On 11/9/21 4:24 PM, Jens Axboe wrote: > On 11/9/21 3:58 PM, Daniel Black wrote: >>> On Sat, Oct 30, 2021 at 6:30 PM Salvatore Bonaccorso <carnil@xxxxxxxxxx> wrote: >>>> Were you able to pinpoint the issue? >> >> While I have been unable to reproduce this on a single cpu, Marko can >> repeat a stall on a dual Broadwell chipset on kernels: >> >> * 5.15.1 - https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.15.1 >> * 5.14.16 - https://packages.debian.org/sid/linux-image-5.14.0-4-amd64 >> >> Detailed observations: >> https://jira.mariadb.org/browse/MDEV-26674 >> >> The previous script has been adapted to use MariaDB-10.6 package and >> sysbench to demonstrate a workload, I've changed Marko's script to >> work with the distro packages and use innodb_use_native_aio=1. >> >> MariaDB packages: >> >> https://mariadb.org/download/?t=repo-config >> (needs a distro that has liburing userspace libraries as standard support) >> >> Script: >> >> https://jira.mariadb.org/secure/attachment/60358/Mariabench-MDEV-26674-io_uring-1 >> >> The state is achieved either when the sysbench prepare stalls, or the >> tps printed at 5 second intervals falls to 0. > > Thanks, this is most useful! I'll take a look at this. Would it be possible to turn this into a full reproducer script? Something that someone that knows nothing about mysqld/mariadb can just run and have it reproduce. If I install the 10.6 packages from above, then it doesn't seem to use io_uring or be linked against liburing. The script also seems to assume that various things are setup appropriately, like SRCTREE, MDIR, etc. -- Jens Axboe
