MINOR: thread: implement ha_thread_relax()
At some places we're using a painful ifdef to decide whether to use
sched_yield() or pl_cpu_relax() to relax in loops, this is hardly
exportable. Let's move this to ha_thread_relax() instead and une
this one only.
diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index a1a7fae..8067467 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -22,6 +22,11 @@
#ifndef _COMMON_HATHREADS_H
#define _COMMON_HATHREADS_H
+#include <unistd.h>
+#ifdef _POSIX_PRIORITY_SCHEDULING
+#include <sched.h>
+#endif
+
#include <common/config.h>
#include <common/initcall.h>
@@ -128,6 +133,13 @@
static inline void ha_set_tid(unsigned int tid)
{
+}
+
+static inline void ha_thread_relax(void)
+{
+#if _POSIX_PRIORITY_SCHEDULING
+ sched_yield();
+#endif
}
static inline void __ha_barrier_atomic_load(void)
@@ -391,6 +403,15 @@
tid_bit = (1UL << tid);
}
+static inline void ha_thread_relax(void)
+{
+#if _POSIX_PRIORITY_SCHEDULING
+ sched_yield();
+#else
+ pl_cpu_relax();
+#endif
+}
+
/* Marks the thread as harmless. Note: this must be true, i.e. the thread must
* not be touching any unprotected shared resource during this period. Usually
* this is called before poll(), but it may also be placed around very slow
diff --git a/src/hathreads.c b/src/hathreads.c
index 686edca..fc17318 100644
--- a/src/hathreads.c
+++ b/src/hathreads.c
@@ -52,11 +52,7 @@
{
_HA_ATOMIC_OR(&threads_harmless_mask, tid_bit);
while (threads_want_rdv_mask & all_threads_mask) {
-#if _POSIX_PRIORITY_SCHEDULING
- sched_yield();
-#else
- pl_cpu_relax();
-#endif
+ ha_thread_relax();
}
}
@@ -81,11 +77,7 @@
else if (_HA_ATOMIC_CAS(&threads_harmless_mask, &old, old & ~tid_bit))
break;
-#if _POSIX_PRIORITY_SCHEDULING
- sched_yield();
-#else
- pl_cpu_relax();
-#endif
+ ha_thread_relax();
}
/* one thread gets released at a time here, with its harmess bit off.
* The loss of this bit makes the other one continue to spin while the