Re: [PATCH bpf-next 0/6] workqueue: introduce BPF iterators for workqueues, worker pools and pending work

Hello,

On Tue, Jul 28, 2026 at 02:55:19PM +0800, Imran Khan wrote:
> Nearly every subsystem defers work to workqueues, and their state can
> already be observed on a live system, just not at a granularity that is
> convenient to consume. sysrq dumps every workqueue and pool to the kernel
> log in a fixed format, with no way to select or aggregate; the WQ_SYSFS
> interface only covers workqueues that ask for it and exposes attributes
> rather than runtime state; and the drgn scripts under tools/workqueue/ need
> a debuginfo-equipped userspace and read the state from the outside, without
> the locks that protect it.
> 
> This series adds BPF iterators for workqueues, worker pools and pending
> work items, so that this state can be walked from inside the kernel, under
> the right locking, with filtering and aggregation done in place and only
> the interesting part copied to userspace.

I'm not necessarily against it but what are the use cases here? If for
debugging, isn't drgn + hooking into tracepoints mostly enough? Can you give
concrete examples where bpf iterators are essential?

Thanks.

-- 
tejun