Re: [PATCHv3 00/13] scripts/gdb: Linux awareness debug commands

[Jan Kiszka]

On 2016-03-14 18:18, Kieran Bingham wrote:
> On 14/03/16 15:09, Jan Kiszka wrote:
>> On 2016-03-14 15:40, Kieran Bingham wrote:
>>> On 13/03/16 16:35, Jan Kiszka wrote:
>>>> On 2016-03-03 12:40, Kieran Bingham wrote:
>>>>> Hi Jan,
>>>>>
>>>>> V3 of the patchset respun. Now finally adding the lx-interrupts command
>>>>> after I resolved my issues with the Radix Tree parsing.
>>>>>
>>>>> This command only provides the interrupts that are available generically,
>>>>> and it seems that the /proc/interrupts function calls into arch specific
>>>>> layers to add extra information about arch specific interrupts.
>>>>>
>>>>> I'm not sure what to do about this yet - The values returned appear to be
>>>>> accurate - but it's just a subset of the information returned by proc.
>>>>>
>>>>
>>>> I didn't test this (due to the breakage in patch 10): Can you give
>>>> examples of what is missing, e.g. on ARM or x86?
>>> On ARM this is :
>>>
>>> (gdb) lx-interrupts
>>>             CPU0       CPU1
>>>   18:     587828     150187
>>>   36:      66574          0
>>>   41:          8          0
>>>   42:        106          0
>>>   43:        100          0
>>> (gdb) c
>>>
>>>
>>> vs
>>>
>>> root@ArmACookieMonster:~# cat /proc/interrupts
>>>            CPU0       CPU1
>>>  18:     588057     150274     GIC-0  27 Edge      arch_timer
>>>  20:          0          0     GIC-0  34 Level     timer
>>>  36:      66599          0     GIC-0  47 Level     eth0
>>>  39:          0          0     GIC-0  41 Level     mmci-pl18x (cmd)
>>>  40:          0          0     GIC-0  42 Level     mmci-pl18x (pio)
>>>  41:          8          0     GIC-0  44 Level     kmi-pl050
>>>  42:        106          0     GIC-0  45 Level     kmi-pl050
>>>  43:        112          0     GIC-0  37 Level     uart-pl011
>>>  49:          0          0     GIC-0  36 Level     rtc-pl031
>>> IPI0:          0          1  CPU wakeup interrupts
>>> IPI1:          0          0  Timer broadcast interrupts
>>> IPI2:      15867     281362  Rescheduling interrupts
>>> IPI3:          0          6  Function call interrupts
>>> IPI4:          0          0  CPU stop interrupts
>>> IPI5:          0          0  IRQ work interrupts
>>> IPI6:          0          0  completion interrupts
>>> Err:          0
>>>
>>> So quite a substantial subset :(
>>
>> Indeed. Given this delta, I'm reluctant to include that command at this
>> point.
> 
> Ok, understandable...
> 
> I think the radix-tree lookup could be useful for people though.
> This is used across filesystems, and other places.
> 
> Perhaps I should wrap this up into a gdb.Function rather than drop it?
> 

Sounds good. Maybe also augment Documentation/gdb-kernel-debugging.txt
with a nice example for this (and for other non-obvious features).

Jan

-- 
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux