Re: [PATCHSET wq/for-6.8] workqueue: Implement system-wide max_active for unbound workqueues

[Tejun Heo]

Hello,

On Fri, Jan 05, 2024 at 02:44:08AM +0000, Naohiro Aota wrote:
> Thank you for the series. I applied the patches on btrfs's development tree
> below, and ran the benchmark.
> 
> https://gitlab.com/kdave/btrfs-devel.git misc-next
> 
> - misc-next, numa=off (baseline)
>   WRITE: bw=1117MiB/s (1171MB/s), 1117MiB/s-1117MiB/s (1171MB/s-1171MB/s), io=332GiB (356GB), run=304322-304322msec
> - misc-next + wq patches, numa=off
>   WRITE: bw=1866MiB/s (1957MB/s), 1866MiB/s-1866MiB/s (1957MB/s-1957MB/s), io=684GiB (735GB), run=375472-375472msec
> 
> So, the patches surely improved the performance. However, as show below, it
> is still lower than reverting previous workqueue patches. The reverting is
> done by reverse applying output of "git diff 4cbfd3de737b
> kernel/workqueue.c kernel/workqueue_internal.h include/linux/workqueue*
> init/main.c"
> 
> - misc-next + wq reverted, numa=off
>   WRITE: bw=2472MiB/s (2592MB/s), 2472MiB/s-2472MiB/s (2592MB/s-2592MB/s), io=732GiB (786GB), run=303257-303257msec

Can you describe the test setup in detail? What kind of machine is it? What
do you mean by `numa=off`? Can you report tools/workqueue/wq_dump.py output?

Thanks.

-- 
tejun