[PATCH v1 3/5] perf/sdt: Show SDT cache contents

From: Hemant Kumar
Date: Wed Oct 01 2014 - 03:17:10 EST


This patch adds support to dump the SDT cache onto sdtout.
The cache data is read into a hash_list and then, it iterates through
the hash_list to dump the data onto stdout.

# ./perf sdt-cache --dump

/usr/lib64/libc-2.16.so :
%libc:lll_futex_wake
%libc:longjmp_target
%libc:longjmp
%libc:lll_lock_wait_private
%libc:lll_futex_wake
%libc:longjmp_target
%libc:longjmp
%libc:setjmp

Signed-off-by: Hemant Kumar <hemant@xxxxxxxxxxxxxxxxxx>
---
tools/perf/builtin-sdt-cache.c | 26 +++++++++++++++++++++-
tools/perf/util/parse-events.h | 1 +
tools/perf/util/sdt.c | 47 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sdt-cache.c b/tools/perf/builtin-sdt-cache.c
index 3c30829..c4acb91 100644
--- a/tools/perf/builtin-sdt-cache.c
+++ b/tools/perf/builtin-sdt-cache.c
@@ -15,6 +15,7 @@
/* Session management structure */
static struct {
bool add;
+ bool dump;
const char *target;
} params;

@@ -27,6 +28,15 @@ static int opt_add_sdt_events(const struct option *opt __maybe_unused,
return 0;
}

+static int opt_show_sdt_events(const struct option *opt __maybe_unused,
+ const char *str, int unset __maybe_unused)
+{
+ if (str)
+ pr_err("Unknown option %s\n", str);
+ params.dump = true;
+ return 0;
+}
+
int cmd_sdt_cache(int argc, const char **argv, const char *prefix __maybe_unused)
{
int ret;
@@ -34,10 +44,13 @@ int cmd_sdt_cache(int argc, const char **argv, const char *prefix __maybe_unused
OPT_CALLBACK('a', "add", NULL, "filename",
"add SDT events from a file.",
opt_add_sdt_events),
+ OPT_CALLBACK_NOOPT('s', "dump", NULL, "show SDT events",
+ "Read SDT events from cache and display.",
+ opt_show_sdt_events),
OPT_END()
};
const char * const sdt_cache_usage[] = {
- "perf sdt_cache --add filename",
+ "perf sdt_cache [--add filename | --dump]",
NULL
};

@@ -49,9 +62,20 @@ int cmd_sdt_cache(int argc, const char **argv, const char *prefix __maybe_unused

symbol__elf_init();
if (params.add) {
+ if (params.dump) {
+ pr_err("Error: Don't use --dump with --add\n");
+ usage_with_options(sdt_cache_usage, sdt_cache_options);
+ }
ret = add_sdt_events(params.target);
if (ret < 0)
pr_err("Cannot add SDT events to cache!\n");
+ } else if (params.dump) {
+ if (argc == 0) {
+ ret = dump_sdt_events();
+ if (ret < 0)
+ pr_err("Cannot dump SDT event cache!\n");
+ } else
+ usage_with_options(sdt_cache_usage, sdt_cache_options);
} else
usage_with_options(sdt_cache_usage, sdt_cache_options);
return 0;
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index e6efe2c..f43e6aa 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -110,5 +110,6 @@ extern int is_valid_tracepoint(const char *event_string);
extern int valid_debugfs_mount(const char *debugfs);

int add_sdt_events(const char *file);
+int dump_sdt_events(void);

#endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/sdt.c b/tools/perf/util/sdt.c
index 0b56210..8c3a5a5 100644
--- a/tools/perf/util/sdt.c
+++ b/tools/perf/util/sdt.c
@@ -663,3 +663,50 @@ int add_sdt_events(const char *arg)
}
return ret;
}
+
+/**
+ * file_hash_list__display: Dump the entries of file_hash list
+ * @file_hash: file hash list
+ *
+ * Iterate through each of the entries and the chains and dump
+ * onto stdscr.
+ */
+static void file_hash_list__display(struct hash_list *file_hash)
+{
+ struct file_sdt_ent *file_pos;
+ struct list_head *ent_head, *sdt_head;
+ struct sdt_note *sdt_pos;
+ int i;
+
+ for (i = 0; i < HASH_TABLE_SIZE; i++) {
+ /* Get the list_head for this entry */
+ ent_head = &file_hash->ent[i].list;
+ /* No entries ?*/
+ if (list_empty(ent_head))
+ continue;
+
+ /* Iterate through the chain in this entry */
+ list_for_each_entry(file_pos, ent_head, file_list) {
+ printf("%s :\n", file_pos->name);
+ /* Get he SDT events' head */
+ sdt_head = &file_pos->sdt_list;
+ list_for_each_entry(sdt_pos, sdt_head, note_list) {
+ printf("\t%%%s:%s\n", sdt_pos->provider,
+ sdt_pos->name);
+ }
+ printf("\n");
+ }
+ }
+}
+
+/**
+ * dump_sdt_events: Dump the SDT events on stdout
+ */
+int dump_sdt_events(void)
+{
+ struct hash_list file_hash;
+
+ file_hash_list__init(&file_hash);
+ file_hash_list__display(&file_hash);
+ return 0;
+}

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