ring-buffer: replace constants with time macros in ring-buffer-benchmark
Steven Rostedt [Fri, 8 May 2009 14:56:33 +0000 (10:56 -0400)]
The use of numeric constants is discouraged. It is cleaner and more
descriptive to use macros for constant time conversions.

This patch also removes an extra new line.

[ Impact: more descriptive time conversions ]

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/ring_buffer_benchmark.c

index a21aa7b..7d3aef9 100644 (file)
@@ -253,7 +253,7 @@ static void ring_buffer_producer(void)
        }
 
        time = end_tv.tv_sec - start_tv.tv_sec;
-       time *= 1000000;
+       time *= USEC_PER_SEC;
        time += (long long)((long)end_tv.tv_usec - (long)start_tv.tv_usec);
 
        entries = ring_buffer_entries(buffer);
@@ -273,7 +273,8 @@ static void ring_buffer_producer(void)
        pr_info("Missed:   %ld\n", missed);
        pr_info("Hit:      %ld\n", hit);
 
-       do_div(time, 1000);
+       /* Convert time from usecs to millisecs */
+       do_div(time, USEC_PER_MSEC);
        if (time)
                hit /= (long)time;
        else
@@ -282,18 +283,19 @@ static void ring_buffer_producer(void)
        pr_info("Entries per millisec: %ld\n", hit);
 
        if (hit) {
-               avg = 1000000 / hit;
+               /* Calculate the average time in nanosecs */
+               avg = NSEC_PER_MSEC / hit;
                pr_info("%ld ns per entry\n", avg);
        }
 
-
        if (missed) {
                if (time)
                        missed /= (long)time;
 
                pr_info("Total iterations per millisec: %ld\n", hit + missed);
 
-               avg = 1000000 / (hit + missed);
+               /* Caculate the average time in nanosecs */
+               avg = NSEC_PER_MSEC / (hit + missed);
                pr_info("%ld ns per entry\n", avg);
        }
 }