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-rw-r--r--kernel/posix-timers.c35
1 files changed, 33 insertions, 2 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 588c99da0307..329ce0172074 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -353,9 +353,40 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
* it should be restarted.
*/
if (timr->it.real.interval.tv64 != 0) {
+ ktime_t now = hrtimer_cb_get_time(timer);
+
+ /*
+ * FIXME: What we really want, is to stop this
+ * timer completely and restart it in case the
+ * SIG_IGN is removed. This is a non trivial
+ * change which involves sighand locking
+ * (sigh !), which we don't want to do late in
+ * the release cycle.
+ *
+ * For now we just let timers with an interval
+ * less than a jiffie expire every jiffie to
+ * avoid softirq starvation in case of SIG_IGN
+ * and a very small interval, which would put
+ * the timer right back on the softirq pending
+ * list. By moving now ahead of time we trick
+ * hrtimer_forward() to expire the timer
+ * later, while we still maintain the overrun
+ * accuracy, but have some inconsistency in
+ * the timer_gettime() case. This is at least
+ * better than a starved softirq. A more
+ * complex fix which solves also another related
+ * inconsistency is already in the pipeline.
+ */
+#ifdef CONFIG_HIGH_RES_TIMERS
+ {
+ ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
+
+ if (timr->it.real.interval.tv64 < kj.tv64)
+ now = ktime_add(now, kj);
+ }
+#endif
timr->it_overrun +=
- hrtimer_forward(timer,
- hrtimer_cb_get_time(timer),
+ hrtimer_forward(timer, now,
timr->it.real.interval);
ret = HRTIMER_RESTART;
++timr->it_requeue_pending;