On 5/31/21 1:33 PM, Michal Hocko wrote:

On Thu 20-05-21 15:29:01, Aaron Tomlin wrote:

quoted

A customer experienced a low-memory situation and decided to issue a
SIGKILL (i.e. a fatal signal). Instead of promptly terminating as one
would expect, the aforementioned task remained unresponsive.

Further investigation indicated that the task was "stuck" in the
reclaim/compaction retry loop. Now, it does not make sense to retry
compaction when a fatal signal is pending.

Is this really true in general? The memory reclaim is retried even when
fatal signals are pending. Why should be compaction different? I do
agree that retrying way too much is bad but is there any reason why this
special case doesn't follow the max retry logic?

Compaction doesn't do anything if fatal signal is pending, it bails out
immediately and the checks are rather frequent. So why retry?