diff options
| author | Daniel Lezcano <daniel.lezcano@linaro.org> | 2019-05-27 23:55:16 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-06-12 11:47:03 +0300 |
| commit | 3c2e79f4cef7938125b356e7f5c8fd038212619a (patch) | |
| tree | cfd53f33ed21b4e585e7c222dbb6f7a71043c8e1 /kernel/irq/timings.c | |
| parent | 2840eef0513c518faeb8a0ab8d07268c6285cdd0 (diff) | |
| download | linux-3c2e79f4cef7938125b356e7f5c8fd038212619a.tar.xz | |
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/irq/timings.c')
| -rw-r--r-- | kernel/irq/timings.c | 2 |
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 */ |