• Jin Yao's avatar
    perf report: Calculate the average cycles of iterations · c4ee0625
    Jin Yao authored
    The branch history code has a loop detection function. With this, we can
    get the number of iterations by calculating the removed loops.
    
    While it would be nice for knowing the average cycles of iterations.
    This patch adds up the cycles in branch entries of removed loops and
    save the result to the next branch entry (e.g. branch entry A).
    
    Finally it will display the iteration number and average cycles at the
    "from" of branch entry A.
    
    For example:
    perf record -g -j any,save_type ./div
    perf report --branch-history --no-children --stdio
    
    --22.63%--main div.c:42 (RET CROSS_2M)
              compute_flag div.c:28 (cycles:2 iter:173115 avg_cycles:2)
              |
               --10.73%--compute_flag div.c:27 (RET CROSS_2M)
                         rand rand.c:28 (cycles:1)
                         rand rand.c:28 (RET CROSS_2M)
                         __random random.c:298 (cycles:1)
                         __random random.c:297 (COND_BWD CROSS_2M)
                         __random random.c:295 (cycles:1)
                         __random random.c:295 (COND_BWD CROSS_2M)
                         __random random.c:295 (cycles:1)
                         __random random.c:295 (RET CROSS_2M)
    Signed-off-by: default avatarYao Jin <yao.jin@linux.intel.com>
    Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Kan Liang <kan.liang@intel.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/1502111115-18305-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    c4ee0625
callchain.h 7.92 KB