Re: powerpc/cell/oprofile: fix mutex locking for spu-oprofile

Robert Richter
2008-08-20T12:40:31Z

On 11.08.08 09:25:07, Arnd Bergmann wrote:
> From: Carl Love <cel@us.ibm.com>
>
> The issue is the SPU code is not holding the kernel mutex lock while
> adding samples to the kernel buffer.
>
> This patch creates per SPU buffers to hold the data. Data
> is added to the buffers from in interrupt context. The data
> is periodically pushed to the kernel buffer via a new Oprofile
> function oprofile_put_buff(). The oprofile_put_buff() function
> is called via a work queue enabling the funtion to acquire the
> mutex lock.
>
> The existing user controls for adjusting the per CPU buffer
> size is used to control the size of the per SPU buffers.
> Similarly, overflows of the SPU buffers are reported by
> incrementing the per CPU buffer stats. This eliminates the
> need to have architecture specific controls for the per SPU
> buffers which is not acceptable to the OProfile user tool
> maintainer.
>
> The export of the oprofile add_event_entry() is removed as it
> is no longer needed given this patch.
>
> Note, this patch has not addressed the issue of indexing arrays
> by the spu number. This still needs to be fixed as the spu
> numbering is not guarenteed to be 0 to max_num_spus-1.
>
> Signed-off-by: Carl Love <carll@us.ibm.com>
> Signed-off-by: Maynard Johnson <maynardj@us.ibm.com>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Robert Richter <robert.richter@amd.com>

-Robert

--
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com