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I get a kernel crash at BUG() here - http://lxr.free-electrons.com/source/mm/bootmem.c?v=3.10#L385 with the following message

2kernel BUG at /kernel/mm/bootmem.c:385!

What could be a possible reason for this?

Following is the function call trace

[<c0e165f8>] (mark_bootmem+0xd0/0xe0) from [<c0e05d64>] (bootmem_init+0x16c/0x26
[<c0e05d64>] (bootmem_init+0x16c/0x264) from [<c0e07980>] (paging_init+0x734/0x7
[<c0e07980>] (paging_init+0x734/0x7d4) from [<c0e03f20>] (setup_arch+0x3e8/0x69c
[<c0e03f20>] (setup_arch+0x3e8/0x69c) from [<c0e007d8>] (start_kernel+0x78/0x370
[<c0e007d8>] (start_kernel+0x78/0x370) from [<10008074>] (0x10008074)

Thanks

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The mm/bootmem.c file is responsible for Boot Memory Allocator. Function mark_bootmem marks memory pages between start and end addresses (start is rounded down and end is rounded up to page boundaries) as reserved (or not reserved when used for freeing) for this allocator.

It iterates over bdata_list trying to find a region containing first page from requested address range. It it won't find it, the BUG() you mentioned will be triggered. The same BUG() will be triggered if it succeeds finding it, but the region is not large enough (end is outside of the region). So this BUG() means that it wasn't able to find requested memory region to mark.

Now if I understand the kernel code correctly, on normal UMA systems there will be only one entry in bdata_list and it should describe the range of lowmemory pages available in the system. Since you didn't provide too much information about your system it's hard to guess exact reason for the problem but in general, it seems that your memory setup is broken. This thing is very architecture specific so it's hard to tell what exactly is going on.

于 2014-04-05T20:29:01.017 回答