[PATCH] hwlat_detector: update stats code to record when "outer" interval exceeds threshold

[Clark Williams]

The hwlat_detector polls the system clock (either ktime_get() or trace_clock_local())
source looking for intervals between successive reads which exceed a specified threshold.
There are two intervals examined, the "inner" interval which is between t1 and t2,
and the "outer" interval which is between t2 and t1' (i.e. the "next" t1 value).

This patch updates the detector module to record if the outer interval is the maximum
interval encountered during a run.

Reported-by: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Signed-off-by: Clark Williams <williams@xxxxxxxxxx>
---
 drivers/misc/hwlat_detector.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
index d2676b867e41..5ca7aa9780e0 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -294,6 +294,8 @@ static int get_sample(void)
 		/* Keep a running maximum ever recorded hardware latency */
 		if (sample > data.max_sample)
 			data.max_sample = sample;
+		if (outer_sample > data.max_sample)
+			data.max_sample = outer_sample;
 	}
 
 out:
-- 
2.4.3

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