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authorLinus Torvalds <torvalds@linux-foundation.org>2010-03-26 15:08:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-26 15:08:31 -0700
commit8128f55a0bc60cf3779135a1f837c4323e77c582 (patch)
treea6f23d18496049651617f5c5cbe21648fa521f4e /kernel
parent50da56706b989b99edb20f9c03172df193240c78 (diff)
parentc26f91a3df1999ec1b3298372d73f90cbab81106 (diff)
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Remove excessive early_res debug output softlockup: Stop spurious softlockup messages due to overflow rcu: Fix local_irq_disable() CONFIG_PROVE_RCU=y false positives rcu: Fix tracepoints & lockdep false positive rcu: Make rcu_read_lock_bh_held() allow for disabled BH
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcupdate.c23
-rw-r--r--kernel/softlockup.c4
2 files changed, 25 insertions, 2 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index f1125c1a632..63fe2543398 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -45,6 +45,7 @@
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/kernel_stat.h>
+#include <linux/hardirq.h>
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key rcu_lock_key;
@@ -66,6 +67,28 @@ EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
int rcu_scheduler_active __read_mostly;
EXPORT_SYMBOL_GPL(rcu_scheduler_active);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+/**
+ * rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?
+ *
+ * Check for bottom half being disabled, which covers both the
+ * CONFIG_PROVE_RCU and not cases. Note that if someone uses
+ * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
+ * will show the situation.
+ *
+ * Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
+ */
+int rcu_read_lock_bh_held(void)
+{
+ if (!debug_lockdep_rcu_enabled())
+ return 1;
+ return in_softirq();
+}
+EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
/*
* This function is invoked towards the end of the scheduler's initialization
* process. Before this is called, the idle task might contain
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 0d4c7898ab8..4b493f67dcb 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -155,11 +155,11 @@ void softlockup_tick(void)
* Wake up the high-prio watchdog task twice per
* threshold timespan.
*/
- if (now > touch_ts + softlockup_thresh/2)
+ if (time_after(now - softlockup_thresh/2, touch_ts))
wake_up_process(per_cpu(softlockup_watchdog, this_cpu));
/* Warn about unreasonable delays: */
- if (now <= (touch_ts + softlockup_thresh))
+ if (time_before_eq(now - softlockup_thresh, touch_ts))
return;
per_cpu(softlockup_print_ts, this_cpu) = touch_ts;