On Tue, Mar 31, 2026 at 09:01:48AM +0800, Ming Lei wrote: > Can you share the bug report link? > > IMO, it should be solved as a backportable patch first if possible.
Hi Ming, Thanks for taking a look at the series. Here is the link to the kernel test robot's bug report: https://lore.kernel.org/oe-lkp/[email protected] Regarding a backportable patch, the NULL pointer dereference is actually not an existing mainline bug. It was a regression introduced specifically by the previous iteration of this series, specifically by Patch 10: "blk-mq: use hk cpus only when isolcpus=io_queue is enabled". The previously implementation introduced the global static blk_hk_online_mask variable, which caused the race condition during the robot's cpuhotplug stress tests. Because that flawed logic was confined to the unmerged v8 patches and never made it into a mainline release, there is nothing to backport to stable trees. Version 9 simply drops that global mask approach entirely in favour of local data_race(cpu_online_mask) snapshots, fixing the architectural flaw within the series itself. Kind regards, -- Aaron Tomlin
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