hi, Guenter
http://www.gossamer-threads.com/lists/linux/kernel/2011061
>[PATCH] Revert "percpu: free percpu allocation info for uniprocessor system"
>
> The commit causes a hang with a crisv32 image. This may be an architecture
> problem, but at least for now the revert is necessary to be able to boot a
> crisv32 image.
Yes, it is a crisv32 specific issue. The crisv32 was paniced on the BUG() macro
in function mark_bootmem. The call path is :
pcpu_free_alloc_info
-> memblock_free_early
-> free_bootmem
-> mark_bootmem
-> BUG()
The root source is that arch/cris/kernel/setup.c:setup_arch compute start_pfn
and max_pfn from *virtual* address.
|---------- arch/cris/kernel/setup.c:setup_arch -----------------------
| start_pfn = PFN_UP(memory_start); /* usually c0000000 + kernel + romfs */
| max_pfn = PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
|---------- arch/cris/kernel/setup.c:setup_arch -----------------------
So, when memblock_free_early pass the *physical* address of ai to mark_bootmem.
The first if statement of mark_bootmem become ture. And then hit the BUG() macro.
After applied the attached patch, pcpu_free_alloc_info works as expect. It had
been test with your toolchain and patches you provided to me.
http://server.roeck-us.net/qemu/crisv32/
cc'ed Mikael and Jesper, as they are Axis staff.
thanks