From 5793f93350dd8f29b7bc97eb1ad38873e4ecebde Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 16 Jan 2009 19:57:58 +0100
Subject: make use of PR_SET_TIMERSLACK

---
 src/daemon/main.c       |  2 ++
 src/pulsecore/rtclock.c | 26 ++++++++++++++++++++++++++
 src/pulsecore/rtclock.h |  1 +
 3 files changed, 29 insertions(+)

diff --git a/src/daemon/main.c b/src/daemon/main.c
index 08f65e6c..b01689f8 100644
--- a/src/daemon/main.c
+++ b/src/daemon/main.c
@@ -885,6 +885,8 @@ int main(int argc, char *argv[]) {
     else
         pa_log_info(_("Dude, your kernel stinks! The chef's recommendation today is Linux with high-resolution timers enabled!"));
 
+    pa_rtclock_hrtimer_enable();
+
 #ifdef SIGRTMIN
     /* Valgrind uses SIGRTMAX. To easy debugging we don't use it here */
     pa_rtsig_configure(SIGRTMIN, SIGRTMAX-1);
diff --git a/src/pulsecore/rtclock.c b/src/pulsecore/rtclock.c
index f33de830..5fc6da2b 100644
--- a/src/pulsecore/rtclock.c
+++ b/src/pulsecore/rtclock.c
@@ -27,9 +27,12 @@
 #include <stddef.h>
 #include <time.h>
 #include <sys/time.h>
+#include <sys/prctl.h>
+#include <errno.h>
 
 #include <pulse/timeval.h>
 #include <pulsecore/macro.h>
+#include <pulsecore/core-error.h>
 
 #include "rtclock.h"
 
@@ -89,6 +92,29 @@ pa_bool_t pa_rtclock_hrtimer(void) {
 #endif
 }
 
+void pa_rtclock_hrtimer_enable(void) {
+#ifdef PR_SET_TIMERSLACK
+    int slack_ns;
+
+    if ((slack_ns = prctl(PR_GET_TIMERSLACK, 0, 0, 0, 0)) < 0) {
+        pa_log_info("PR_GET_TIMERSLACK/PR_SET_TIMERSLACK not supported.");
+        return;
+    }
+
+    pa_log_debug("Timer slack set to %i us.", slack_ns/1000);
+
+    slack_ns = 500000000;
+
+    pa_log_debug("Setting timer slack to %i us.", slack_ns/1000);
+
+    if (prctl(PR_SET_TIMERSLACK, slack_ns, 0, 0, 0) < 0) {
+        pa_log_warn("PR_SET_TIMERSLACK failed: %s", pa_cstrerror(errno));
+        return;
+    }
+
+#endif
+}
+
 pa_usec_t pa_rtclock_usec(void) {
     struct timeval tv;
 
diff --git a/src/pulsecore/rtclock.h b/src/pulsecore/rtclock.h
index aa2cdace..281461df 100644
--- a/src/pulsecore/rtclock.h
+++ b/src/pulsecore/rtclock.h
@@ -35,6 +35,7 @@ pa_usec_t pa_rtclock_usec(void);
 
 pa_usec_t pa_rtclock_age(const struct timeval *tv);
 pa_bool_t pa_rtclock_hrtimer(void);
+void pa_rtclock_hrtimer_enable(void);
 
 /* timer with a resolution better than this are considered high-resolution */
 #define PA_HRTIMER_THRESHOLD_USEC 10
-- 
cgit