Hi, While testing the error handling of my uring using postgres branch I just encountered the situation that io_uring_setup() always fails with ENOMEN. It only does so for the user I did the testing on and not for other users. During the testing a few io_uring using processes were kill -9'd and a few core-dumped after abort(). No io_uring using processes are still alive. As the issue only happens to the one uid I suspect that current_user()->locked_mem got corrupted, perhaps after hitting the limit for real. Unfortunately I do not see any way to debug this without restarting. It seems the user wide limit isn't exported anywhere? I found uids_sysfs_init() while grepping around, but it seems that's just a leftover. This happened on 07a56bb875afbe39dabbf6ba7b83783d166863db / 5.8rc5 + 16. I left the machine running for now, in case there's something that can be debugged while running. But I've to restart it in a bit. It took a while to hit this issue, unfortunately. Greetings, Andres Freund
