Re: [patch v2 2/3] This patch enhances OProfile to support System zs hardware sampling feature

[Robert Richter <robert.richter@amd.com>]

On 21.01.11 05:06:53, Heinz Graalfs wrote:
> From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
> 
> OProfile is enhanced to export all files for controlling System z's hardware sampling,
> and to invoke hwsampler exported functions to initialize and use System z's hardware sampling.
> 
> The patch invokes hwsampler_setup() during oprofile init and exports following
> hwsampler files under oprofilefs if hwsampler's setup succeeded:
> 
> A new directory for hardware sampling based files
> 
>  /dev/oprofile/hwsampling/
> 
> The userland daemon must explicitly write to the following files
> to disable (or enable) hardware based sampling
> 
>  /dev/oprofile/hwsampling/hwsampler
> 
> to modify the actual sampling rate
> 
>  /dev/oprofile/hwsampling/hw_interval
> 
> to modify the amount of sampling memory (measured in 4K pages)
> 
>  /dev/oprofile/hwsampling/hw_sdbt_blocks
> 
> The following files are read only and show
> the possible minimum sampling rate
> 
>  /dev/oprofile/hwsampling/hw_min_interval
> 
> the possible maximum sampling rate
> 
>  /dev/oprofile/hwsampling/hw_max_interval
> 
> The patch splits the oprofile_timer_[init/exit] function so that it can be also called
> through user context (oprofilefs) to avoid kernel oops.
> 
> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Signed-off-by: Maran Pakkirisamy <maranp@linux.vnet.ibm.com>
> Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
> ---
>  arch/s390/oprofile/Makefile          |    3 
>  arch/s390/oprofile/hwsampler_files.c |  146 +++++++++++++++++++++++++++++++++++
>  arch/s390/oprofile/init.c            |    7 +
>  drivers/oprofile/oprof.c             |   32 +++++++
>  drivers/oprofile/oprof.h             |    2 
>  drivers/oprofile/timer_int.c         |   16 +++
>  include/linux/oprofile.h             |   21 +++++
>  7 files changed, 222 insertions(+), 5 deletions(-)

Applied with following changes:
    * whitespace changes in Makefile and timer_int.c

I reworked some changes in a follow-on patch which I apply on top of
your patch set.

-Robert

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Advanced Micro Devices, Inc.
Operating System Research Center