• Paul Mackerras's avatar
    powerpc/pseries: Re-enable dispatch trace log userspace interface · 872e439a
    Paul Mackerras authored
    Since the cpu accounting code uses the hypervisor dispatch trace log
    now when CONFIG_VIRT_CPU_ACCOUNTING = y, the previous commit disabled
    access to it via files in the /sys/kernel/debug/powerpc/dtl/ directory
    in that case.  This restores those files.
    To do this, we now have a hook that the cpu accounting code will call
    as it processes each entry from the hypervisor dispatch trace log.
    The code in dtl.c now uses that to fill up its ring buffer, rather
    than having the hypervisor fill the ring buffer directly.
    This also fixes dtl_file_read() to handle overflow conditions a bit
    better and adds a spinlock to ensure that race conditions (multiple
    processes opening or reading the file concurrently) are handled
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
lppaca.h 8.57 KB