Messages in this thread | | | Date | Thu, 5 May 2022 19:20:24 -0400 | Subject | Re: Issue With real-time patches on 5.15.y | From | Joseph Salisbury <> |
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On 5/5/22 19:18, Joseph Salisbury wrote: > Hello, > > I ran into a build failure after applying the rt40 real-time > patches[0] to an Ubuntu 22.04 kernel. The Ubuntu kernel is based on > upstream stable 5.15.y(5.15.34 currently). I believe this patch is > the specific one that introduces the build issue: > 0086-locking-Allow-to-include-asm-spinlock_types.h-from-l.patch. > > After a bisect, the following commit was identified as the cause for > the build failure: > b50854eca0e0 ("x86/pkru: Remove useless include") > > This commit was added to mainline as of 5.16-rc1 and not Cc'd to > stable, so it should not exist in 5.15.y. However, it was purposely > added to the Ubuntu kernel to enable x86 AMX support[1]. > > The real-time kernel build failure can be resolved by reverting commit > b50854eca0e0. The failure seems to be due to the removal of an > include of xstate.h from pkru.h and caused spinlock_t to not be > defined. The commit would only be reverted for the real-time kernel > and not any other kernels. I wanted to see if reverting the commit is > the proper approach, or if cherry-picking additional commits might be > a better solution in preparation for additional changes that might be > coming in the future? > > Any suggestions would be greatly appreciated. > > Thanks, > > Joe > > > [0] > https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.15/older/patches-5.15.34-rt40.tar.gz > [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1967750 Also, the following is the build failure that happens: arch/x86/include/asm/pgtable.h:55:8: error: unknown type name 'spinlock_t' 55 | extern spinlock_t pgd_lock; | ^~~~~~~~~~
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