• Thomas Richter's avatar
    s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace · fe5908bc
    Thomas Richter authored
    Introduce a PMU device named cpum_cf_diag. It extracts the
    values of all counters in all authorized counter sets and stores
    them as event raw data. This is done with the STORE CPU COUNTER
    MULTIPLE instruction to speed up access. All counter sets
    fit into one buffer. The values of each counter are taken
    when the event is started on the performance sub-system and when
    the event is stopped.
    This results in counter values available at the start and
    at the end of the measurement time frame. The difference is
    calculated for each counter. The differences of all
    counters are then saved as event raw data in the perf.data
    file.
    
    The counter values are accompanied by the time stamps
    when the counter set was started and when the counter set
    was stopped. This data is part of a trailer entry which
    describes the time frame, counter set version numbers,
    CPU speed, and machine type for later analysis.
    Signed-off-by: default avatarThomas Richter <tmricht@linux.ibm.com>
    Reviewed-by: default avatarHendrik Brueckner <brueckner@linux.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    fe5908bc
Makefile 2.77 KB