Re: [patch 3/4] This patch introduces a new oprofile sample addfunction (oprofile_add_ext_hw_sample)

From: Robert Richter
Date: Tue Jan 04 2011 - 10:34:24 EST


On 20.12.10 08:05:44, graalfs@xxxxxxxxxxxxxxxxxx wrote:
> From: graalfs@xxxxxxxxxxxxxxxxxx
>
> This patch introduces a new oprofile sample add function (oprofile_add_ext_hw_sample)
> that can also take task_struct as an argument, which is used by the hwsampler kernel module
> when copying hardware samples to OProfile buffers.
>
> Signed-off-by: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Maran Pakkirisamy <maranp@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Heinz Graalfs <graalfs@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/oprofile/cpu_buffer.c | 26 +++++++++++++++++++-------
> 1 file changed, 19 insertions(+), 7 deletions(-)

> +void oprofile_add_ext_hw_sample(unsigned long pc, struct pt_regs * const regs,
> + unsigned long event, int is_kernel,
> + struct task_struct *task)
> +{
> + __oprofile_add_ext_sample(pc, regs, event, is_kernel, task);
> +}
> +EXPORT_SYMBOL_GPL(oprofile_add_ext_hw_sample);

Hmm, I am not convinced of this new interface between the hwsampler
module and oprofile. It is asymmetric and bloats the function's
parameters list. A first simplification would be to not implement
hwsampler as module and integrate this in oprofile. Then, we can look
for a better way to add samples to the oprofile buffer. What do you
think?

-Robert

--
Advanced Micro Devices, Inc.
Operating System Research Center

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