• Carl Love's avatar
    powerpc/oprofile: Fix mutex locking for cell spu-oprofile · a5598ca0
    Carl Love authored
    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: default avatarCarl Love <carll@us.ibm.com>
    Signed-off-by: default avatarMaynard Johnson <maynardj@us.ibm.com>
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    Acked-by: default avatarAcked-by: Robert Richter <robert.richter@amd.com>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    a5598ca0
buffer_sync.c 15 KB