as a part of a research project I am porting the Linux kernel of the Xeon Phi from version 18.104.22.168 to 3.2.14.
I can successfully boot the kernel (i.e. I can see "<6>[ 45.740227] Freeing unused kernel memory: 548k freed" in the dmesg buffer) and init has been called (anything that I had before switch_root gets printed on the dmesg buffer).
Now I am stucked because during the porting I possibly miss something. The error happen during either switch_root or while cpio-ing on tmpfs. I modified the kernel in order to enable send_IPI_all(NMI_VECTOR) in arch/x86/kernel/apic/hw_nmi.c:arch_trigger_all_cpu_backtrace(..). So, that I can have a kernel stack dump on the locked core. In your kernel NMIs, i.e. irq vector 0x2, are sent through arch/x86/kernel/apic/apic_phys_fla64.c:default_send_IPI_mask_sequence_phys(..). I did different experiments and no NMIs are received after calling default_send_IPI_mask_sequence_phys(..). I didn't do the exact same experiment on 22.214.171.124 but I did see that NMI are always zero (in /proc/interrupts).
1. Do I miss something about NMIs? Is the code on 126.96.36.199 completely updated to support NMIs?
2. Is there anyone else working on the porting of the Linux kernel for the Xeon Phi to another kernel version?