Hello, booting the current kernel (6.9.0-rc1, master/712e1425) on x86_64 with nohz_full=0 cause a page fault and prevents the kernel from booting. Steps to reproduce: - make defconfig - set CONFIG_NO_HZ_FULL=y - set CONFIG_SUSPEND=n and CONFIG_HIBERNATION=n (to get CONFIG_PM_SLEEP_SMP=n) - make - qemu-system-x86_64 -nographic -cpu qemu64 -smp cores=2 -m 1024 -kernel arch/x86/boot/bzImage -append "earlyprintk=ttyS0 console=ttyS0 root=/dev/dummy rootwait nohz_full=0" I have attached the output of a failed nohz_full=0 boot as nohz_full_0.txt and - for reference - the output of a nohz_full=1 boot as nohz_full_1.txt. Interestingly enough, using the deprecated isolcpus parameter to enable NO_HZ for cpu0 works. I've attached the output as isolcpus_nohz_0.txt. Bisecting showed 5797b1c18919cd9c289ded7954383e499f729ce0 as first bad commit.
Created attachment 306068 [details] Output when booting with nohz_full=0
Created attachment 306069 [details] Output when booting with nohz_full=1
Created attachment 306070 [details] Output when booting with isolcpus=nohz,0
Forwarded by mail: https://lore.kernel.org/all/5be248c6-cdda-4d2e-8fae-30fc2cc124c0@leemhuis.info/
This looks like another report about the problem: https://lore.kernel.org/all/20240402105847.GA24832@redhat.com/ #regzbot monitor https://lore.kernel.org/all/20240402105847.GA24832@redhat.com/
Bug was fixed in commit 5097cbcb [1] which is included in kernel >= 6.9-rc6. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5097cbcb38e6e0d2627c9dde1985e91d2c9f880e