' % self.idx)
> > +
> > +    def stage(self):
> > +        err = write_file(
> > +                os.path.join(self.sysfs_dir(), 'weight'), '%d' % self.weight)
> > +        return self.filters.stage()
> 
> [Severity: Medium]
> Is err intentionally ignored here? If write_file() fails to write the weight
> to sysfs, it returns an error string. Returning self.filters.stage() directly
> without checking err will swallow the error and might cause tests to proceed
> with incorrect assumptions about the probe configuration.
> 
> Should this check err before returning, similar to how it is handled in other
> stage() methods?

Good catch, I will fix.
'
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=3
> 


Thanks,
SJ