Add log_avg_msec option

By default, fio will note an entry in the bw/iops/lat logs for every
IO that is completed. This quickly eats up a lot of disk space
for long running jobs. By setting this option to eg 1000, fio will
average the results logged over 1 second instead. This reduces the
resolution of the log, but makes it more manageable.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/options.c b/options.c
index 2e1e709..f9bd1a4 100644
--- a/options.c
+++ b/options.c
@@ -1951,6 +1951,13 @@
 		.help	= "Write log of IOPS during run",
 	},
 	{
+		.name	= "log_avg_msec",
+		.type	= FIO_OPT_INT,
+		.off1	= td_var_offset(log_avg_msec),
+		.help	= "Average bw/iops/lat logs over this period of time",
+		.def	= "0",
+	},
+	{
 		.name	= "hugepage-size",
 		.type	= FIO_OPT_INT,
 		.off1	= td_var_offset(hugepage_size),