Re: [PATCH v3 0/8] pstore: Improve performance of ftrace backend with ramoops

[Joel Fernandes]

Hi Kees,

On Tue, Nov 15, 2016 at 1:36 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> On Tue, Nov 15, 2016 at 11:55 AM, Joel Fernandes <joelaf@xxxxxxxxxx> wrote:
>> Hi Kees,
>>
>> On Fri, Nov 11, 2016 at 2:21 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>>> Hi Joel,
>>>
>>> I've reorganized a bunch of the logic here. Since pstore is going to need
>>> the init_przs() logic for multiple pmsg przs, I wanted to get this in and
>>> make sure I was happy with how it looks. I figured this would reduce our
>>> round-trip time on reviews. :)
>>>
>>> Can you test this series and verify that it works as you're expecting? I've
>>> validated some basic behavior already, but don't have a good test-case for
>>> ftrace. What commands do you actually use for testing ftrace? I'd like to
>>> add something to my local tests.
>>
>> I normally do the following:
>>
>> dd if=/dev/urandom | pv | dd of=/dev/null
>>
>> and in parallel, I do a:
>> echo 1 > /sys/kernel/debug/pstore/record_ftrace
>>
>> and then check the throughput; and then reboot the system and do a
>> read out of /sys/fs/pstore/ ftrace file.
>
> Cool. Does something normally parse these? Lots of kernel addresses is
> all I see. ;)
>

It should print symbol names if KALLSYMS is working properly as it
uses %pf (in pstore_ftrace_seq_show function).

Thanks,

Joel