Re: [mainline][BUG] Observed Workqueue lockups on offline CPUs.

[Shrikanth Hegde <sshegde@linux.ibm.com>]

Hi Samir.

On 4/29/26 3:46 PM, Samir M wrote:
> 
> Hi Boqun,
> 
> Thank you for pointing me to the existing patches. I have tested both 
> Paul's patch [1] and TJ's workqueue patch [2] on my PowerPC system (80 
> CPUs), and can confirm that the workqueue lockup issue is not observed.
> 

Can you try only paul's patch and confirm if the issue is fixed?

> Test Environment:
> - System: PowerPC with 80 CPUs ( e.g. PowerPC LPARs with 80 online and 
> 384 possible CPUs)
> - Kernel version: Latest upstream (7.1-rc1)
> 
> Regression Testing Results:
> All tests completed successfully with no issues observed:
> - Hackbench
> - Kernel selftests
> - LTP scheduler tests
> 
> The workqueue lockup that was previously occurring is no longer present 
> with the patches applied.
> 
> References:
> [1]: https://lore.kernel.org/rcu/ed1fa6cd-7343-4ca3-8b9d- 
> d699ca496f83@paulmck-laptop/
> [2]: https://lore.kernel.org/rcu/adlHKowvhn8AGXCc@slm.duckdns.org/
> 
> Best regards,
> Samir