* [git pull] sched: do not account for NMIs
@ 2009-02-12 19:29 Steven Rostedt
2009-02-13 10:03 ` Ingo Molnar
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2009-02-12 19:29 UTC (permalink / raw)
To: LKML, linux-arch
Cc: Ingo Molnar, Andrew Morton, Thomas Gleixner, Peter Zijlstra,
Frédéric Weisbecker, Martin Schwidefsky, wli,
Heiko Carstens
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@redhat.com>
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@redhat.com>
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 */
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [git pull] sched: do not account for NMIs
2009-02-12 19:29 [git pull] sched: do not account for NMIs Steven Rostedt
@ 2009-02-13 10:03 ` Ingo Molnar
2009-02-13 11:57 ` Ingo Molnar
0 siblings, 1 reply; 3+ messages in thread
From: Ingo Molnar @ 2009-02-13 10:03 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, linux-arch, Andrew Morton, Thomas Gleixner, Peter Zijlstra,
Frédéric Weisbecker, Martin Schwidefsky, wli,
Heiko Carstens
* Steven Rostedt <rostedt@goodmis.org> wrote:
> 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(-)
pulled into tip:tracing/ftrace, thanks Steve!
Btw., any progress on that ia64/etc. build failure related to the NMI
changes? This regression is blocking the linux-next and -mm exposure
of the latest ftrace changes.
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [git pull] sched: do not account for NMIs
2009-02-13 10:03 ` Ingo Molnar
@ 2009-02-13 11:57 ` Ingo Molnar
0 siblings, 0 replies; 3+ messages in thread
From: Ingo Molnar @ 2009-02-13 11:57 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, linux-arch, Andrew Morton, Thomas Gleixner, Peter Zijlstra,
Frédéric Weisbecker, Martin Schwidefsky, wli,
Heiko Carstens
* Ingo Molnar <mingo@elte.hu> wrote:
> Btw., any progress on that ia64/etc. build failure related to the
> NMI changes?
ah, disregard this - you already sent the fix for that.
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-02-12 19:29 [git pull] sched: do not account for NMIs Steven Rostedt
2009-02-13 10:03 ` Ingo Molnar
2009-02-13 11:57 ` Ingo Molnar
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