While running performance tests with a small buffer pool, I encountered an anomaly where InnoDB would hang because of running out of buffer pool. There would be some actually clean blocks at buf_pool.flush_list.start, but these would be skipped by buf_flush_LRU_list_batch(). The buf_pool.flush_list.end is being trimmed by periodic calls to buf_pool.get_oldest_modification(). I suspect that the entire buf_pool.LRU would be skipped because of being buffer-fixed, latched, or registered in buf_pool.flush_list due to the
This seems to be a 10.6 regression due to
MDEV-26827. MDEV-32050 would make this problem worse by allowing the purge_coordinator_task to buffer-fix a large number of pages.