Re: [PATCH v2] ramoops: use pstore interface

[Marco Stornelli <marco.stornelli@gmail.com>]

Il 02/12/2011 03:40, Chen Gong ha scritto:
> 于 2011/12/1 18:31, Marco Stornelli 写道:
>> Il 29/11/2011 18:24, Kees Cook ha scritto:
>>> On Mon, Nov 28, 2011 at 8:50 PM, Chen Gong<gong.chen@linux.intel.com>
>>> wrote:
>>>> 于 2011/11/29 4:09, Kees Cook 写道:
>>>>>
>>>>> Instead of using /dev/mem directly, use the common pstore
>>>>> infrastructure
>>>>> to handle Oops gathering and extraction.
>>>>>
>>>>> Signed-off-by: Kees Cook<keescook@chromium.org>
>>>>> ---
>>>>> This depends on the pstore changes waiting for -next in:
>>>>>
>>>>> http://git.kernel.org/?p=linux/kernel/git/aegl/linux.git;a=shortlog;h=refs/heads/next
>>>>>
>>>>>
>>>>> ---
>>>>> Documentation/ramoops.txt | 8 +-
>>>>> drivers/char/Kconfig | 1 +
>>>>> drivers/char/ramoops.c | 206
>>>>> ++++++++++++++++++++++++++++++++++-----------
>>>>> 3 files changed, 160 insertions(+), 55 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt
>>>>> index 8fb1ba7..a0b9d8e 100644
>>>>> --- a/Documentation/ramoops.txt
>>>>> +++ b/Documentation/ramoops.txt
>>>>> @@ -3,7 +3,7 @@ Ramoops oops/panic logger
>>>>>
>>>>> Sergiu Iordache<sergiu@chromium.org>
>>>>>
>>>>> -Updated: 8 August 2011
>>>>> +Updated: 17 November 2011
>>>>>
>>>>> 0. Introduction
>>>>>
>>>>> @@ -71,6 +71,6 @@ timestamp and a new line. The dump then continues
>>>>> with
>>>>> the actual data.
>>>>>
>>>>> 4. Reading the data
>>>>>
>>>>> -The dump data can be read from memory (through /dev/mem or other
>>>>> means).
>>>>> -Getting the module parameters, which are needed in order to parse the
>>>>> data, can
>>>>> -be done through /sys/module/ramoops/parameters/* .
>>>>> +The dump data can be read from the pstore filesystem. The format for
>>>>> these
>>>>> +files is "dmesg-ramoops-N", where N is the record number in
>>>>> memory. To
>>>>> delete
>>>>> +a stored record from RAM, simply unlink the respective pstore file.
>>>>
>>>> I think the definition of "mem_address" in the doc is not very
>>>> clear. It is
>>>> not a normal memory instead of a persistent RAM. I suggest adding more
>>>> descriptions.
>>>> It's better if there is a real example.
>>>
>>> Okay. I'm not sure it's in the scope of this patch, but I can try.
>>>
>>> Marco, do you have suggestions for how this could be enhanced?
>>>
>>
>> I don't know actually. It's not mandatory use a persistent memory. A
>> simple
>> piece of reserved RAM is ok. Obviously it will work only over reboot
>> and not
>> over power down. I define mem_address as a generic piece of reserved
>> memory.
>>
>> Marco
>
> Anyway, we need a pratical exmaple to instruct us how to use this diver.
>
>

For example we can use the mem parameter to reserve memory and use it as 
ramoops buffer, very simple.