With this patch, `ovs-appctl backtrace` will return a unique list
of backtraces and a count of how many times it has been recorded.
This work had previously been done by ovs-parse-backtrace. However,
in future patches poll-loop will begin logging backtraces as a
matter of course. At this point, coalescing the backtraces will
help keep these log messages brief.
Signed-off-by: Ethan Jackson <et...@nicira.com>
---
lib/timeval.c | 53 +++++++++++++++++++++++++++++++++++---
utilities/ovs-parse-backtrace.in | 26 ++++++++-----------
2 files changed, 61 insertions(+), 18 deletions(-)
diff --git a/lib/timeval.c b/lib/timeval.c
index e507140..bd2a84d 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -32,6 +32,8 @@
#include "dummy.h"
#include "dynamic-string.h"
#include "fatal-signal.h"
+#include "hash.h"
+#include "hmap.h"
#include "signals.h"
#include "unixctl.h"
#include "util.h"
@@ -72,6 +74,10 @@ static long long int deadline = LLONG_MAX;
struct trace {
void *backtrace[32]; /* Populated by backtrace(). */
size_t n_frames; /* Number of frames in 'backtrace'. */
+
+ /* format_backtraces() helper data. */
+ struct hmap_node node;
+ size_t count;
};
#define MAX_TRACES 50
@@ -577,6 +583,29 @@ get_cpu_usage(void)
return cpu_usage;
}
+static uint32_t
+hash_trace(struct trace *trace)
+{
+ return hash_bytes(trace->backtrace,
+ trace->n_frames * sizeof *trace->backtrace, 0);
+}
+
+static struct trace *
+trace_map_lookup(struct hmap *trace_map, struct trace *key)
+{
+ struct trace *value;
+
+ HMAP_FOR_EACH_WITH_HASH (value, node, hash_trace(key), trace_map) {
+ if (key->n_frames == value->n_frames
+ && !memcmp(key->backtrace, value->backtrace,
+ key->n_frames * sizeof *key->backtrace)) {
+ return value;
+ }
+ }
+ return NULL;
+}
+
+
static void
format_backtraces(struct ds *ds)
{
@@ -584,6 +613,8 @@ format_backtraces(struct ds *ds)
#if HAVE_EXECINFO_H
if (CACHE_TIME) {
+ struct hmap trace_map = HMAP_INITIALIZER(&trace_map);
+ struct trace *trace, *next;
sigset_t oldsigs;
size_t i;
@@ -591,16 +622,30 @@ format_backtraces(struct ds *ds)
for (i = 0; i < MAX_TRACES; i++) {
struct trace *trace = &traces[i];
- char **frame_strs;
- size_t j;
+ struct trace *map_trace;
if (!trace->n_frames) {
continue;
}
+ map_trace = trace_map_lookup(&trace_map, trace);
+ if (map_trace) {
+ map_trace->count++;
+ } else {
+ hmap_insert(&trace_map, &trace->node, hash_trace(trace));
+ trace->count = 1;
+ }
+ }
+
+ HMAP_FOR_EACH_SAFE (trace, next, node, &trace_map) {
+ char **frame_strs;
+ size_t j;
+
+ hmap_remove(&trace_map, &trace->node);
+
frame_strs = backtrace_symbols(trace->backtrace, trace->n_frames);
- ds_put_format(ds, "Backtrace %zu\n", i + 1);
+ ds_put_format(ds, "Count %zu\n", trace->count);
for (j = 0; j < trace->n_frames; j++) {
ds_put_format(ds, "%s\n", frame_strs[j]);
}
@@ -608,6 +653,8 @@ format_backtraces(struct ds *ds)
free(frame_strs);
}
+ hmap_destroy(&trace_map);
+
ds_chomp(ds, '\n');
unblock_sigalrm(&oldsigs);
}
diff --git a/utilities/ovs-parse-backtrace.in b/utilities/ovs-parse-backtrace.in
index 4f793be..350cbd9 100755
--- a/utilities/ovs-parse-backtrace.in
+++ b/utilities/ovs-parse-backtrace.in
@@ -73,23 +73,19 @@ result. Expected usage is for ovs-appctl backtrace to be
piped in.""")
print "Binary: %s\n" % binary
stdin = sys.stdin.read()
- trace_list = stdin.strip().split("\n\n")
- try:
- #Remove the first line from each trace.
- trace_list = [trace[(trace.index("\n") + 1):] for trace in trace_list]
- except ValueError:
- sys.stdout.write(stdin)
- sys.exit(1)
-
- trace_map = {}
- for trace in trace_list:
- trace_map[trace] = trace_map.get(trace, 0) + 1
-
- sorted_traces = sorted(trace_map.items(), key=(lambda x: x[1]),
- reverse=True)
- for trace, count in sorted_traces:
+ traces = []
+ for trace in stdin.strip().split("\n\n"):
lines = trace.splitlines()
+ match = re.search(r'Count (\d+)', lines[0])
+ if match:
+ count = int(match.group(1))
+ else:
+ count = 0
+ traces.append((lines[1:], count))
+ traces = sorted(traces, key=(lambda x: x[1]), reverse=True)
+
+ for lines, count in traces:
longest = max(len(l) for l in lines)
print "Backtrace Count: %d" % count
--
1.7.9.5
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