Ingo,
Please pull the latest tip/tracing/core tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/tracing/core
Steven Rostedt (1):
sched: do not account for NMIs
----
include/linux/hardirq.h | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
---------------------------
commit 2a7b8df04c11a70105c1abe67d006455d3bdc944
Author: Steven Rostedt <srostedt@xxxxxxxxxx>
Date: Thu Feb 12 14:16:46 2009 -0500
sched: do not account for NMIs
Impact: avoid corruption in system time accounting
Martin Schwidefsky told me that there was an issue with NMIs and
system accounting. The problem is that the accounting code is
not reentrant, and if an NMI goes off after an interrupt it can
corrupt the accounting.
For now, the best we can do is to treat NMIs like SMIs and they
are not accounted for.
This patch changes nmi_enter to not call __irq_enter and to do
the preempt-count and tracing calls directly.
Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 9841221..faa1cf8 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -175,24 +175,24 @@ extern void irq_enter(void);
*/
extern void irq_exit(void);
-#define nmi_enter() \
- do { \
- ftrace_nmi_enter(); \
- BUG_ON(in_nmi()); \
- add_preempt_count(NMI_OFFSET); \
- lockdep_off(); \
- rcu_nmi_enter(); \
- __irq_enter(); \
+#define nmi_enter() \
+ do { \
+ ftrace_nmi_enter(); \
+ BUG_ON(in_nmi()); \
+ add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
+ lockdep_off(); \
+ rcu_nmi_enter(); \
+ trace_hardirq_enter(); \
} while (0)
-#define nmi_exit() \
- do { \
- __irq_exit(); \
- rcu_nmi_exit(); \
- lockdep_on(); \
- BUG_ON(!in_nmi()); \
- sub_preempt_count(NMI_OFFSET); \
- ftrace_nmi_exit(); \
+#define nmi_exit() \
+ do { \
+ trace_hardirq_exit(); \
+ rcu_nmi_exit(); \
+ lockdep_on(); \
+ BUG_ON(!in_nmi()); \
+ sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
+ ftrace_nmi_exit(); \
} while (0)
#endif /* LINUX_HARDIRQ_H */
--
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