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

From: Kees Cook
Date: Tue Nov 15 2016 - 16:36:10 EST


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. ;)

> I will try these patches out today and thanks for refactoring the init
> prz stuff.

Sure thing! It should make the multi-pmsg change easier too.

-Kees

--
Kees Cook
Nexus Security