[ktap] Re: Regarding running ktap in linux less than 3.1

From: "zhangwei(Jovi)" <jovi.zhangwei@xxxxxxxxx>
To: Lalatendu Das <lalatdas@xxxxxxxxx>
Date: Fri, 4 Oct 2013 15:13:46 +0800

Hi Lalatendu,

On Thu, Oct 3, 2013 at 9:26 PM, Lalatendu Das <lalatdas@xxxxxxxxx> wrote:
> Hi,
> First off many congrats for the effort on tool like ktap.
> While trying my hand in running ktap on RHEL 6.4 the make command failed to
> build the module.
> It warns of using a kernel version lesser than 3.1.
>
> Where as I was using 2.6.32-358.2.1.el6 which is what published through RHEL
> 6.4.
>
> Can you please point me where can I  find a patch, applying which it will
> successfully build module in RHEL 6.4 ?
>
> In case you think I must do my home work can you atleast point me what all
> changes I must do.. I will do them myself.
>
Thanks for your interest on ktap. (Involved ktap@xxxxxxxxxxxxx)

Currently ktap cannot work for those kernel older than 3.1, the main technical
reason is perf callback mechanism is not fully supported before 3.1, and ktap
is mainly based on perf callback (see function perf_event_create_kernel_counter
in interpreter/library/kdebug.c)

But this is not means kernel older than 3.1 definitely cannot use
ktap, for kernel
near 3.0, perhaps just need some small kernel patch to extend perf callback,
but for those kernel much older than 3.0, I'm not sure that, this is much depend
on perf functionality porting wok, except this, probably some kdebug.c also need
some adaption work to work correct with 2.6.32.

Feel free to contact us if you have any question.

Thank you.

jovi

[ktap] Re: Regarding running ktap in linux less than 3.1

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