aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorDaniel Lezcano <daniel.lezcano@linaro.org>2019-05-27 22:55:16 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-06-12 10:47:03 +0200
commit3c2e79f4cef7938125b356e7f5c8fd038212619a (patch)
treecfd53f33ed21b4e585e7c222dbb6f7a71043c8e1 /kernel
parent2840eef0513c518faeb8a0ab8d07268c6285cdd0 (diff)
downloadtip-3c2e79f4cef7938125b356e7f5c8fd038212619a.tar.gz
tip-3c2e79f4cef7938125b356e7f5c8fd038212619a.tar.xz
tip-3c2e79f4cef7938125b356e7f5c8fd038212619a.zip
genirq/timings: Optimize the period detection speed
With a minimal period and if there is a period which is a multiple of it but lesser than the max period then it will be detected before and the minimal period will be never reached. 1 2 1 2 1 2 1 2 1 2 1 2 <-----> <-----> <-----> <-> <-> <-> <-> <-> <-> In that case, the minimum period is 2 and the maximum period is 5. That means all repeating pattern of 2 will be detected as repeating pattern of 4, it is pointless to go up to 2 when searching for the period as it will always fail. Remove one loop iteration by increasing the minimal period to 3. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20190527205521.12091-4-daniel.lezcano@linaro.org
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/timings.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c
index 19d2fad379ee..1d1c411d4cae 100644
--- a/kernel/irq/timings.c
+++ b/kernel/irq/timings.c
@@ -261,7 +261,7 @@ void irq_timings_disable(void)
#define EMA_ALPHA_VAL 64
#define EMA_ALPHA_SHIFT 7
-#define PREDICTION_PERIOD_MIN 2
+#define PREDICTION_PERIOD_MIN 3
#define PREDICTION_PERIOD_MAX 5
#define PREDICTION_FACTOR 4
#define PREDICTION_MAX 10 /* 2 ^ PREDICTION_MAX useconds */