Hi, Tejun Thanks for the review comments. > > Add dmem.events to report hierarchical low/max event counts per DMEM > > region. Increment counters on dmem.max allocation failures and > > dmem.low protection events. The file is available for non-root cgroups > > only. > > Please don't double space in descs or comments. Also, maybe it's obvious but > it'd help if you list why and how this is useful. Why do we want to add > this?
I'll fix the double spacing in the commit message and comments. As for the motivation: dmem already exposes per-region limits and current usage, but not how often those limits actually matter at runtime. Without event counters, it's hard to tell whether allocation failures come from this cgroup, a parent limit, or pressure elsewhere in the hierarchy. dmem.events provides that visibility for tuning dmem.low/dmem.max and diagnosing recurring device memory pressure. I'll expand the commit message to cover this. > > + dmem.events > > + A read-only file that reports the number of times each cgroup > > + has hit its configured memory limits. The format lists each > > + region on a single line, followed by the event counters:: > > + > > + drm/0000:03:00.0/vram0 low 0 max 3 > > + drm/0000:03:00.0/stolen low 0 max 0 > > This isn't a supported file format. Please read the documentation on allowed > formats. Thanks for catching this. I'll switch dmem.events to nested-keyed format (region low=N max=M). Thanks again for the valuable feedback. Best regards, Hongfu
