We noticed the kworker in page_pool_release_retry() was waken
up repeatedly and infinitely in production because of the
buggy driver causing the inflight less than 0 and warning
us in page_pool_inflight()[1].
Since the inflight value goes negative, it means we should
not expect the whole page_pool to get back to work normally.
This patch mitigates the adverse effect by not rescheduling
the kworker when detecting the inflight negative in
page_pool_release_retry().
[1]
[Mon Feb 10 20:36:11 2025] ------------[ cut here ]------------
[Mon Feb 10 20:36:11 2025] Negative(-51446) inflight packet-pages
...
[Mon Feb 10 20:36:11 2025] Call Trace:
[Mon Feb 10 20:36:11 2025] page_pool_release_retry+0x23/0x70
[Mon Feb 10 20:36:11 2025] process_one_work+0x1b1/0x370
[Mon Feb 10 20:36:11 2025] worker_thread+0x37/0x3a0
[Mon Feb 10 20:36:11 2025] kthread+0x11a/0x140
[Mon Feb 10 20:36:11 2025] ? process_one_work+0x370/0x370
[Mon Feb 10 20:36:11 2025] ? __kthread_cancel_work+0x40/0x40
[Mon Feb 10 20:36:11 2025] ret_from_fork+0x35/0x40
[Mon Feb 10 20:36:11 2025] ---[ end trace ebffe800f33e7e34 ]---
Note: before this patch, the above calltrace would flood the
dmesg due to repeated reschedule of release_dw kworker.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250214064250.85987-1-kerneljasonxing@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
43130d02ba