Subject: Re: [PATCH v9 00/13] blk: honor isolcpus configuration

From: Ming Lei <[email-masked]>
Date: Tue, 31 Mar 2026 09:01:48 +0800

On Mon, Mar 30, 2026 at 06:10:34PM -0400, Aaron Tomlin wrote:
> Hi Jens, Keith, Christoph, Sagi, Michael,
> 
> I have decided to drive this series forward on behalf of Daniel Wagner, the
> original author. This iteration addresses the outstanding architectural and
> concurrency concerns raised during the previous review cycle, and the series
> has been rebased on v7.0-rc5-509-g545475aebc2a.
> 
> Building upon prior iterations, this series introduces critical
> architectural refinements to the mapping and affinity spreading algorithms
> to guarantee thread safety and resilience against concurrent CPU-hotplug
> operations. Previously, the block layer relied on a shared global static
> mask (i.e., blk_hk_online_mask), which proved vulnerable to race conditions
> during rapid hotplug events. This vulnerability was recently highlighted by
> the kernel test robot, which encountered a NULL pointer dereference during
> rcutorture (cpuhotplug) stress testing due to concurrent mask modification.

Can you share the bug report link?

IMO, it should be solved as a backportable patch first if possible.

Thanks,
Ming