This commit changes the "ovs-appclt coverage/show" command to show the
per-second, per-minute and per-hour rates of function invocation. More
importantly, this makes using coverage counter an easy way to monitor
the execution of specific functions.
Signed-off-by: Alex Wang <al...@nicira.com>
---
Possible Issue:
The "coverage_run" runs every second. And the number of addition operations is
not very large. If it is still considered to be time-consuming, I'll adjust
further.
---
lib/coverage-unixctl.man | 3 +-
lib/coverage.c | 76 +++++++++++++++++++++++++++++++++++++---------
lib/coverage.h | 33 +++++++++++++++++---
lib/timeval.c | 1 -
vswitchd/ovs-vswitchd.c | 3 ++
5 files changed, 96 insertions(+), 20 deletions(-)
diff --git a/lib/coverage-unixctl.man b/lib/coverage-unixctl.man
index 9718894..2d283dc 100644
--- a/lib/coverage-unixctl.man
+++ b/lib/coverage-unixctl.man
@@ -8,4 +8,5 @@ main loop takes unusually long to run.
Coverage counters are useful mainly for performance analysis and
debugging.
.IP "\fBcoverage/show\fR"
-Displays the values of all of the coverage counters.
+Displays the per-second, per-minute and per-hour rates, and total count
+of all of the coverage counters.
diff --git a/lib/coverage.c b/lib/coverage.c
index f152474..814c741 100644
--- a/lib/coverage.c
+++ b/lib/coverage.c
@@ -47,7 +47,19 @@ struct coverage_counter *coverage_counters[] = {
#define n_coverage_counters ARRAY_SIZE(coverage_counters)
#endif /* !USE_LINKER_SECTIONS */
-static unsigned int epoch;
+/* Makes coverage_run run every second. */
+#define COVERAGE_WAKEUP_INTERVAL 1000
+static long long int coverage_wakeup_timer = LLONG_MIN;
+
+#define HR_TIME 3600 /* 3600 seconds in one hour. */
+
+/* Defines the moving average array index variables. */
+static unsigned int mov_avg_sec_idx = 0;
+static unsigned int mov_avg_min_idx = 0;
+static unsigned int mov_avg_hr_idx = 0;
+
+/* Index counter used to compute the moving average array's index. */
+static unsigned int idx_count = 0;
static void coverage_read(struct svec *);
@@ -170,7 +182,7 @@ coverage_log(void)
uint32_t hash = coverage_hash();
if (coverage_hit(hash)) {
VLOG_INFO("Skipping details of duplicate event coverage for "
- "hash=%08"PRIx32" in epoch %u", hash, epoch);
+ "hash=%08"PRIx32, hash);
} else {
struct svec lines;
const char *line;
@@ -189,8 +201,17 @@ coverage_log(void)
static void
coverage_read_counter(struct svec *lines, const struct coverage_counter *c)
{
- svec_add_nocopy(lines, xasprintf("%-24s %5u / %9llu",
- c->name, c->count, c->count + c->total));
+ /* The per second rate is calculated via averaging the counts in recent
+ * five seconds. */
+ svec_add_nocopy(lines,
+ xasprintf("%-24s %5.1f/sec %7u/min "
+ "%9u/hr total: %llu",
+ c->name,
+ coverage_array_sum(c->mov_avg_sec, MOV_AVG_SEC_LEN)
+ / (float) MOV_AVG_SEC_LEN,
+ coverage_array_sum(c->mov_avg_min, MOV_AVG_MIN_LEN),
+ coverage_array_sum(c->mov_avg_hr, MOV_AVG_HR_LEN),
+ c->count + c->total));
}
/* Adds coverage counter information to 'lines'. */
@@ -204,8 +225,8 @@ coverage_read(struct svec *lines)
hash = coverage_hash();
n_never_hit = 0;
- svec_add_nocopy(lines, xasprintf("Event coverage (epoch %u/entire run), "
- "hash=%08"PRIx32":", epoch, hash));
+ svec_add_nocopy(lines, xasprintf("Event coverage (frequency), "
+ "hash=%08"PRIx32":", hash));
for (i = 0; i < n_coverage_counters; i++) {
struct coverage_counter *c = coverage_counters[i];
if (c->count) {
@@ -225,16 +246,43 @@ coverage_read(struct svec *lines)
svec_add_nocopy(lines, xasprintf("%zu events never hit", n_never_hit));
}
-/* Advances to the next epoch of coverage, resetting all the counters to 0. */
+/* Causes the following call to poll_block() to wake up every second. */
void
-coverage_clear(void)
+coverage_wait(void)
{
- size_t i;
+ poll_timer_wait_until(coverage_wakeup_timer);
+}
- epoch++;
- for (i = 0; i < n_coverage_counters; i++) {
- struct coverage_counter *c = coverage_counters[i];
- c->total += c->count;
- c->count = 0;
+/* Runs every second to update the coverage counters' mov_avg_sec array,
+ * mov_avg_min array and mov_avg_hr array. */
+void
+coverage_run(void)
+{
+ if (time_msec() >= coverage_wakeup_timer) {
+ size_t i;
+
+ /* Updates the index variables. */
+ mov_avg_sec_idx = idx_count % MOV_AVG_SEC_LEN;
+ mov_avg_min_idx = (idx_count / MOV_AVG_SEC_LEN) % MOV_AVG_MIN_LEN;
+ mov_avg_hr_idx = idx_count / MOV_AVG_HR_LEN;
+
+ for (i = 0; i < n_coverage_counters; i++) {
+ struct coverage_counter *c = coverage_counters[i];
+
+ c->total += c->count;
+ c->mov_avg_sec[mov_avg_sec_idx] = c->count;
+ /* Note, only adds up the latest count here. */
+ c->mov_avg_min[mov_avg_min_idx] = mov_avg_sec_idx == 0 ?
+ c->count : (c->mov_avg_min[mov_avg_min_idx] + c->count);
+ /* The summation here is for fast sync change to per-hour rate.
+ * should be modified when it becomes very time consuming. */
+ c->mov_avg_hr[mov_avg_hr_idx] =
+ coverage_array_sum(c->mov_avg_min, mov_avg_min_idx + 1);
+ c->count = 0;
+ }
+
+ /* Always updates the wakeup timer and idx_count. */
+ coverage_wakeup_timer = time_msec() + COVERAGE_WAKEUP_INTERVAL;
+ idx_count = (idx_count + 1) % HR_TIME;
}
}
diff --git a/lib/coverage.h b/lib/coverage.h
index 968c489..60c5107 100644
--- a/lib/coverage.h
+++ b/lib/coverage.h
@@ -27,13 +27,24 @@
* for traditional coverage instrumentation with e.g. "gcov", but it is still
* a useful debugging tool. */
+#include "poll-loop.h"
#include "vlog.h"
+/* Defines the moving average array length. */
+#define MOV_AVG_SEC_LEN 5 /* 1 * 5 second = 5 seconds */
+#define MOV_AVG_MIN_LEN 12 /* 12 * 5 seconds = 1 minute */
+#define MOV_AVG_HR_LEN 60 /* 60 * 1 minute = 1 hour */
+
/* A coverage counter. */
struct coverage_counter {
const char *name; /* Textual name. */
- unsigned int count; /* Count within the current epoch. */
- unsigned long long int total; /* Total count over all epochs. */
+ unsigned int count; /* Count within the current second. */
+ unsigned long long int total; /* Total count over all time. */
+
+ /* The moving average arrays. */
+ unsigned int mov_avg_sec[MOV_AVG_SEC_LEN];
+ unsigned int mov_avg_min[MOV_AVG_MIN_LEN];
+ unsigned int mov_avg_hr[MOV_AVG_HR_LEN];
};
/* Defines COUNTER. There must be exactly one such definition at file scope
@@ -57,11 +68,25 @@ struct coverage_counter {
void coverage_init(void);
void coverage_log(void);
-void coverage_clear(void);
+void coverage_wait(void);
+void coverage_run(void);
+
+static inline unsigned int
+coverage_array_sum(const unsigned int arr[], unsigned int len)
+{
+ unsigned int sum = 0;
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ sum += arr[i];
+ }
+ return sum;
+}
/* Implementation detail. */
#define COVERAGE_DEFINE__(COUNTER) \
extern struct coverage_counter counter_##COUNTER; \
- struct coverage_counter counter_##COUNTER = { #COUNTER, 0, 0 }
+ struct coverage_counter counter_##COUNTER = { #COUNTER, 0, 0, \
+ {0}, {0}, {0} }
#endif /* coverage.h */
diff --git a/lib/timeval.c b/lib/timeval.c
index 5ff59bc..fe4f2a7 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -333,7 +333,6 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long
int timeout_when,
if (last_wakeup) {
log_poll_interval(last_wakeup);
}
- coverage_clear();
start = time_msec();
blocked = false;
diff --git a/vswitchd/ovs-vswitchd.c b/vswitchd/ovs-vswitchd.c
index e11febd..9bf4664 100644
--- a/vswitchd/ovs-vswitchd.c
+++ b/vswitchd/ovs-vswitchd.c
@@ -28,6 +28,7 @@
#include "bridge.h"
#include "command-line.h"
#include "compiler.h"
+#include "coverage.h"
#include "daemon.h"
#include "dirs.h"
#include "dpif.h"
@@ -126,6 +127,7 @@ main(int argc, char *argv[])
bridge_run_fast();
unixctl_server_run(unixctl);
netdev_run();
+ coverage_run();
worker_wait();
signal_wait(sighup);
@@ -133,6 +135,7 @@ main(int argc, char *argv[])
bridge_wait();
unixctl_server_wait(unixctl);
netdev_wait();
+ coverage_wait();
if (exiting) {
poll_immediate_wake();
}
--
1.7.9.5
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