diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/hwlat_detector.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c index 6864f3c..c07e859 100644 --- a/drivers/misc/hwlat_detector.c +++ b/drivers/misc/hwlat_detector.c @@ -143,6 +143,7 @@ static void detector_exit(void); struct sample { u64 seqnum; /* unique sequence */ u64 duration; /* ktime delta */ + u64 outer_duration; /* ktime delta (outer loop) */ struct timespec timestamp; /* wall time */ unsigned long lost; }; @@ -219,11 +220,13 @@ static struct sample *buffer_get_sample(struct sample *sample) */ static int get_sample(void *unused) { - ktime_t start, t1, t2; + ktime_t start, t1, t2, last_t2; s64 diff, total = 0; u64 sample = 0; + u64 outer_sample = 0; int ret = 1; + last_t2.tv64 = 0; start = ktime_get(); /* start timestamp */ do { @@ -231,7 +234,22 @@ static int get_sample(void *unused) t1 = ktime_get(); /* we'll look for a discontinuity */ t2 = ktime_get(); + if (last_t2.tv64) { + /* Check the delta from outer loop (t2 to next t1) */ + diff = ktime_to_us(ktime_sub(t1, last_t2)); + /* This shouldn't happen */ + if (diff < 0) { + pr_err(BANNER "time running backwards\n"); + goto out; + } + if (diff > outer_sample) + outer_sample = diff; + } + last_t2 = t2; + total = ktime_to_us(ktime_sub(t2, start)); /* sample width */ + + /* This checks the inner loop (t1 to t2) */ diff = ktime_to_us(ktime_sub(t2, t1)); /* current diff */ /* This shouldn't happen */ @@ -246,12 +264,13 @@ static int get_sample(void *unused) } while (total <= data.sample_width); /* If we exceed the threshold value, we have found a hardware latency */ - if (sample > data.threshold) { + if (sample > data.threshold || outer_sample > data.threshold) { struct sample s; data.count++; s.seqnum = data.count; s.duration = sample; + s.outer_duration = outer_sample; s.timestamp = CURRENT_TIME; __buffer_add_sample(&s); @@ -738,10 +757,11 @@ static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf, } } - len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\n", - sample->timestamp.tv_sec, - sample->timestamp.tv_nsec, - sample->duration); + len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\t%llu\n", + sample->timestamp.tv_sec, + sample->timestamp.tv_nsec, + sample->duration, + sample->outer_duration); /* handling partial reads is more trouble than it's worth */ |