On Wed Feb 4, 2026 at 11:12 AM GMT, Peter Zijlstra wrote:

On Tue, Feb 03, 2026 at 01:15:21PM +0100, Peter Zijlstra wrote:

quoted

But I'm really somewhat sad that 64bit can't do better than this.

Here, the below builds and boots (albeit with warnings because printf
format crap sucks).

Hi Peter,

I am not sure if it's worth the complexity to do this for the NMI code path.
I don't think NMI code path is hot enough that this is necessary?

Best,
Gary

---
 arch/x86/Kconfig               |  1 +
 arch/x86/include/asm/preempt.h | 53 ++++++++++++++++++++++++++++++------------
 arch/x86/kernel/cpu/common.c   |  2 +-
 include/linux/hardirq.h        |  7 +++---
 include/linux/preempt.h        | 52 ++++++++++++++++++++++++++++++++++-------
 init/main.c                    |  2 +-
 kernel/Kconfig.preempt         |  4 ++++
 kernel/sched/core.c            |  8 +++----
 kernel/softirq.c               | 10 +++++++-
 kernel/time/timer.c            |  2 +-
 lib/locking-selftest.c         |  2 +-
 11 files changed, 106 insertions(+), 37 deletions(-)