diff mbox series

[v2,1/2] lttng_ust_init_thread: initialise cached context values

Message ID 20220801143700.160380-1-norbert.lange@andritz.com
State New
Headers show
Series [v2,1/2] lttng_ust_init_thread: initialise cached context values | expand

Commit Message

Norbert Lange Aug. 1, 2022, 2:36 p.m. UTC 
From: Norbert Lange <nolange79 at gmail.com>

Modify all relevant *_alloc_tls functions so that they take
flags for 'init'. Rename them to init_thread for consistency.

So far define one flag LTTNG_UST_INIT_THREAD_CONTEXT_CACHE,
this will warm up cached values so less is done during
the first tracepoint.

The function 'lttng_ust_init_thread' will use all available
flags, software can opt-in to do work early instead
of lazily during tracepoints.

Signed-off-by: Norbert Lange <nolange79 at gmail.com>
---
v1 -> v2:

*   instead of a bool, use a flag variable
*   try to improve consistency for some funciton names

v1:

*   see https://lore.kernel.org/all/CADYdroN3=pAe66crtsVT9aHE4T+bT61-tvHFKCuwZYkHhuyFjw at mail.gmail.com/
*   Will update docs after review, and do some more tests
    during the week
---
 src/lib/lttng-ust/lttng-context-cgroup-ns.c   |  4 ++-
 src/lib/lttng-ust/lttng-context-ipc-ns.c      |  4 ++-
 src/lib/lttng-ust/lttng-context-net-ns.c      |  4 ++-
 .../lttng-ust/lttng-context-perf-counters.c   |  3 +-
 src/lib/lttng-ust/lttng-context-procname.c    |  4 ++-
 src/lib/lttng-ust/lttng-context-provider.c    |  4 +--
 src/lib/lttng-ust/lttng-context-time-ns.c     |  4 ++-
 src/lib/lttng-ust/lttng-context-uts-ns.c      |  4 ++-
 src/lib/lttng-ust/lttng-context-vtid.c        |  4 ++-
 src/lib/lttng-ust/lttng-probes.c              |  4 +--
 src/lib/lttng-ust/lttng-tracer-core.h         | 26 ++++++++------
 src/lib/lttng-ust/lttng-ust-comm.c            | 34 +++++++++----------
 src/lib/lttng-ust/lttng-ust-statedump.c       |  2 +-
 13 files changed, 61 insertions(+), 40 deletions(-)

Comments

Mathieu Desnoyers Aug. 1, 2022, 3:11 p.m. UTC | #1 
----- On Aug 1, 2022, at 10:36 AM, Norbert Lange via lttng-dev lttng-dev at lists.lttng.org wrote:

> #else /* #ifdef HAVE_LINUX_PERF_EVENT_H */
> static inline
> -void lttng_ust_perf_counter_alloc_tls(void)
> +void lttng_ust_perf_counter_init_thread(int flags)

Using 

void lttng_ust_perf_counter_init_thread(int flags __attribute__((unused)))

instead.

> {
> +	(void)flags;
> }

Will fixup locally and merge.

Thanks,

Mathieu
diff mbox series

Patch

diff --git a/src/lib/lttng-ust/lttng-context-cgroup-ns.c b/src/lib/lttng-ust/lttng-context-cgroup-ns.c
index 34523ea1..5accd2df 100644
--- a/src/lib/lttng-ust/lttng-context-cgroup-ns.c
+++ b/src/lib/lttng-ust/lttng-context-cgroup-ns.c
@@ -155,7 +155,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_cgroup_ns_alloc_tls(void)
+void lttng_ust_cgroup_ns_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_cgroup_ns)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)get_cgroup_ns();
 }
diff --git a/src/lib/lttng-ust/lttng-context-ipc-ns.c b/src/lib/lttng-ust/lttng-context-ipc-ns.c
index 63401e8d..078e6461 100644
--- a/src/lib/lttng-ust/lttng-context-ipc-ns.c
+++ b/src/lib/lttng-ust/lttng-context-ipc-ns.c
@@ -153,7 +153,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_ipc_ns_alloc_tls(void)
+void lttng_ust_ipc_ns_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_ipc_ns)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)get_ipc_ns();
 }
diff --git a/src/lib/lttng-ust/lttng-context-net-ns.c b/src/lib/lttng-ust/lttng-context-net-ns.c
index 960591c2..66fcb045 100644
--- a/src/lib/lttng-ust/lttng-context-net-ns.c
+++ b/src/lib/lttng-ust/lttng-context-net-ns.c
@@ -153,7 +153,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_net_ns_alloc_tls(void)
+void lttng_ust_net_ns_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_net_ns)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)get_net_ns();
 }
diff --git a/src/lib/lttng-ust/lttng-context-perf-counters.c b/src/lib/lttng-ust/lttng-context-perf-counters.c
index 2db11436..52371a0d 100644
--- a/src/lib/lttng-ust/lttng-context-perf-counters.c
+++ b/src/lib/lttng-ust/lttng-context-perf-counters.c
@@ -87,9 +87,10 @@  static DEFINE_URCU_TLS(int, ust_perf_mutex_nest);
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_ust_perf_counter_alloc_tls(void)
+void lttng_ust_perf_counter_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest)));
+	(void)flags;
 }
 
 void lttng_perf_lock(void)
diff --git a/src/lib/lttng-ust/lttng-context-procname.c b/src/lib/lttng-ust/lttng-context-procname.c
index b5bf77be..16f34c46 100644
--- a/src/lib/lttng-ust/lttng-context-procname.c
+++ b/src/lib/lttng-ust/lttng-context-procname.c
@@ -122,7 +122,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_procname_alloc_tls(void)
+void lttng_ust_procname_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_procname)[0]));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)wrapper_getprocname();
 }
diff --git a/src/lib/lttng-ust/lttng-context-provider.c b/src/lib/lttng-ust/lttng-context-provider.c
index 4e7e429f..5000657d 100644
--- a/src/lib/lttng-ust/lttng-context-provider.c
+++ b/src/lib/lttng-ust/lttng-context-provider.c
@@ -67,7 +67,7 @@  struct lttng_ust_registered_context_provider *lttng_ust_context_provider_registe
 	size_t name_len = strlen(provider->name);
 	uint32_t hash;
 
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	/* Provider name starts with "$app.". */
 	if (strncmp("$app.", provider->name, strlen("$app.")) != 0)
@@ -101,7 +101,7 @@  end:
 
 void lttng_ust_context_provider_unregister(struct lttng_ust_registered_context_provider *reg_provider)
 {
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	if (ust_lock())
 		goto end;
diff --git a/src/lib/lttng-ust/lttng-context-time-ns.c b/src/lib/lttng-ust/lttng-context-time-ns.c
index ec32a1de..e84b7048 100644
--- a/src/lib/lttng-ust/lttng-context-time-ns.c
+++ b/src/lib/lttng-ust/lttng-context-time-ns.c
@@ -152,7 +152,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_time_ns_alloc_tls(void)
+void lttng_ust_time_ns_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_time_ns)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)get_time_ns();
 }
diff --git a/src/lib/lttng-ust/lttng-context-uts-ns.c b/src/lib/lttng-ust/lttng-context-uts-ns.c
index 06a978fd..51d6092e 100644
--- a/src/lib/lttng-ust/lttng-context-uts-ns.c
+++ b/src/lib/lttng-ust/lttng-context-uts-ns.c
@@ -154,7 +154,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_uts_ns_alloc_tls(void)
+void lttng_ust_uts_ns_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_uts_ns)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)get_uts_ns();
 }
diff --git a/src/lib/lttng-ust/lttng-context-vtid.c b/src/lib/lttng-ust/lttng-context-vtid.c
index 880e34b9..e9bbbf85 100644
--- a/src/lib/lttng-ust/lttng-context-vtid.c
+++ b/src/lib/lttng-ust/lttng-context-vtid.c
@@ -112,7 +112,9 @@  error_find_context:
 /*
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
-void lttng_vtid_alloc_tls(void)
+void lttng_ust_vtid_init_thread(int flags)
 {
 	asm volatile ("" : : "m" (URCU_TLS(cached_vtid)));
+	if (flags & LTTNG_UST_INIT_THREAD_CONTEXT_CACHE)
+		(void)wrapper_getvtid();
 }
diff --git a/src/lib/lttng-ust/lttng-probes.c b/src/lib/lttng-ust/lttng-probes.c
index e8e08ff1..2d47bf19 100644
--- a/src/lib/lttng-ust/lttng-probes.c
+++ b/src/lib/lttng-ust/lttng-probes.c
@@ -231,7 +231,7 @@  struct lttng_ust_registered_probe *lttng_ust_probe_register(const struct lttng_u
 {
 	struct lttng_ust_registered_probe *reg_probe = NULL;
 
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	/*
 	 * If version mismatch, don't register, but don't trigger assert
@@ -269,7 +269,7 @@  end:
 
 void lttng_ust_probe_unregister(struct lttng_ust_registered_probe *reg_probe)
 {
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	if (!reg_probe)
 		return;
diff --git a/src/lib/lttng-ust/lttng-tracer-core.h b/src/lib/lttng-ust/lttng-tracer-core.h
index eadc43ed..dd83a323 100644
--- a/src/lib/lttng-ust/lttng-tracer-core.h
+++ b/src/lib/lttng-ust/lttng-tracer-core.h
@@ -16,6 +16,11 @@ 
 #include <lttng/ust-ringbuffer-context.h>
 #include "common/logging.h"
 
+enum lttng_ust_init_thread_flags {
+	LTTNG_UST_INIT_THREAD_CONTEXT_CACHE = (1 << 0),
+	LTTNG_UST_INIT_THREAD_MASK = (LTTNG_UST_INIT_THREAD_CONTEXT_CACHE << 1) - 1,
+};
+
 struct lttng_ust_session;
 struct lttng_ust_channel_buffer;
 struct lttng_ust_ctx_field;
@@ -34,28 +39,28 @@  void ust_lock_nocheck(void)
 void ust_unlock(void)
 	__attribute__((visibility("hidden")));
 
-void lttng_ust_alloc_tls(void)
+void lttng_ust_common_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_vtid_alloc_tls(void)
+void lttng_ust_vtid_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_procname_alloc_tls(void)
+void lttng_ust_procname_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_cgroup_ns_alloc_tls(void)
+void lttng_ust_cgroup_ns_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_ipc_ns_alloc_tls(void)
+void lttng_ust_ipc_ns_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_net_ns_alloc_tls(void)
+void lttng_ust_net_ns_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_time_ns_alloc_tls(void)
+void lttng_ust_time_ns_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
-void lttng_uts_ns_alloc_tls(void)
+void lttng_ust_uts_ns_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
 const char *lttng_ust_obj_get_name(int id)
@@ -78,7 +83,7 @@  void lttng_event_notifier_notification_send(
 	__attribute__((visibility("hidden")));
 
 #ifdef HAVE_LINUX_PERF_EVENT_H
-void lttng_ust_perf_counter_alloc_tls(void)
+void lttng_ust_perf_counter_init_thread(int flags)
 	__attribute__((visibility("hidden")));
 
 void lttng_perf_lock(void)
@@ -88,8 +93,9 @@  void lttng_perf_unlock(void)
 	__attribute__((visibility("hidden")));
 #else /* #ifdef HAVE_LINUX_PERF_EVENT_H */
 static inline
-void lttng_ust_perf_counter_alloc_tls(void)
+void lttng_ust_perf_counter_init_thread(int flags)
 {
+	(void)flags;
 }
 static inline
 void lttng_perf_lock(void)
diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c
index 7f34efe7..0a039fef 100644
--- a/src/lib/lttng-ust/lttng-ust-comm.c
+++ b/src/lib/lttng-ust/lttng-ust-comm.c
@@ -387,7 +387,7 @@  const char *get_lttng_home_dir(void)
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
 static
-void lttng_nest_count_alloc_tls(void)
+void lttng_ust_nest_count_alloc_tls(void)
 {
 	asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count)));
 }
@@ -402,26 +402,26 @@  void lttng_ust_mutex_nest_alloc_tls(void)
  * Allocate lttng-ust urcu TLS.
  */
 static
-void lttng_lttng_ust_urcu_alloc_tls(void)
+void lttng_ust_urcu_alloc_tls(void)
 {
 	(void) lttng_ust_urcu_read_ongoing();
 }
 
-void lttng_ust_alloc_tls(void)
+void lttng_ust_common_init_thread(int flags)
 {
-	lttng_lttng_ust_urcu_alloc_tls();
+	lttng_ust_urcu_alloc_tls();
 	lttng_ringbuffer_alloc_tls();
-	lttng_vtid_alloc_tls();
-	lttng_nest_count_alloc_tls();
-	lttng_procname_alloc_tls();
+	lttng_ust_vtid_init_thread(flags);
+	lttng_ust_nest_count_alloc_tls();
+	lttng_ust_procname_init_thread(flags);
 	lttng_ust_mutex_nest_alloc_tls();
-	lttng_ust_perf_counter_alloc_tls();
+	lttng_ust_perf_counter_init_thread(flags);
 	lttng_ust_common_alloc_tls();
-	lttng_cgroup_ns_alloc_tls();
-	lttng_ipc_ns_alloc_tls();
-	lttng_net_ns_alloc_tls();
-	lttng_time_ns_alloc_tls();
-	lttng_uts_ns_alloc_tls();
+	lttng_ust_cgroup_ns_init_thread(flags);
+	lttng_ust_ipc_ns_init_thread(flags);
+	lttng_ust_net_ns_init_thread(flags);
+	lttng_ust_time_ns_init_thread(flags);
+	lttng_ust_uts_ns_init_thread(flags);
 	lttng_ust_ring_buffer_client_discard_alloc_tls();
 	lttng_ust_ring_buffer_client_discard_rt_alloc_tls();
 	lttng_ust_ring_buffer_client_overwrite_alloc_tls();
@@ -446,7 +446,7 @@  void lttng_ust_init_thread(void)
 	 * ensure those are initialized before a signal handler nesting over
 	 * this thread attempts to use them.
 	 */
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(LTTNG_UST_INIT_THREAD_MASK);
 }
 
 int lttng_get_notify_socket(void *owner)
@@ -1815,7 +1815,7 @@  void *ust_listener_thread(void *arg)
 	int sock, ret, prev_connect_failed = 0, has_waited = 0, fd;
 	long timeout;
 
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 	/*
 	 * If available, add '-ust' to the end of this thread's
 	 * process name
@@ -2183,7 +2183,7 @@  void lttng_ust_ctor(void)
 	 * to be the dynamic linker mutex) and ust_lock, taken within
 	 * the ust lock.
 	 */
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	lttng_ust_loaded = 1;
 
@@ -2497,7 +2497,7 @@  void lttng_ust_before_fork(sigset_t *save_sigset)
 	int ret;
 
 	/* Allocate lttng-ust TLS. */
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	if (URCU_TLS(lttng_ust_nest_count))
 		return;
diff --git a/src/lib/lttng-ust/lttng-ust-statedump.c b/src/lib/lttng-ust/lttng-ust-statedump.c
index 309a98fa..bd95c043 100644
--- a/src/lib/lttng-ust/lttng-ust-statedump.c
+++ b/src/lib/lttng-ust/lttng-ust-statedump.c
@@ -557,7 +557,7 @@  void lttng_ust_dl_update(void *ip)
 	 * Force the allocation of lttng-ust TLS variables when called from
 	 * dlopen/dlclose instrumentation.
 	 */
-	lttng_ust_alloc_tls();
+	lttng_ust_common_init_thread(0);
 
 	data.exec_found = 0;
 	data.first = true;