*/
#include <urcu/compiler.h>
+#include <urcu/system.h>
+#include <urcu/arch.h>
-#ifdef UST_VALGRIND
+void lttng_ust_getcpu_init(void);
+
+extern int (*lttng_get_cpu)(void);
+
+#ifdef LTTNG_UST_DEBUG_VALGRIND
/*
* Fallback on cpu 0 if liblttng-ust is build with Valgrind support.
* migration, so it is only statistically accurate.
*/
static inline
-int lttng_ust_get_cpu(void)
+int lttng_ust_get_cpu_internal(void)
{
return 0;
}
*/
#ifdef __linux__
-#ifdef __UCLIBC__
+/* old uClibc versions didn't have sched_getcpu */
+#if defined(__UCLIBC__) && __UCLIBC_MAJOR__ == 0 && \
+ (__UCLIBC_MINOR__ < 9 || \
+ (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ <= 32))
#include <sys/syscall.h>
#define __getcpu(cpu, node, cache) syscall(__NR_getcpu, cpu, node, cache)
/*
* If getcpu is not implemented in the kernel, use cpu 0 as fallback.
*/
static inline
-int lttng_ust_get_cpu(void)
+int lttng_ust_get_cpu_internal(void)
{
int cpu, ret;
* If getcpu is not implemented in the kernel, use cpu 0 as fallback.
*/
static inline
-int lttng_ust_get_cpu(void)
+int lttng_ust_get_cpu_internal(void)
{
int cpu;
}
#endif /* __UCLIBC__ */
-#elif defined(__FreeBSD__)
+#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
/*
- * FreeBSD does not allow query of CPU ID. Always use CPU number 0, with
- * the assocated performance degradation on SMP.
+ * FreeBSD and Cygwin do not allow query of CPU ID. Always use CPU
+ * number 0, with the assocated performance degradation on SMP.
*/
static inline
-int lttng_ust_get_cpu(void)
+int lttng_ust_get_cpu_internal(void)
{
return 0;
}
#endif
+static inline
+int lttng_ust_get_cpu(void)
+{
+ int (*getcpu)(void) = CMM_LOAD_SHARED(lttng_get_cpu);
+
+ if (caa_likely(!getcpu)) {
+ return lttng_ust_get_cpu_internal();
+ } else {
+ return getcpu();
+ }
+}
+
#endif /* _LTTNG_GETCPU_H */