Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull irq fixes and cleanups from Thomas Gleixner:
 "Commit e5ab012c3271 ("nohz: Make tick_nohz_irq_exit() irq safe") is
  the first commit in the series and the minimal necessary bugfix, which
  needs to go back into stable.

  The remanining commits enforce irq disabling in irq_exit(), sanitize
  the hardirq/softirq preempt count transition and remove a bunch of no
  longer necessary conditionals."

I personally love getting rid of the very subtle and confusing
IRQ_EXIT_OFFSET thing.  Even apart from the whole "more lines removed
than added" thing.

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irq: Don't re-enable interrupts at the end of irq_exit
  irq: Remove IRQ_EXIT_OFFSET workaround
  Revert "nohz: Make tick_nohz_irq_exit() irq safe"
  irq: Sanitize invoke_softirq
  irq: Ensure irq_exit() code runs with interrupts disabled
  nohz: Make tick_nohz_irq_exit() irq safe

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 29eb805ea4a6b2c98236bbd0f24cc00a45ec53df..c1d6555d2567468f86a6c1b6d745d927f1a25815 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -118,10 +118,8 @@
 
 #ifdef CONFIG_PREEMPT_COUNT
 # define preemptible() (preempt_count() == 0 && !irqs_disabled())
-# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
 #else
 # define preemptible() 0
-# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
 #endif
 
 #if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index b4d252fd195b927afd402977b64efb3faa7ed96f..14d7758074aadf4d1c43947ecef675e8bb6c044e 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -323,18 +323,10 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-       if (!force_irqthreads) {
-#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
+       if (!force_irqthreads)
                __do_softirq();
-#else
-               do_softirq();
-#endif
-       } else {
-               __local_bh_disable((unsigned long)__builtin_return_address(0),
-                               SOFTIRQ_OFFSET);
+       else
                wakeup_softirqd();
-               __local_bh_enable(SOFTIRQ_OFFSET);
-       }
 }
 
 /*
@@ -342,9 +334,15 @@ static inline void invoke_softirq(void)
  */
 void irq_exit(void)
 {
+#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED
+       local_irq_disable();
+#else
+       WARN_ON_ONCE(!irqs_disabled());
+#endif
+
        account_irq_exit_time(current);
        trace_hardirq_exit();
-       sub_preempt_count(IRQ_EXIT_OFFSET);
+       sub_preempt_count(HARDIRQ_OFFSET);
        if (!in_interrupt() && local_softirq_pending())
                invoke_softirq();
 
@@ -354,7 +352,6 @@ void irq_exit(void)
                tick_nohz_irq_exit();
 #endif
        rcu_irq_exit();
-       sched_preempt_enable_no_resched();
 }
 
 /*