Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

[karo-tx-linux.git] / kernel / softirq.c

diff --git a/kernel/softirq.c b/kernel/softirq.c
index f5cc25f147a646e210384d1cb98ae4a97240b3a7..b4d252fd195b927afd402977b64efb3faa7ed96f 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -195,21 +195,21 @@ void local_bh_enable_ip(unsigned long ip)
 EXPORT_SYMBOL(local_bh_enable_ip);
 
 /*
- * We restart softirq processing MAX_SOFTIRQ_RESTART times,
- * and we fall back to softirqd after that.
+ * We restart softirq processing for at most 2 ms,
+ * and if need_resched() is not set.
  *
- * This number has been established via experimentation.
+ * These limits have been established via experimentation.
  * The two things to balance is latency against fairness -
  * we want to handle softirqs as soon as possible, but they
  * should not be able to lock up the box.
  */
-#define MAX_SOFTIRQ_RESTART 10
+#define MAX_SOFTIRQ_TIME  msecs_to_jiffies(2)
 
 asmlinkage void __do_softirq(void)
 {
        struct softirq_action *h;
        __u32 pending;
-       int max_restart = MAX_SOFTIRQ_RESTART;
+       unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
        int cpu;
        unsigned long old_flags = current->flags;
 
@@ -264,11 +264,12 @@ restart:
        local_irq_disable();
 
        pending = local_softirq_pending();
-       if (pending && --max_restart)
-               goto restart;
+       if (pending) {
+               if (time_before(jiffies, end) && !need_resched())
+                       goto restart;
 
-       if (pending)
                wakeup_softirqd();
+       }
 
        lockdep_softirq_exit();