Re: [PATCH v4 0/3] selftests: cgroup: Enhance robustness with polling helpers

On Mon, Nov 24, 2025 at 08:38:13PM +0800, Guopeng Zhang wrote:

Hi all,

This patch series introduces improvements to the cgroup selftests by adding helper functions to better handle asynchronous updates in cgroup statistics. These changes are especially useful for managing cgroup stats like memory.stat and cgroup.stat, which can be affected by delays (e.g., RCPU callbacks and asynchronous rstat flushing).

v4:

• Patch 1/3: Adds the `cg_read_key_long_poll()` helper to poll cgroup keys with retries and configurable intervals.
• Patch 2/3: Updates `test_memcg_sock()` to use `cg_read_key_long_poll()` for handling delayed "sock" counter updates in memory.stat.
• Patch 3/3: Replaces `sleep` and retry logic in `test_kmem_dead_cgroups()` with `cg_read_key_long_poll()` for waiting on `nr_dying_descendants`.

Michal, if this looks good to you, I'll apply after the merge window.

Thanks.