Hi Stephen, Mike, Ingo,

Starting from

>>>>

[dmitri.vorobiev@amber linux-2.6]$ git bisect good
66c38e394e8c178c806266bb213f1087cd182701 is first bad commit
commit 66c38e394e8c178c806266bb213f1087cd182701
Author: Mike Travis <travis@sgi.com>
Date:   Mon Apr 28 14:09:07 2008 -0700

    x86: remove static boot_cpu_pda array v2

      * Remove the boot_cpu_pda array and pointer table from the data section.
        Allocate the pointer table and array during init.  do_boot_cpu()
        will reallocate the pda in node local memory and if the cpu is being
        brought up before the bootmem array is released (after_bootmem = 0),
        then it will free the initial pda.  This will happen for all cpus
        present at system startup.

        This removes 512k + 32k bytes from the data section.

    For inclusion into sched-devel/latest tree.

    Based on:
        git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
        +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

    Signed-off-by: Mike Travis <travis@sgi.com>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>

<<<<

the x86_64 kernel stopped booting for me. The symptom is that no output
whatsoever is produced after the following command:

>>>>

qemu-0.9.1/bin/qemu-system-x86_64 image_64.raw \
        -kernel src/linux-2.6/arch/x86/boot/bzImage \
        -append "console=ttyS0 root=/dev/hda1 ro" -nographic \
        -redir tcp:2222::22 -m 512

<<<<

Qemu just hangs seemingly doing nothing. Normally, the usual boot log is
displayed.

Bisection on linux-next leads to the commit given above. Config attached.

Thanks,
Dmitri