Optimisation: only update added library in tracepoint.c

[lttng-ust.git] / liblttng-ust / tracepoint.c

diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c
index a93f286364550e1cf29a3388fa2f5b4a09d5adbf..e3e83b87c1c9ec3678a87f35723d60c95c7e54be 100644 (file)
--- a/liblttng-ust/tracepoint.c
+++ b/liblttng-ust/tracepoint.c
@@ -38,7 +38,7 @@
 #include <helper.h>
 
 #include "tracepoint-internal.h"
-#include "ltt-tracer-core.h"
+#include "lttng-tracer-core.h"
 #include "jhash.h"
 #include "error.h"
 
@@ -78,7 +78,7 @@ static CDS_LIST_HEAD(libs);
  * Tracepoint hash table, containing the active tracepoints.
  * Protected by tracepoint mutex.
  */
-#define TRACEPOINT_HASH_BITS 6
+#define TRACEPOINT_HASH_BITS 12
 #define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS)
 static struct cds_hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
 
@@ -138,13 +138,15 @@ static void debug_print_probes(struct tracepoint_entry *entry)
 
 static void *
 tracepoint_entry_add_probe(struct tracepoint_entry *entry,
-                          void *probe, void *data)
+                          void (*probe)(void), void *data)
 {
        int nr_probes = 0;
        struct tracepoint_probe *old, *new;
 
-       WARN_ON(!probe);
-
+       if (!probe) {
+               WARN_ON(1);
+               return ERR_PTR(-EINVAL);
+       }
        debug_print_probes(entry);
        old = entry->probes;
        if (old) {
@@ -170,8 +172,8 @@ tracepoint_entry_add_probe(struct tracepoint_entry *entry,
 }
 
 static void *
-tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe,
-                             void *data)
+tracepoint_entry_remove_probe(struct tracepoint_entry *entry,
+                             void (*probe)(void), void *data)
 {
        int nr_probes = 0, nr_del = 0, i;
        struct tracepoint_probe *old, *new;
@@ -183,11 +185,12 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe,
 
        debug_print_probes(entry);
        /* (N -> M), (N > 1, M >= 0) probes */
-       for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
-               if (!probe ||
-                    (old[nr_probes].func == probe &&
-                    old[nr_probes].data == data))
-                       nr_del++;
+       if (probe) {
+               for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
+                       if (old[nr_probes].func == probe &&
+                            old[nr_probes].data == data)
+                               nr_del++;
+               }
        }
 
        if (nr_probes - nr_del == 0) {
@@ -204,8 +207,7 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe,
                if (new == NULL)
                        return ERR_PTR(-ENOMEM);
                for (i = 0; old[i].func; i++)
-                       if (probe &&
-                           (old[i].func != probe || old[i].data != data))
+                       if (old[i].func != probe || old[i].data != data)
                                new[j++] = old[i];
                new[nr_probes - nr_del].func = NULL;
                entry->refcount = nr_probes - nr_del;
@@ -371,14 +373,10 @@ void tracepoint_update_probe_range(struct tracepoint * const *begin,
        }
 }
 
-static void lib_update_tracepoints(void)
+static void lib_update_tracepoints(struct tracepoint_lib *lib)
 {
-       struct tracepoint_lib *lib;
-
-       cds_list_for_each_entry(lib, &libs, list) {
-               tracepoint_update_probe_range(lib->tracepoints_start,
-                               lib->tracepoints_start + lib->tracepoints_count);
-       }
+       tracepoint_update_probe_range(lib->tracepoints_start,
+                       lib->tracepoints_start + lib->tracepoints_count);
 }
 
 /*
@@ -386,12 +384,15 @@ static void lib_update_tracepoints(void)
  */
 static void tracepoint_update_probes(void)
 {
+       struct tracepoint_lib *lib;
+
        /* tracepoints registered from libraries and executable. */
-       lib_update_tracepoints();
+       cds_list_for_each_entry(lib, &libs, list)
+               lib_update_tracepoints(lib);
 }
 
 static struct tracepoint_probe *
-tracepoint_add_probe(const char *name, void *probe, void *data,
+tracepoint_add_probe(const char *name, void (*probe)(void), void *data,
                const char *signature)
 {
        struct tracepoint_entry *entry;
@@ -418,8 +419,8 @@ tracepoint_add_probe(const char *name, void *probe, void *data,
  * The probe address must at least be aligned on the architecture pointer size.
  * Called with the tracepoint mutex held.
  */
-int __tracepoint_probe_register(const char *name, void *probe, void *data,
-               const char *signature)
+int __tracepoint_probe_register(const char *name, void (*probe)(void),
+               void *data, const char *signature)
 {
        void *old;
        int ret = 0;
@@ -440,7 +441,8 @@ end:
        return ret;
 }
 
-static void *tracepoint_remove_probe(const char *name, void *probe, void *data)
+static void *tracepoint_remove_probe(const char *name, void (*probe)(void),
+               void *data)
 {
        struct tracepoint_entry *entry;
        void *old;
@@ -462,7 +464,8 @@ static void *tracepoint_remove_probe(const char *name, void *probe, void *data)
  * @probe: probe function pointer
  * @probe: probe data pointer
  */
-int __tracepoint_probe_unregister(const char *name, void *probe, void *data)
+int __tracepoint_probe_unregister(const char *name, void (*probe)(void),
+               void *data)
 {
        void *old;
        int ret = 0;
@@ -499,7 +502,7 @@ static void tracepoint_add_old_probes(void *old)
  *
  * caller must call tracepoint_probe_update_all()
  */
-int tracepoint_probe_register_noupdate(const char *name, void *probe,
+int tracepoint_probe_register_noupdate(const char *name, void (*probe)(void),
                                       void *data, const char *signature)
 {
        void *old;
@@ -525,7 +528,7 @@ end:
  * caller must call tracepoint_probe_update_all()
  * Called with the tracepoint mutex held.
  */
-int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
+int tracepoint_probe_unregister_noupdate(const char *name, void (*probe)(void),
                                         void *data)
 {
        void *old;
@@ -631,8 +634,7 @@ int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
 lib_added:
        new_tracepoints(tracepoints_start, tracepoints_start + tracepoints_count);
 
-       /* TODO: update just the loaded lib */
-       lib_update_tracepoints();
+       lib_update_tracepoints(pl);
        pthread_mutex_unlock(&tracepoint_mutex);
 
        DBG("just registered a tracepoints section from %p and having %d tracepoints",