Re: uring regression - lost write request

[Jens Axboe <axboe@kernel.dk>]

On 11/9/21 3:58 PM, Daniel Black wrote:
>> On Sat, Oct 30, 2021 at 6:30 PM Salvatore Bonaccorso <carnil@debian.org> 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.

-- 
Jens Axboe