Fix: cache the result of getpid() internally

On Linux we called getpid() directly on each tracepoint and relied on
the glibc pid cache. However, in glibc 2.25, released on 2017-02-05, the
pid cache was removed which results in a getpid syscall on each event
when the vpid context is enabled.

Remove the Linux specific case and use our internal cache all the time.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
(cherry picked from commit 6d9b54d845b08d54d3f483f1130b499516588db3)

Change-Id: Ide9a7f3c99061e3b3d9f68cec86fc117dc684be7

diff --git a/liblttng-ust/lttng-context-vpid.c b/liblttng-ust/lttng-context-vpid.c
index 7d8091b..ab23011 100644 (file)
--- a/liblttng-ust/lttng-context-vpid.c
+++ b/liblttng-ust/lttng-context-vpid.c
@@ -26,17 +26,6 @@
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
 
-#ifdef __linux__
-static inline
-pid_t wrapper_getpid(void)
-{
-       return getpid();
-}
-
-void lttng_context_vpid_reset(void)
-{
-}
-#else
 /*
  * We cache the result to ensure we don't trigger a system call for
  * each event.
@@ -59,7 +48,6 @@ void lttng_context_vpid_reset(void)
 {
        cached_vpid = 0;
 }
-#endif
 
 static
 size_t vpid_get_size(struct lttng_ctx_field *field, size_t offset)