Re: [PATCH] blk-cgroup: add spin_lock for u64_stats_update

[Tejun Heo]

Hello,

On Fri, Jul 05, 2024 at 03:55:44PM +0800, boy.wu wrote:
> From: Boy Wu <boy.wu@xxxxxxxxxxxx>
> 
> In 32bit SMP systems, if the system is stressed on the sys node
> by processes, it may cause blkcg_fill_root_iostats to have a concurrent

What is sys node?

> problem on the seqlock in u64_stats_update, which will cause a deadlock 
> on u64_stats_fetch_begin in blkcg_print_one_stat.

I'm not following the scenario. Can you please detail the scenario where
this leads to deadlocks?

Thanks.

-- 
tejun