----- On Jul 18, 2022, at 5:59 PM, Norbert Lange via lttng-dev lttng-dev@lists.lttng.org wrote:
> Modify all relevant *_alloc_tls functions so that they take an > argument for 'init'. Setting this to 'true' will read > the actual context value and store it into a thread local > cache. > > The function 'lttng_ust_init_thread' will use this to > precalculate context values. Tracepoints can then avoid > systemcalls. Rather than integrating two unrelated things within "alloc_tls" functions, I would prefer that we split things like this, e.g.: keep lttng_cgroup_ns_alloc_tls() as is. Introduce lttng_ust_cgroup_init_thread() which would call (void)get_cgroup_ns(). Likewise for all other contexts. Thoughts ? Thanks, Mathieu > > Signed-off-by: Norbert Lange <nolang...@gmail.com> > --- > * see > https://lore.kernel.org/all/CADYdroN3=pae66crtsvt9ahe4t+bt61-tvhfkcuwzykhhuy...@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 +++- > 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 | 16 +++++++------- > src/lib/lttng-ust/lttng-ust-comm.c | 24 ++++++++++----------- > src/lib/lttng-ust/lttng-ust-statedump.c | 2 +- > 12 files changed, 46 insertions(+), 32 deletions(-) > > diff --git a/src/lib/lttng-ust/lttng-context-cgroup-ns.c > b/src/lib/lttng-ust/lttng-context-cgroup-ns.c > index 34523ea1..3eb5ab5b 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_cgroup_ns_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_cgroup_ns))); > + if (init) > + (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..b68b939f 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_ipc_ns_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_ipc_ns))); > + if (init) > + (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..93e574ad 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_net_ns_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_net_ns))); > + if (init) > + (void)get_net_ns(); > } > diff --git a/src/lib/lttng-ust/lttng-context-procname.c > b/src/lib/lttng-ust/lttng-context-procname.c > index b5bf77be..95f6fe42 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_procname_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_procname)[0])); > + if (init) > + (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..ba24aad7 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_alloc_tls(false); > > /* 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_alloc_tls(false); > > 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..a957409b 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_time_ns_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_time_ns))); > + if (init) > + (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..0c802188 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_uts_ns_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_uts_ns))); > + if (init) > + (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..d3c9863e 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_vtid_alloc_tls(bool init) > { > asm volatile ("" : : "m" (URCU_TLS(cached_vtid))); > + if (init) > + (void)wrapper_getvtid(); > } > diff --git a/src/lib/lttng-ust/lttng-probes.c > b/src/lib/lttng-ust/lttng-probes.c > index e8e08ff1..314cb7a0 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_alloc_tls(false); > > /* > * 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_alloc_tls(false); > > 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..dbb3bd9f 100644 > --- a/src/lib/lttng-ust/lttng-tracer-core.h > +++ b/src/lib/lttng-ust/lttng-tracer-core.h > @@ -34,28 +34,28 @@ void ust_lock_nocheck(void) > void ust_unlock(void) > __attribute__((visibility("hidden"))); > > -void lttng_ust_alloc_tls(void) > +void lttng_ust_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_vtid_alloc_tls(void) > +void lttng_vtid_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_procname_alloc_tls(void) > +void lttng_procname_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_cgroup_ns_alloc_tls(void) > +void lttng_cgroup_ns_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_ipc_ns_alloc_tls(void) > +void lttng_ipc_ns_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_net_ns_alloc_tls(void) > +void lttng_net_ns_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_time_ns_alloc_tls(void) > +void lttng_time_ns_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > -void lttng_uts_ns_alloc_tls(void) > +void lttng_uts_ns_alloc_tls(bool init) > __attribute__((visibility("hidden"))); > > const char *lttng_ust_obj_get_name(int id) > diff --git a/src/lib/lttng-ust/lttng-ust-comm.c > b/src/lib/lttng-ust/lttng-ust-comm.c > index 7f34efe7..ba0bd985 100644 > --- a/src/lib/lttng-ust/lttng-ust-comm.c > +++ b/src/lib/lttng-ust/lttng-ust-comm.c > @@ -407,21 +407,21 @@ void lttng_lttng_ust_urcu_alloc_tls(void) > (void) lttng_ust_urcu_read_ongoing(); > } > > -void lttng_ust_alloc_tls(void) > +void lttng_ust_alloc_tls(bool init) > { > lttng_lttng_ust_urcu_alloc_tls(); > lttng_ringbuffer_alloc_tls(); > - lttng_vtid_alloc_tls(); > + lttng_vtid_alloc_tls(init); > lttng_nest_count_alloc_tls(); > - lttng_procname_alloc_tls(); > + lttng_procname_alloc_tls(init); > lttng_ust_mutex_nest_alloc_tls(); > lttng_ust_perf_counter_alloc_tls(); > 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_cgroup_ns_alloc_tls(init); > + lttng_ipc_ns_alloc_tls(init); > + lttng_net_ns_alloc_tls(init); > + lttng_time_ns_alloc_tls(init); > + lttng_uts_ns_alloc_tls(init); > 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_alloc_tls(true); > } > > 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_alloc_tls(false); > /* > * 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_alloc_tls(false); > > 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_alloc_tls(false); > > 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..ee180a0d 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_alloc_tls(false); > > data.exec_found = 0; > data.first = true; > -- > 2.35.1 > > _______________________________________________ > lttng-dev mailing list > lttng-dev@lists.lttng.org > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
