Re: [GIT PULL tip/x86/mm] xen/x86 fixes

[Yinghai Lu <yinghai@kernel.org>]

On 03/16/2011 07:43 AM, Stefano Stabellini wrote:
> actually attach the logs :)
>
> On Wed, 16 Mar 2011, Stefano Stabellini wrote:
>> On Fri, 11 Mar 2011, Konrad Rzeszutek Wilk wrote:
>>> On Fri, Mar 11, 2011 at 01:17:23PM +0000, Stefano Stabellini wrote:
>>>> Hello,
>>>> recently we had a couple of long discussions with Yinghai about boot
>>>> crashes on xen, related to pagetable initialization.
>>>> As a result we came up with three patches, two of them fix the first [1]
>>>> boot crash and provide a nice cleanup on native:
>>>
>>> I don't know why this is happening now, but it could be very well
>>> related to the build config. Smaller builds don't seem to encounter this, while
>>> this is a distro type build. If I use:
>>>
>>>> Stefano Stabellini (1):
>>>>        xen: set max_pfn_mapped to the last pfn mapped
>>>
>>> it hangs during bootup. The machine hangs during the box (no keyboard interaction)
>>> and I can see this in the bootup.
>>
>> Konrad sent me few other logs offline: log1 is the log of the hang and
>> log2 is a successful boot (reverting the problematic patch).
>> It looks like the SP5100 TCO WatchDog Timer Driver is using ioremap on
>> an address (0xb8fe00) that belongs to the memory range used for the
>> pagetable (0x9fc000-0xf43fff).

Mar 15 16:09:04 phenom kernel: [    0.000000] found SMP MP-table at [ffff8800000ff780] ff780

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x000ff780-0x000ff78f]   * MP-table mpf

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x000fd240-0x000fd423]   * MP-table mpc

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x01cfd000-0x01d1c0e4]              BRK

Mar 15 16:09:04 phenom kernel: [    0.000000] MEMBLOCK configuration:

Mar 15 16:09:04 phenom kernel: [    0.000000]  memory size = 0x23fe39000

Mar 15 16:09:04 phenom kernel: [    0.000000]  memory.cnt  = 0x3

Mar 15 16:09:04 phenom kernel: [    0.000000]  memory[0x0]      [0x00000000010000-0x0000000009afff], 0x8b000 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  memory[0x1]      [0x00000000100000-0x000000bffaffff], 0xbfeb0000 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  memory[0x2]      [0x00000100000000-0x0000027fefdfff], 0x17fefe000 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved.cnt  = 0x5

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved[0x0]    [0x000000000fd240-0x000000000fd423], 0x1e4 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved[0x1]    [0x000000000ff780-0x000000000ff78f], 0x10 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved[0x2]    [0x00000001000000-0x00000001d1c0e4], 0xd1c0e5 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved[0x3]    [0x00000001e33000-0x00000016a36fff], 0x14c04000 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000]  reserved[0x4]    [0x000001f0f7e000-0x0000027fefdfff], 0x8ef80000 bytes

Mar 15 16:09:04 phenom kernel: [    0.000000] Scanning 0 areas for low memory corruption

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x00099000-0x0009afff]       TRAMPOLINE

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x00095000-0x00098fff]      ACPI WAKEUP

Mar 15 16:09:04 phenom kernel: [    0.000000] init_memory_mapping: 0000000000000000-00000000bffb0000

Mar 15 16:09:04 phenom kernel: [    0.000000] DEBUG find_early_table_space: _text=1000000 _end=1e33000 pgtable_start=9fc000 pgtable_end=9fc000

Mar 15 16:09:04 phenom kernel: [    0.000000]     memblock_x86_reserve_range: [0x009fc000-0x00f43fff]          PGTABLE

e820 said that range is ram and usable. so it is right for memblock to use it.

why TCO watchdog try to use ioremap with RAM?  BIOS put wrong mmio in that BAR?

could do some sanitary check in that driver.

also another question is why memblock_find return so low value, it should return value just under 00000000bffb0000
We are putting page-table high to make usable more continuous, instead of put it just under 512M.

Thanks

Yinghai