[lttng-dev] [PATCH v2] Improve tracef/tracelog to use the stack for small strings
From: Norbert Lange
Support two common cases, one being that the resulting message is
small enough to fit into a on-stack buffer.
The seconds being the common 'printf("%s", "Message")' scheme.
Unfortunately, iterating a va_list is destructive,
so it has to be copied before calling vprintf.
The implementation was moved to a separate file,
used by both tracef.c and tracelog.c.
Signed-off-by: Norbert Lange
---
v2 -> v3:
* Wrap macro in do/while
* drop loop
* other changes in response to feedback
v2:
- move define into src/common/tracer.h
see https://lists.lttng.org/pipermail/lttng-dev/2021-May/029977.html
- moved macro magic into common tracelog-internal.h header
- rebased onto master
---
src/common/tracer.h | 2 +
src/lib/lttng-ust/tracef.c| 32 +++--
src/lib/lttng-ust/tracelog-internal.h | 95 +++
src/lib/lttng-ust/tracelog.c | 40 +++
4 files changed, 114 insertions(+), 55 deletions(-)
create mode 100644 src/lib/lttng-ust/tracelog-internal.h
diff --git a/src/common/tracer.h b/src/common/tracer.h
index 2affd6ab..8e18c9b5 100644
--- a/src/common/tracer.h
+++ b/src/common/tracer.h
@@ -26,6 +26,8 @@
#define LTTNG_RFLAG_EXTENDED RING_BUFFER_RFLAG_END
#define LTTNG_RFLAG_END(LTTNG_RFLAG_EXTENDED << 1)
+#define LTTNG_TRACE_PRINTF_BUFSIZE 512
+
/*
* LTTng client type enumeration. Used by the consumer to map the
* callbacks from its own address space.
diff --git a/src/lib/lttng-ust/tracef.c b/src/lib/lttng-ust/tracef.c
index c05c7811..92911e1d 100644
--- a/src/lib/lttng-ust/tracef.c
+++ b/src/lib/lttng-ust/tracef.c
@@ -7,6 +7,7 @@
#define _LGPL_SOURCE
#include
#include "common/macros.h"
+#include "common/tracer.h"
/* The tracepoint definition is public, but the provider definition is hidden.
*/
#define LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
@@ -15,39 +16,22 @@
#define LTTNG_UST_TRACEPOINT_DEFINE
#include "lttng-ust-tracef-provider.h"
-static inline
-void lttng_ust___vtracef(const char *fmt, va_list ap)
- __attribute__((always_inline, format(printf, 1, 0)));
-static inline
-void lttng_ust___vtracef(const char *fmt, va_list ap)
-{
- char *msg;
- const int len = vasprintf(&msg, fmt, ap);
-
- /* len does not include the final \0 */
- if (len < 0)
- goto end;
- lttng_ust_tracepoint_cb_lttng_ust_tracef___event(msg, len,
- LTTNG_UST_CALLER_IP());
- free(msg);
-end:
- return;
-}
+#include "tracelog-internal.h"
void lttng_ust__vtracef(const char *fmt, va_list ap)
__attribute__((format(printf, 1, 0)));
void lttng_ust__vtracef(const char *fmt, va_list ap)
{
- lttng_ust___vtracef(fmt, ap);
+ LTTNG_UST_TRACELOG_VALIST(fmt, ap,
+ lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
+ msg, len, LTTNG_UST_CALLER_IP());
}
void lttng_ust__tracef(const char *fmt, ...)
__attribute__((format(printf, 1, 2)));
void lttng_ust__tracef(const char *fmt, ...)
{
- va_list ap;
-
- va_start(ap, fmt);
- lttng_ust___vtracef(fmt, ap);
- va_end(ap);
+ LTTNG_UST_TRACELOG_VARARG(fmt,
+ lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
+ msg, len, LTTNG_UST_CALLER_IP());
}
diff --git a/src/lib/lttng-ust/tracelog-internal.h
b/src/lib/lttng-ust/tracelog-internal.h
new file mode 100644
index ..34537023
--- /dev/null
+++ b/src/lib/lttng-ust/tracelog-internal.h
@@ -0,0 +1,95 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2013-2014 Mathieu Desnoyers
+ * Copyright (C) 2021 Norbert Lange
+ *
+ * Shared helper macro for tracelog and tracef.
+ */
+
+#define LTTNG_UST_TRACELOG_VARARG(fmt, callback, ...) \
+ do { \
+ va_list ap; \
+ char local_buf[LTTNG_TRACE_PRINTF_BUFSIZE]; \
+ size_t len = 0; \
+ char *msg = local_buf; \
+ char *alloc_buff = NULL; \
+\
+ if (caa_unlikely(fmt[0] == '%' && fmt[1] == 's' && fmt[2] ==
'\0')) { \
+ va_start(ap, fmt); \
+ msg = va_arg(ap, char *); \
+ va_end(ap); \
+ len = strlen(msg); \
+ } else { \
+ int ret; \
+ size_t buflen = sizeof(local_buf); \
+\
+ /* On-stack buffer attempt */ \
+ va_start(ap, fmt); \
+ ret = vsnprintf(msg, buflen, fmt, ap); \
+ va_end(ap); \
+ if (caa_unlikely(ret < 0)) \
+ break; \
+ len = (size_t)ret; \
+\
+ if (caa_unlikely(len >= sizeof(local_buf))) { \
+ buflen = len + 1; \
+ alloc_buff = (char *)malloc(buflen); \
+
[lttng-dev] [PATCH v2 2/2] lttng_ust_init_thread: call urcu_register_thread
From: Norbert Lange Eagerly register the thread, and avoid taking mutex during the first tracepoint. Signed-off-by: Norbert Lange Acked-by: Mathieu Desnoyers --- src/lib/lttng-ust/lttng-ust-comm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c index 0a039fef..0fe2da46 100644 --- a/src/lib/lttng-ust/lttng-ust-comm.c +++ b/src/lib/lttng-ust/lttng-ust-comm.c @@ -447,6 +447,8 @@ void lttng_ust_init_thread(void) * this thread attempts to use them. */ lttng_ust_common_init_thread(LTTNG_UST_INIT_THREAD_MASK); + + lttng_ust_urcu_register_thread(); } int lttng_get_notify_socket(void *owner) -- 2.35.1 ___ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
[lttng-dev] [PATCH v2 1/2] lttng_ust_init_thread: initialise cached context values
From: Norbert Lange
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
---
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-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 ++-
.../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(-)
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_all
Re: [lttng-dev] [PATCH v2] Improve tracef/tracelog to use the stack for small strings
Am Mo., 1. Aug. 2022 um 16:35 Uhr schrieb Norbert Lange :
>
> From: Norbert Lange
>
> Support two common cases, one being that the resulting message is
> small enough to fit into a on-stack buffer.
> The seconds being the common 'printf("%s", "Message")' scheme.
>
> Unfortunately, iterating a va_list is destructive,
> so it has to be copied before calling vprintf.
>
> The implementation was moved to a separate file,
> used by both tracef.c and tracelog.c.
>
> Signed-off-by: Norbert Lange
> ---
> v2 -> v3:
>
> * Wrap macro in do/while
> * drop loop
> * other changes in response to feedback
>
> v2:
> - move define into src/common/tracer.h
> see https://lists.lttng.org/pipermail/lttng-dev/2021-May/029977.html
> - moved macro magic into common tracelog-internal.h header
> - rebased onto master
> ---
> src/common/tracer.h | 2 +
> src/lib/lttng-ust/tracef.c| 32 +++--
> src/lib/lttng-ust/tracelog-internal.h | 95 +++
> src/lib/lttng-ust/tracelog.c | 40 +++
> 4 files changed, 114 insertions(+), 55 deletions(-)
> create mode 100644 src/lib/lttng-ust/tracelog-internal.h
>
> diff --git a/src/common/tracer.h b/src/common/tracer.h
> index 2affd6ab..8e18c9b5 100644
> --- a/src/common/tracer.h
> +++ b/src/common/tracer.h
> @@ -26,6 +26,8 @@
> #define LTTNG_RFLAG_EXTENDED RING_BUFFER_RFLAG_END
> #define LTTNG_RFLAG_END(LTTNG_RFLAG_EXTENDED << 1)
>
> +#define LTTNG_TRACE_PRINTF_BUFSIZE 512
> +
> /*
> * LTTng client type enumeration. Used by the consumer to map the
> * callbacks from its own address space.
> diff --git a/src/lib/lttng-ust/tracef.c b/src/lib/lttng-ust/tracef.c
> index c05c7811..92911e1d 100644
> --- a/src/lib/lttng-ust/tracef.c
> +++ b/src/lib/lttng-ust/tracef.c
> @@ -7,6 +7,7 @@
> #define _LGPL_SOURCE
> #include
> #include "common/macros.h"
> +#include "common/tracer.h"
>
> /* The tracepoint definition is public, but the provider definition is
> hidden. */
> #define LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
> @@ -15,39 +16,22 @@
> #define LTTNG_UST_TRACEPOINT_DEFINE
> #include "lttng-ust-tracef-provider.h"
>
> -static inline
> -void lttng_ust___vtracef(const char *fmt, va_list ap)
> - __attribute__((always_inline, format(printf, 1, 0)));
> -static inline
> -void lttng_ust___vtracef(const char *fmt, va_list ap)
> -{
> - char *msg;
> - const int len = vasprintf(&msg, fmt, ap);
> -
> - /* len does not include the final \0 */
> - if (len < 0)
> - goto end;
> - lttng_ust_tracepoint_cb_lttng_ust_tracef___event(msg, len,
> - LTTNG_UST_CALLER_IP());
> - free(msg);
> -end:
> - return;
> -}
> +#include "tracelog-internal.h"
>
> void lttng_ust__vtracef(const char *fmt, va_list ap)
> __attribute__((format(printf, 1, 0)));
> void lttng_ust__vtracef(const char *fmt, va_list ap)
> {
> - lttng_ust___vtracef(fmt, ap);
> + LTTNG_UST_TRACELOG_VALIST(fmt, ap,
> + lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
> + msg, len, LTTNG_UST_CALLER_IP());
> }
>
> void lttng_ust__tracef(const char *fmt, ...)
> __attribute__((format(printf, 1, 2)));
> void lttng_ust__tracef(const char *fmt, ...)
> {
> - va_list ap;
> -
> - va_start(ap, fmt);
> - lttng_ust___vtracef(fmt, ap);
> - va_end(ap);
> + LTTNG_UST_TRACELOG_VARARG(fmt,
> + lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
> + msg, len, LTTNG_UST_CALLER_IP());
> }
> diff --git a/src/lib/lttng-ust/tracelog-internal.h
> b/src/lib/lttng-ust/tracelog-internal.h
> new file mode 100644
> index ..34537023
> --- /dev/null
> +++ b/src/lib/lttng-ust/tracelog-internal.h
> @@ -0,0 +1,95 @@
> +/*
> + * SPDX-License-Identifier: MIT
> + *
> + * Copyright (C) 2013-2014 Mathieu Desnoyers
> + * Copyright (C) 2021 Norbert Lange
> + *
> + * Shared helper macro for tracelog and tracef.
> + */
> +
> +#define LTTNG_UST_TRACELOG_VARARG(fmt, callback, ...) \
> + do { \
> + va_list ap; \
> + char local_buf[LTTNG_TRACE_PRINTF_BUFSIZE]; \
> + size_t len = 0; \
> + char *msg = local_buf; \
> + char *alloc_buff = NULL; \
> +\
> + if (caa_unlikely(fmt[0] == '%' && fmt[1] == 's' && fmt[2] ==
> '\0')) { \
> + va_start(ap, fmt); \
> + msg = va_arg(ap, char *); \
> + va_end(ap); \
> + len = strlen(msg); \
> + } else { \
> + int ret; \
> + size_t buflen = sizeof(local_buf); \
> +\
> + /* On-stack buffer attempt */ \
> + va_start(ap, fmt); \
> + ret = vsnprintf(msg, buflen, fmt, ap); \
> + va_end(ap); \
> + if (caa
Re: [lttng-dev] [PATCH v2 1/2] lttng_ust_init_thread: initialise cached context values
- On Aug 1, 2022, at 10:36 AM, Norbert Lange via lttng-dev
lttng-dev@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
--
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
Re: [lttng-dev] [PATCH v2] Improve tracef/tracelog to use the stack for small strings
- On Aug 1, 2022, at 10:35 AM, Norbert Lange via lttng-dev
lttng-dev@lists.lttng.org wrote:
> From: Norbert Lange
>
> Support two common cases, one being that the resulting message is
> small enough to fit into a on-stack buffer.
> The seconds being the common 'printf("%s", "Message")' scheme.
>
> Unfortunately, iterating a va_list is destructive,
> so it has to be copied before calling vprintf.
>
> The implementation was moved to a separate file,
> used by both tracef.c and tracelog.c.
>
> Signed-off-by: Norbert Lange
Merged, thanks!
Mathieu
> ---
> v2 -> v3:
>
> * Wrap macro in do/while
> * drop loop
> * other changes in response to feedback
>
> v2:
> - move define into src/common/tracer.h
>see https://lists.lttng.org/pipermail/lttng-dev/2021-May/029977.html
> - moved macro magic into common tracelog-internal.h header
> - rebased onto master
> ---
> src/common/tracer.h | 2 +
> src/lib/lttng-ust/tracef.c| 32 +++--
> src/lib/lttng-ust/tracelog-internal.h | 95 +++
> src/lib/lttng-ust/tracelog.c | 40 +++
> 4 files changed, 114 insertions(+), 55 deletions(-)
> create mode 100644 src/lib/lttng-ust/tracelog-internal.h
>
> diff --git a/src/common/tracer.h b/src/common/tracer.h
> index 2affd6ab..8e18c9b5 100644
> --- a/src/common/tracer.h
> +++ b/src/common/tracer.h
> @@ -26,6 +26,8 @@
> #define LTTNG_RFLAG_EXTENDED RING_BUFFER_RFLAG_END
> #define LTTNG_RFLAG_END (LTTNG_RFLAG_EXTENDED << 1)
>
> +#define LTTNG_TRACE_PRINTF_BUFSIZE 512
> +
> /*
> * LTTng client type enumeration. Used by the consumer to map the
> * callbacks from its own address space.
> diff --git a/src/lib/lttng-ust/tracef.c b/src/lib/lttng-ust/tracef.c
> index c05c7811..92911e1d 100644
> --- a/src/lib/lttng-ust/tracef.c
> +++ b/src/lib/lttng-ust/tracef.c
> @@ -7,6 +7,7 @@
> #define _LGPL_SOURCE
> #include
> #include "common/macros.h"
> +#include "common/tracer.h"
>
> /* The tracepoint definition is public, but the provider definition is hidden.
> */
> #define LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION
> @@ -15,39 +16,22 @@
> #define LTTNG_UST_TRACEPOINT_DEFINE
> #include "lttng-ust-tracef-provider.h"
>
> -static inline
> -void lttng_ust___vtracef(const char *fmt, va_list ap)
> - __attribute__((always_inline, format(printf, 1, 0)));
> -static inline
> -void lttng_ust___vtracef(const char *fmt, va_list ap)
> -{
> - char *msg;
> - const int len = vasprintf(&msg, fmt, ap);
> -
> - /* len does not include the final \0 */
> - if (len < 0)
> - goto end;
> - lttng_ust_tracepoint_cb_lttng_ust_tracef___event(msg, len,
> - LTTNG_UST_CALLER_IP());
> - free(msg);
> -end:
> - return;
> -}
> +#include "tracelog-internal.h"
>
> void lttng_ust__vtracef(const char *fmt, va_list ap)
> __attribute__((format(printf, 1, 0)));
> void lttng_ust__vtracef(const char *fmt, va_list ap)
> {
> - lttng_ust___vtracef(fmt, ap);
> + LTTNG_UST_TRACELOG_VALIST(fmt, ap,
> + lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
> + msg, len, LTTNG_UST_CALLER_IP());
> }
>
> void lttng_ust__tracef(const char *fmt, ...)
> __attribute__((format(printf, 1, 2)));
> void lttng_ust__tracef(const char *fmt, ...)
> {
> - va_list ap;
> -
> - va_start(ap, fmt);
> - lttng_ust___vtracef(fmt, ap);
> - va_end(ap);
> + LTTNG_UST_TRACELOG_VARARG(fmt,
> + lttng_ust_tracepoint_cb_lttng_ust_tracef___event,
> + msg, len, LTTNG_UST_CALLER_IP());
> }
> diff --git a/src/lib/lttng-ust/tracelog-internal.h
> b/src/lib/lttng-ust/tracelog-internal.h
> new file mode 100644
> index ..34537023
> --- /dev/null
> +++ b/src/lib/lttng-ust/tracelog-internal.h
> @@ -0,0 +1,95 @@
> +/*
> + * SPDX-License-Identifier: MIT
> + *
> + * Copyright (C) 2013-2014 Mathieu Desnoyers
> + * Copyright (C) 2021 Norbert Lange
> + *
> + * Shared helper macro for tracelog and tracef.
> + */
> +
> +#define LTTNG_UST_TRACELOG_VARARG(fmt, callback, ...) \
> + do { \
> + va_list ap; \
> + char local_buf[LTTNG_TRACE_PRINTF_BUFSIZE]; \
> + size_t len = 0; \
> + char *msg = local_buf; \
> + char *alloc_buff = NULL; \
> +\
> + if (caa_unlikely(fmt[0] == '%' && fmt[1] == 's' && fmt[2] ==
> '\0')) { \
> + va_start(ap, fmt); \
> + msg = va_arg(ap, char *); \
> + va_end(ap); \
> + len = strlen(msg); \
> + } else { \
> + int ret; \
> + size_t buflen = sizeof(local_buf); \
> +\
> + /* On-stack buffer attempt */ \
> + va_start(ap, fmt); \
> + ret = vsnprintf(msg, buflen, fmt, ap); \
> + va_end(ap); \
> + if (caa_unlikely(ret < 0)) \
> +
Re: [lttng-dev] [PATCH v2 2/2] lttng_ust_init_thread: call urcu_register_thread
- On Aug 1, 2022, at 10:37 AM, Norbert Lange nolang...@gmail.com wrote: > From: Norbert Lange > > Eagerly register the thread, and avoid taking mutex during the > first tracepoint. Merged, thanks! Mathieu > > Signed-off-by: Norbert Lange > Acked-by: Mathieu Desnoyers > --- > src/lib/lttng-ust/lttng-ust-comm.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/src/lib/lttng-ust/lttng-ust-comm.c > b/src/lib/lttng-ust/lttng-ust-comm.c > index 0a039fef..0fe2da46 100644 > --- a/src/lib/lttng-ust/lttng-ust-comm.c > +++ b/src/lib/lttng-ust/lttng-ust-comm.c > @@ -447,6 +447,8 @@ void lttng_ust_init_thread(void) >* this thread attempts to use them. >*/ > lttng_ust_common_init_thread(LTTNG_UST_INIT_THREAD_MASK); > + > + lttng_ust_urcu_register_thread(); > } > > int lttng_get_notify_socket(void *owner) > -- > 2.35.1 -- 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
Re: [lttng-dev] [PATCH v2] Improve tracef/tracelog to use the stack for small strings
- On Aug 1, 2022, at 10:44 AM, Norbert Lange via lttng-dev lttng-dev@lists.lttng.org wrote: [...] > > Any chance of not having to link liblttng-ust for the tracelog/tracef > functions, > like all other tracepoints (only hard dependency on liblttng-ust-tracepoint)? > My involvement is limited to "complain-only" for that one, but think of > how technically great that would be! Here is how we could do this: 1) move the implementation of src/lib/lttng-ust/tracelog.c to its own .so, e.g. liblttng-ust-tracelog.so, 2) modify the tracelog/tracef public headers so they dlopen() this new .so from a library constructor, similarly to what tracepoint.h does. We'd need to make sure the symbols from tracelog.c are still emitted in liblttng-ust.so, _and_ have another version (with a prefix/suffix) emitted from liblttng-ust-tracelog.so, so we don't break ABI. Thoughts ? Thanks, Mathieu -- 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
