From ff71d395f3cd5e5efe4b9b3c94c2d41581fb9d8c Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 3 Aug 2015 12:57:19 -0500 Subject: [PATCH] greybus: loopback: compute average stats on demand only Stop recording and updating the average every time a sample is recorded. Instead, compute it from the sum and count only when it's required. Signed-off-by: Alex Elder Reviewed-by: Bryan O'Donoghue Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/loopback.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 432eeabe963b..e76f8a70d113 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -25,7 +25,6 @@ struct gb_loopback_stats { u32 min; u32 max; - u64 avg; u64 sum; u32 count; }; @@ -107,7 +106,11 @@ static ssize_t name##_avg_show(struct device *dev, \ { \ struct gb_connection *connection = to_gb_connection(dev); \ struct gb_loopback *gb = connection->private; \ - return sprintf(buf, "%llu\n", gb->name.avg); \ + struct gb_loopback_stats *stats = &gb->name; \ + u32 count = stats->count ? stats->count : 1; \ + u64 avg = stats->sum + count / 2; /* round closest */ \ + u32 rem = do_div(avg, count); \ + return sprintf(buf, "%llu.%06u\n", avg, 1000000 * rem / count); \ } \ static DEVICE_ATTR_RO(name##_avg) @@ -367,8 +370,6 @@ static void gb_loopback_update_stats(struct gb_loopback_stats *stats, u32 val) stats->max = val; stats->sum += val; stats->count++; - stats->avg = stats->sum; - do_div(stats->avg, stats->count); } static void gb_loopback_requests_update(struct gb_loopback *gb, u32 latency) -- 2.20.1