I worked with Jan Kara for fanofity10 failed case. And found this unexpected failure is due to 2 NUMA node, and drop_caches should keep reclaiming on all nodes. I reported this issue and narrow down this issue with Jan Kara by email commnunication. Jan Kara fixed patch link: https://lore.kernel.org/linux-mm/20221115123255.12559-1-jack@suse.cz/ Thanks! BR.