于 2012年08月31日 02:29, David Ahern 写道:
In addition to Andrew's comment about making the stats struct and
functions generic...
Yes. :-)
On 8/27/12 3:51 AM, Dong Hao wrote:
---8<---
+static void exit_event_decode_key(struct event_key *key, char
decode[20])
+{
+ const char *exit_reason = get_exit_reason(key->key);
+
+ snprintf(decode, 20, "%s", exit_reason);
+}
Use scnprintf rather than snprintf.
Why? Since we don't care about the return value, what's the difference?
---8<---
+static bool kvm_event_expand(struct kvm_event *event, int vcpu_id)
+{
+ int old_max_vcpu = event->max_vcpu;
+
+ if (vcpu_id < event->max_vcpu)
+ return true;
+
+ while (event->max_vcpu <= vcpu_id)
+ event->max_vcpu += DEFAULT_VCPU_NUM;
+
+ event->vcpu = realloc(event->vcpu,
+ event->max_vcpu * sizeof(*event->vcpu));
+ if (!event->vcpu) {
If realloc fails you leak memory by overwriting the current pointer.
Thanks for pointing it out, we will terminate the running instance in
our next
version.
---8<---
+static double event_stats_stddev(int vcpu_id, struct kvm_event *event)
+{
+ struct event_stats *stats = &event->total;
+ double variance, variance_mean, stddev;
+
+ if (vcpu_id != -1)
+ stats = &event->vcpu[vcpu_id];
+
+ BUG_ON(!stats->count);
+
+ variance = stats->M2 / (stats->count - 1);
+ variance_mean = variance / stats->count;
+ stddev = sqrt(variance_mean);
+
+ return stddev * 100 / stats->mean;
+}
perf should be consistent in the stddev it shows the user. Any reason
to dump relative stddev versus stddev used by perf-stat?
Since 'perf stat' uses relative standard deviation rather than stddev,
'perf kvm stat'
just follows the style of 'perf stat'.
---8<---
+/* returns left most element of result, and erase it */
+static struct kvm_event *pop_from_result(void)
+{
+ struct rb_node *node = result.rb_node;
+
+ if (!node)
+ return NULL;
+
+ while (node->rb_left)
+ node = node->rb_left;
Use rb_first().
OK, we will use it in the next version.
---8<---
+ /*
+ * Append "-a" only if "-p"/"--pid" is not specified since they
+ * are mutually exclusive.
+ */
+ if (!kvm_record_specified_guest(argc, argv))
+ rec_argv[i++] = STRDUP_FAIL_EXIT("-a");
Other perf-kvm commands rely on perf-record semantics -- i.e., for
user to add the -a or -p option.
You mean, remove '-a' from the default options, then:
if a user wants to record all guest he will use 'perf stat record -a';
and if a user wants to record the specified guest, he should use
'perf stat record -p xxx'?
Well, as the style of other subcommand, e.g., perf lock/perf sched, the
'perf xxx record' record all events on all cpus, no need to use '-a'.
Based on mentioned above, I prefer the original way. ;)
---8<---
+static const char * const kvm_events_report_usage[] = {
+ "perf kvm stat report [<options>]",
+ NULL
+};
+
+static const struct option kvm_events_report_options[] = {
+ OPT_STRING(0, "event", &report_event, "report event",
+ "event for reporting: vmexit, mmio, ioport"),
+ OPT_INTEGER(0, "vcpu", &trace_vcpu,
+ "vcpu id to report"),
+ OPT_STRING('k', "key", &sort_key, "sort-key",
+ "key for sorting: sample(sort by samples number)"
+ " time (sort by avg time)"),
+ OPT_END()
+};
+
+static int kvm_events_report(int argc, const char **argv)
+{
+ symbol__init();
+
+ if (argc) {
+ argc = parse_options(argc, argv,
+ kvm_events_report_options,
+ kvm_events_report_usage, 0);
+ if (argc)
+ usage_with_options(kvm_events_report_usage,
+ kvm_events_report_options);
+ }
+
+ return kvm_events_report_vcpu(trace_vcpu);
+}
+
+static int kvm_cmd_stat(int argc, const char **argv)
+{
+ if (argc > 1) {
+ if (!strncmp(argv[1], "rec", 3))
+ return kvm_events_record(argc - 1, argv + 1);
+
+ if (!strncmp(argv[1], "rep", 3))
+ return kvm_events_report(argc - 1 , argv + 1);
+ }
+
+ return cmd_stat(argc, argv, NULL);
+}
+
static char name_buffer[256];
static const char * const kvm_usage[] = {
- "perf kvm [<options>] {top|record|report|diff|buildid-list}",
+ "perf kvm [<options>] {top|record|report|diff|buildid-list|stat}",
NULL
};
The usage for the report/record sub commands of stat is never shown.
e.g.,
$ perf kvm stat
--> shows help for perf-stat
$ perf kvm
--> shows the above and perf-kvm's usage
To get help for the record/report subcommands you have to know that
record and report are subcommands.
Okay, we will improve this.
---8<---
+static int perf_file_section__read_feature(struct perf_file_section
*section,
+ struct perf_header *ph,
+ int feat, int fd, void *data)
+{
+ struct header_read_data *hd = data;
+
+ if (feat != hd->feat)
+ return 0;
+
+ if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
+ pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
+ "%d, continuing...\n", section->offset, feat);
+ return 0;
+ }
+
+ if (feat >= HEADER_LAST_FEATURE) {
+ pr_warning("unknown feature %d\n", feat);
+ return 0;
+ }
+
+ hd->result = feat_ops[feat].read(ph, fd);
you should verify the read() function is implemented for the requested
feature.
OK, thank you for your comments, we will correct it. :-)
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