Re: [PATCH 0/7] nvme: export additional diagnostic counters via sysfs

Nilay Shroff
2026-02-03T13:03:58Z

On 2/3/26 5:56 PM, Ming Lei wrote:
> On Sat, Jan 31, 2026 at 2:22 AM Nilay Shroff <nilay@linux.ibm.com> wrote:
>>
>> Hi,
>>
>> The NVMe driver encounters various events and conditions during normal
>> operation that are either not tracked today or not exposed to userspace
>> via sysfs. Lack of visibility into these events can make it difficult to
>
> Not sure if it is true, you may get tons of results by googling `linux
> bpf observe`.
>
Yeah true, and the intent was not to mention/generalize that _no_ NVMe events
being tracked today. The goal of this patchset is to export specific event and
statistic counters that are either not tracked at all or not exposed to userspace
in a consistent way, and that could be useful for analyzing NVMe device and
multipath behavior.
So this patchset proposes to track these counters (command retry, failover, errors,
I/O requeue, controller reset/reconnect etc.) and export via sysfs. These counters
are intended to be consumed by tools such as nvme-cli/nvme-top. For nvme-cli, in
particular, sysfs is currently the only practical and supported interface for
consuming such statistics.
Once these counters exist in the kernel, they can of course also be observed via
BPF if desired. However, the primary motivation here is to make these events
explicitly tracked and reliably available, rather than requiring ad-hoc instrumentation
to infer them.

Thanks,
--Nilay