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author | Mark Whitehorn <kd0aij@gmail.com> | 2014-12-20 10:27:02 -0700 |
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committer | Mark Whitehorn <kd0aij@gmail.com> | 2014-12-24 14:06:05 -0700 |
commit | 9292c8f405b0ed208443df0b1f9ebd497bb518ab (patch) | |
tree | a1f44a7975b860c5c431cb46a668d5897d2a5fd3 /src/modules/systemlib/perf_counter.c | |
parent | 92eb637d00dc7bec347ddb6d2ddfd90bb27a0b34 (diff) | |
download | px4-firmware-9292c8f405b0ed208443df0b1f9ebd497bb518ab.tar.gz px4-firmware-9292c8f405b0ed208443df0b1f9ebd497bb518ab.tar.bz2 px4-firmware-9292c8f405b0ed208443df0b1f9ebd497bb518ab.zip |
add interrupt latency printout command and mean/variance to interval performance counter
Diffstat (limited to 'src/modules/systemlib/perf_counter.c')
-rw-r--r-- | src/modules/systemlib/perf_counter.c | 53 |
1 files changed, 42 insertions, 11 deletions
diff --git a/src/modules/systemlib/perf_counter.c b/src/modules/systemlib/perf_counter.c index d6d8284d2..f9e90652d 100644 --- a/src/modules/systemlib/perf_counter.c +++ b/src/modules/systemlib/perf_counter.c @@ -41,7 +41,7 @@ #include <stdio.h> #include <sys/queue.h> #include <drivers/drv_hrt.h> - +#include <math.h> #include "perf_counter.h" /** @@ -84,7 +84,8 @@ struct perf_ctr_interval { uint64_t time_last; uint64_t time_least; uint64_t time_most; - + float mean; + float M2; }; /** @@ -109,6 +110,7 @@ perf_alloc(enum perf_counter_type type, const char *name) case PC_INTERVAL: ctr = (perf_counter_t)calloc(sizeof(struct perf_ctr_interval), 1); + break; default: @@ -156,15 +158,23 @@ perf_count(perf_counter_t handle) case 1: pci->time_least = now - pci->time_last; pci->time_most = now - pci->time_last; + pci->mean = pci->time_least / 1e6f; + pci->M2 = 0; break; default: { - hrt_abstime interval = now - pci->time_last; - if (interval < pci->time_least) - pci->time_least = interval; - if (interval > pci->time_most) - pci->time_most = interval; - break; - } + hrt_abstime interval = now - pci->time_last; + if (interval < pci->time_least) + pci->time_least = interval; + if (interval > pci->time_most) + pci->time_most = interval; + // maintain mean and variance of interval in seconds + // Knuth/Welford recursive mean and variance of update intervals (via Wikipedia) + float dt = interval / 1e6f; + float delta_intvl = dt - pci->mean; + pci->mean += delta_intvl / pci->event_count; + pci->M2 += delta_intvl * (dt - pci->mean); + break; + } } pci->time_last = now; pci->event_count++; @@ -313,13 +323,16 @@ perf_print_counter_fd(int fd, perf_counter_t handle) case PC_INTERVAL: { struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle; + float rms = sqrtf(pci->M2 / (pci->event_count-1)); - dprintf(fd, "%s: %llu events, %lluus avg, min %lluus max %lluus\n", + dprintf(fd, "%s: %llu events, %lluus avg, min %lluus max %lluus %5.3f msec mean %5.3f msec rms\n", handle->name, pci->event_count, (pci->time_last - pci->time_first) / pci->event_count, pci->time_least, - pci->time_most); + pci->time_most, + (double)(1000 * pci->mean), + (double)(1000 * rms)); break; } @@ -365,6 +378,21 @@ perf_print_all(int fd) } } +extern const uint16_t latency_bucket_count; +extern uint32_t latency_counters[]; +extern const uint16_t latency_buckets[]; + +void +perf_print_latency(int fd) +{ + dprintf(fd, "bucket : events\n"); + for (int i = 0; i < latency_bucket_count; i++) { + printf(" %4i : %i\n", latency_buckets[i], latency_counters[i]); + } + // print the overflow bucket value + dprintf(fd, " >%4i : %i\n", latency_buckets[latency_bucket_count-1], latency_counters[latency_bucket_count]); +} + void perf_reset_all(void) { @@ -374,4 +402,7 @@ perf_reset_all(void) perf_reset(handle); handle = (perf_counter_t)sq_next(&handle->link); } + for (int i = 0; i <= latency_bucket_count; i++) { + latency_counters[i] = 0; + } } |