From e00d3f52ccc6496a60992ac5a9d771b1d067eceb Mon Sep 17 00:00:00 2001
From: Haiqing Bai <Haiqing.Bai@windriver.com>
Date: Thu, 22 Nov 2018 08:42:48 +0000
Subject: [PATCH] Fixed 100% CPU using issue by adding minimum POSIX timer
 interval

Added minimum POSIX timer interval to prevent from timers firing
to quickly for the process to handle, resulting in 100% CPU and
endless signal queue.

Upstream-status: Backport
[From commit 1f0baae98a7b23e85f2bfd8f5de64795421c270e:
  - critical: added minimum POSIX timer interval to prevent from
    timers firing to quickly for the process to handle,
    resulting in 100% CPU and endless signal queue]

Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
---
 src/dep/eventtimer.h        | 3 ++-
 src/dep/eventtimer_itimer.c | 2 +-
 src/dep/eventtimer_posix.c  | 4 ++++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/dep/eventtimer.h b/src/dep/eventtimer.h
index 64e483a..0a21318 100644
--- a/src/dep/eventtimer.h
+++ b/src/dep/eventtimer.h
@@ -30,7 +30,8 @@
  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define EVENTTIMER_MAX_DESC           20
+#define EVENTTIMER_MAX_DESC		20
+#define EVENTTIMER_MIN_INTERVAL_US	250 /* 4000/sec */
 
 typedef struct EventTimer EventTimer;
 
diff --git a/src/dep/eventtimer_itimer.c b/src/dep/eventtimer_itimer.c
index cf3c6db..3bb7ec6 100644
--- a/src/dep/eventtimer_itimer.c
+++ b/src/dep/eventtimer_itimer.c
@@ -53,7 +53,7 @@
 
 #include "../ptpd.h"
 
-#define US_TIMER_INTERVAL (62500)
+#define US_TIMER_INTERVAL (31250)
 
 static volatile unsigned int elapsed;
 
diff --git a/src/dep/eventtimer_posix.c b/src/dep/eventtimer_posix.c
index 637eef3..f4a702d 100644
--- a/src/dep/eventtimer_posix.c
+++ b/src/dep/eventtimer_posix.c
@@ -100,6 +100,10 @@ eventTimerStart_posix(EventTimer *timer, double interval)
 	ts.tv_sec = interval;
 	ts.tv_nsec = (interval - ts.tv_sec) * 1E9;
 
+	if(!ts.tv_sec && ts.tv_nsec < EVENTTIMER_MIN_INTERVAL_US * 1000) {
+	    ts.tv_nsec = EVENTTIMER_MIN_INTERVAL_US * 1000;
+	}
+
 	DBGV("Timer %s start requested at %d.%4d sec interval\n", timer->id, ts.tv_sec, ts.tv_nsec);
 
 	its.it_interval = ts;
-- 
2.11.0

