* [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
@ 2012-05-21 6:57 Srivatsa S. Bhat
2012-05-21 21:55 ` Rafael J. Wysocki
2012-06-16 14:00 ` Rafael J. Wysocki
0 siblings, 2 replies; 6+ messages in thread
From: Srivatsa S. Bhat @ 2012-05-21 6:57 UTC (permalink / raw)
To: rostedt, rjw; +Cc: mingo, lenb, pavel, linux-pm, linux-kernel, srivatsa.bhat
If function tracing is enabled for some of the low-level suspend/resume
functions, it leads to triple fault during resume from suspend, ultimately
ending up in a reboot instead of a resume (or a total refusal to come out
of suspended state, on some machines).
This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
disable tracing for suspend to ram). However, the changes made by that commit
got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
suspend/resume & hibernation code again). So, unfortunately since things are
not yet robust enough to allow tracing of low-level suspend/resume functions,
suspend/resume is still broken when ftrace is enabled.
So fix this by disabling function tracing during suspend/resume & hibernation.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
---
kernel/power/hibernate.c | 6 ++++++
kernel/power/suspend.c | 3 +++
2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index e09dfbf..52a1817 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
}
suspend_console();
+ ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend(PMSG_FREEZE);
@@ -377,6 +378,7 @@ int hibernation_snapshot(int platform_mode)
if (error || !in_suspend)
pm_restore_gfp_mask();
+ ftrace_start();
resume_console();
dpm_complete(msg);
@@ -479,6 +481,7 @@ int hibernation_restore(int platform_mode)
pm_prepare_console();
suspend_console();
+ ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
@@ -486,6 +489,7 @@ int hibernation_restore(int platform_mode)
dpm_resume_end(PMSG_RECOVER);
}
pm_restore_gfp_mask();
+ ftrace_start();
resume_console();
pm_restore_console();
return error;
@@ -512,6 +516,7 @@ int hibernation_platform_enter(void)
entering_platform_hibernation = true;
suspend_console();
+ ftrace_stop();
error = dpm_suspend_start(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -555,6 +560,7 @@ int hibernation_platform_enter(void)
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
+ ftrace_start();
resume_console();
Close:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 396d262..c8b7446 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -24,6 +24,7 @@
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
+#include <linux/ftrace.h>
#include <trace/events/power.h>
#include "power.h"
@@ -212,6 +213,7 @@ int suspend_devices_and_enter(suspend_state_t state)
goto Close;
}
suspend_console();
+ ftrace_stop();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
@@ -231,6 +233,7 @@ int suspend_devices_and_enter(suspend_state_t state)
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
+ ftrace_start();
resume_console();
Close:
if (suspend_ops->end)
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
2012-05-21 6:57 [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again Srivatsa S. Bhat
@ 2012-05-21 21:55 ` Rafael J. Wysocki
2012-05-21 22:16 ` Steven Rostedt
2012-06-16 14:00 ` Rafael J. Wysocki
1 sibling, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2012-05-21 21:55 UTC (permalink / raw)
To: Srivatsa S. Bhat, rostedt; +Cc: mingo, lenb, pavel, linux-pm, linux-kernel
On Monday, May 21, 2012, Srivatsa S. Bhat wrote:
> If function tracing is enabled for some of the low-level suspend/resume
> functions, it leads to triple fault during resume from suspend, ultimately
> ending up in a reboot instead of a resume (or a total refusal to come out
> of suspended state, on some machines).
>
> This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
> disable tracing for suspend to ram). However, the changes made by that commit
> got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
> suspend/resume & hibernation code again). So, unfortunately since things are
> not yet robust enough to allow tracing of low-level suspend/resume functions,
> suspend/resume is still broken when ftrace is enabled.
>
> So fix this by disabling function tracing during suspend/resume & hibernation.
Steve, any comments?
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> Cc: stable@vger.kernel.org
> ---
>
> kernel/power/hibernate.c | 6 ++++++
> kernel/power/suspend.c | 3 +++
> 2 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index e09dfbf..52a1817 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
> }
>
> suspend_console();
> + ftrace_stop();
> pm_restrict_gfp_mask();
>
> error = dpm_suspend(PMSG_FREEZE);
> @@ -377,6 +378,7 @@ int hibernation_snapshot(int platform_mode)
> if (error || !in_suspend)
> pm_restore_gfp_mask();
>
> + ftrace_start();
> resume_console();
> dpm_complete(msg);
>
> @@ -479,6 +481,7 @@ int hibernation_restore(int platform_mode)
>
> pm_prepare_console();
> suspend_console();
> + ftrace_stop();
> pm_restrict_gfp_mask();
> error = dpm_suspend_start(PMSG_QUIESCE);
> if (!error) {
> @@ -486,6 +489,7 @@ int hibernation_restore(int platform_mode)
> dpm_resume_end(PMSG_RECOVER);
> }
> pm_restore_gfp_mask();
> + ftrace_start();
> resume_console();
> pm_restore_console();
> return error;
> @@ -512,6 +516,7 @@ int hibernation_platform_enter(void)
>
> entering_platform_hibernation = true;
> suspend_console();
> + ftrace_stop();
> error = dpm_suspend_start(PMSG_HIBERNATE);
> if (error) {
> if (hibernation_ops->recover)
> @@ -555,6 +560,7 @@ int hibernation_platform_enter(void)
> Resume_devices:
> entering_platform_hibernation = false;
> dpm_resume_end(PMSG_RESTORE);
> + ftrace_start();
> resume_console();
>
> Close:
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index 396d262..c8b7446 100644
> --- a/kernel/power/suspend.c
> +++ b/kernel/power/suspend.c
> @@ -24,6 +24,7 @@
> #include <linux/export.h>
> #include <linux/suspend.h>
> #include <linux/syscore_ops.h>
> +#include <linux/ftrace.h>
> #include <trace/events/power.h>
>
> #include "power.h"
> @@ -212,6 +213,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> goto Close;
> }
> suspend_console();
> + ftrace_stop();
> suspend_test_start();
> error = dpm_suspend_start(PMSG_SUSPEND);
> if (error) {
> @@ -231,6 +233,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> suspend_test_start();
> dpm_resume_end(PMSG_RESUME);
> suspend_test_finish("resume devices");
> + ftrace_start();
> resume_console();
> Close:
> if (suspend_ops->end)
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
2012-05-21 21:55 ` Rafael J. Wysocki
@ 2012-05-21 22:16 ` Steven Rostedt
2012-05-22 6:12 ` Srivatsa S. Bhat
0 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2012-05-21 22:16 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Srivatsa S. Bhat, mingo, lenb, pavel, linux-pm, linux-kernel
On Mon, 2012-05-21 at 23:55 +0200, Rafael J. Wysocki wrote:
> On Monday, May 21, 2012, Srivatsa S. Bhat wrote:
> > If function tracing is enabled for some of the low-level suspend/resume
> > functions, it leads to triple fault during resume from suspend, ultimately
> > ending up in a reboot instead of a resume (or a total refusal to come out
> > of suspended state, on some machines).
> >
> > This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
> > disable tracing for suspend to ram). However, the changes made by that commit
> > got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
> > suspend/resume & hibernation code again). So, unfortunately since things are
> > not yet robust enough to allow tracing of low-level suspend/resume functions,
> > suspend/resume is still broken when ftrace is enabled.
> >
> > So fix this by disabling function tracing during suspend/resume & hibernation.
>
> Steve, any comments?
I was actually the one to recommend this solution ;-)
But that said, I actually do have some.
>
> > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> > Cc: stable@vger.kernel.org
> > ---
> >
> > kernel/power/hibernate.c | 6 ++++++
> > kernel/power/suspend.c | 3 +++
> > 2 files changed, 9 insertions(+), 0 deletions(-)
> >
> > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> > index e09dfbf..52a1817 100644
> > --- a/kernel/power/hibernate.c
> > +++ b/kernel/power/hibernate.c
> > @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
> > }
> >
> > suspend_console();
> > + ftrace_stop();
Is this a point of no return?
This probably isn't a problem, but I'm being a little paranoid. As
ftrace_stop/start() is just an on off switch, anyplace that calls
ftrace_start() will enable function tracing again. Ftrace_start() is
called by tracing_start() which is called when
the /sys/kernel/debug/tracing/trace file is opened and then closed. If
the close happens while the suspend is starting, it possibly can start
function tracing again.
But this race would have to be done by the user, which should have full
control as they are in the process of suspending the machine. But they
may do it by accident.
Hmm, actually, I don't even think the ftrace_stop() is needed by
tracing_stop() anymore. I should just nuke it.
-- Steve
> > pm_restrict_gfp_mask();
> >
> > error = dpm_suspend(PMSG_FREEZE);
> > @@ -377,6 +378,7 @@ int hibernation_snapshot(int platform_mode)
> > if (error || !in_suspend)
> > pm_restore_gfp_mask();
> >
> > + ftrace_start();
> > resume_console();
> > dpm_complete(msg);
> >
> > @@ -479,6 +481,7 @@ int hibernation_restore(int platform_mode)
> >
> > pm_prepare_console();
> > suspend_console();
> > + ftrace_stop();
> > pm_restrict_gfp_mask();
> > error = dpm_suspend_start(PMSG_QUIESCE);
> > if (!error) {
> > @@ -486,6 +489,7 @@ int hibernation_restore(int platform_mode)
> > dpm_resume_end(PMSG_RECOVER);
> > }
> > pm_restore_gfp_mask();
> > + ftrace_start();
> > resume_console();
> > pm_restore_console();
> > return error;
> > @@ -512,6 +516,7 @@ int hibernation_platform_enter(void)
> >
> > entering_platform_hibernation = true;
> > suspend_console();
> > + ftrace_stop();
> > error = dpm_suspend_start(PMSG_HIBERNATE);
> > if (error) {
> > if (hibernation_ops->recover)
> > @@ -555,6 +560,7 @@ int hibernation_platform_enter(void)
> > Resume_devices:
> > entering_platform_hibernation = false;
> > dpm_resume_end(PMSG_RESTORE);
> > + ftrace_start();
> > resume_console();
> >
> > Close:
> > diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> > index 396d262..c8b7446 100644
> > --- a/kernel/power/suspend.c
> > +++ b/kernel/power/suspend.c
> > @@ -24,6 +24,7 @@
> > #include <linux/export.h>
> > #include <linux/suspend.h>
> > #include <linux/syscore_ops.h>
> > +#include <linux/ftrace.h>
> > #include <trace/events/power.h>
> >
> > #include "power.h"
> > @@ -212,6 +213,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> > goto Close;
> > }
> > suspend_console();
> > + ftrace_stop();
> > suspend_test_start();
> > error = dpm_suspend_start(PMSG_SUSPEND);
> > if (error) {
> > @@ -231,6 +233,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> > suspend_test_start();
> > dpm_resume_end(PMSG_RESUME);
> > suspend_test_finish("resume devices");
> > + ftrace_start();
> > resume_console();
> > Close:
> > if (suspend_ops->end)
> >
> >
> >
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
2012-05-21 22:16 ` Steven Rostedt
@ 2012-05-22 6:12 ` Srivatsa S. Bhat
2012-05-29 11:54 ` Srivatsa S. Bhat
0 siblings, 1 reply; 6+ messages in thread
From: Srivatsa S. Bhat @ 2012-05-22 6:12 UTC (permalink / raw)
To: Steven Rostedt
Cc: Rafael J. Wysocki, mingo, lenb, pavel, linux-pm, linux-kernel
On 05/22/2012 03:46 AM, Steven Rostedt wrote:
> On Mon, 2012-05-21 at 23:55 +0200, Rafael J. Wysocki wrote:
>> On Monday, May 21, 2012, Srivatsa S. Bhat wrote:
>>> If function tracing is enabled for some of the low-level suspend/resume
>>> functions, it leads to triple fault during resume from suspend, ultimately
>>> ending up in a reboot instead of a resume (or a total refusal to come out
>>> of suspended state, on some machines).
>>>
>>> This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
>>> disable tracing for suspend to ram). However, the changes made by that commit
>>> got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
>>> suspend/resume & hibernation code again). So, unfortunately since things are
>>> not yet robust enough to allow tracing of low-level suspend/resume functions,
>>> suspend/resume is still broken when ftrace is enabled.
>>>
>>> So fix this by disabling function tracing during suspend/resume & hibernation.
>>
>> Steve, any comments?
>
> I was actually the one to recommend this solution ;-)
>
And I am grateful to you for that :-)
> But that said, I actually do have some.
>
>>
>>> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
>>> Cc: stable@vger.kernel.org
>>> ---
>>>
>>> kernel/power/hibernate.c | 6 ++++++
>>> kernel/power/suspend.c | 3 +++
>>> 2 files changed, 9 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
>>> index e09dfbf..52a1817 100644
>>> --- a/kernel/power/hibernate.c
>>> +++ b/kernel/power/hibernate.c
>>> @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
>>> }
>>>
>>> suspend_console();
>>> + ftrace_stop();
>
>
> Is this a point of no return?
>
Yes, especially as far as userspace is concerned.
> This probably isn't a problem, but I'm being a little paranoid. As
> ftrace_stop/start() is just an on off switch, anyplace that calls
> ftrace_start() will enable function tracing again. Ftrace_start() is
> called by tracing_start() which is called when
> the /sys/kernel/debug/tracing/trace file is opened and then closed. If
> the close happens while the suspend is starting, it possibly can start
> function tracing again.
>
> But this race would have to be done by the user, which should have full
> control as they are in the process of suspending the machine. But they
> may do it by accident.
>
Luckily, at all these places, all the userspace processes (and the freezable
kernel threads) are already frozen. So nobody will be running at this point
to open/close the trace file.
So there is no problem right?
(Of course, the non-freezable kernel threads might be running at this point,
but IIUC, they can't trigger ftrace_start() from some other internal path..)
Regards,
Srivatsa S. Bhat
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
2012-05-22 6:12 ` Srivatsa S. Bhat
@ 2012-05-29 11:54 ` Srivatsa S. Bhat
0 siblings, 0 replies; 6+ messages in thread
From: Srivatsa S. Bhat @ 2012-05-29 11:54 UTC (permalink / raw)
To: Steven Rostedt
Cc: Rafael J. Wysocki, mingo, lenb, pavel, linux-pm, linux-kernel
On 05/22/2012 11:42 AM, Srivatsa S. Bhat wrote:
> On 05/22/2012 03:46 AM, Steven Rostedt wrote:
>
>> On Mon, 2012-05-21 at 23:55 +0200, Rafael J. Wysocki wrote:
>>> On Monday, May 21, 2012, Srivatsa S. Bhat wrote:
>>>> If function tracing is enabled for some of the low-level suspend/resume
>>>> functions, it leads to triple fault during resume from suspend, ultimately
>>>> ending up in a reboot instead of a resume (or a total refusal to come out
>>>> of suspended state, on some machines).
>>>>
>>>> This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
>>>> disable tracing for suspend to ram). However, the changes made by that commit
>>>> got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
>>>> suspend/resume & hibernation code again). So, unfortunately since things are
>>>> not yet robust enough to allow tracing of low-level suspend/resume functions,
>>>> suspend/resume is still broken when ftrace is enabled.
>>>>
>>>> So fix this by disabling function tracing during suspend/resume & hibernation.
>>>
>>> Steve, any comments?
>>
>> I was actually the one to recommend this solution ;-)
>>
>
>
> And I am grateful to you for that :-)
>
>> But that said, I actually do have some.
>>
>>>
>>>> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
>>>> Cc: stable@vger.kernel.org
>>>> ---
>>>>
>>>> kernel/power/hibernate.c | 6 ++++++
>>>> kernel/power/suspend.c | 3 +++
>>>> 2 files changed, 9 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
>>>> index e09dfbf..52a1817 100644
>>>> --- a/kernel/power/hibernate.c
>>>> +++ b/kernel/power/hibernate.c
>>>> @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
>>>> }
>>>>
>>>> suspend_console();
>>>> + ftrace_stop();
>>
>>
>> Is this a point of no return?
>>
>
> Yes, especially as far as userspace is concerned.
>
>> This probably isn't a problem, but I'm being a little paranoid. As
>> ftrace_stop/start() is just an on off switch, anyplace that calls
>> ftrace_start() will enable function tracing again. Ftrace_start() is
>> called by tracing_start() which is called when
>> the /sys/kernel/debug/tracing/trace file is opened and then closed. If
>> the close happens while the suspend is starting, it possibly can start
>> function tracing again.
>>
>> But this race would have to be done by the user, which should have full
>> control as they are in the process of suspending the machine. But they
>> may do it by accident.
>>
>
>
> Luckily, at all these places, all the userspace processes (and the freezable
> kernel threads) are already frozen. So nobody will be running at this point
> to open/close the trace file.
>
> So there is no problem right?
>
> (Of course, the non-freezable kernel threads might be running at this point,
> but IIUC, they can't trigger ftrace_start() from some other internal path..)
>
Steve, do you have any other concerns about this patch or is it fine?
(I addressed your concern about some other event leading to ftrace_start() above).
Regards,
Srivatsa S. Bhat
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again
2012-05-21 6:57 [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again Srivatsa S. Bhat
2012-05-21 21:55 ` Rafael J. Wysocki
@ 2012-06-16 14:00 ` Rafael J. Wysocki
1 sibling, 0 replies; 6+ messages in thread
From: Rafael J. Wysocki @ 2012-06-16 14:00 UTC (permalink / raw)
To: Srivatsa S. Bhat; +Cc: rostedt, mingo, lenb, pavel, linux-pm, linux-kernel
On Monday, May 21, 2012, Srivatsa S. Bhat wrote:
> If function tracing is enabled for some of the low-level suspend/resume
> functions, it leads to triple fault during resume from suspend, ultimately
> ending up in a reboot instead of a resume (or a total refusal to come out
> of suspended state, on some machines).
>
> This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
> disable tracing for suspend to ram). However, the changes made by that commit
> got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
> suspend/resume & hibernation code again). So, unfortunately since things are
> not yet robust enough to allow tracing of low-level suspend/resume functions,
> suspend/resume is still broken when ftrace is enabled.
>
> So fix this by disabling function tracing during suspend/resume & hibernation.
>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> Cc: stable@vger.kernel.org
Queued up for 3.6 in linux-pm/linux-next.
Thanks,
Rafael
> ---
>
> kernel/power/hibernate.c | 6 ++++++
> kernel/power/suspend.c | 3 +++
> 2 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index e09dfbf..52a1817 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode)
> }
>
> suspend_console();
> + ftrace_stop();
> pm_restrict_gfp_mask();
>
> error = dpm_suspend(PMSG_FREEZE);
> @@ -377,6 +378,7 @@ int hibernation_snapshot(int platform_mode)
> if (error || !in_suspend)
> pm_restore_gfp_mask();
>
> + ftrace_start();
> resume_console();
> dpm_complete(msg);
>
> @@ -479,6 +481,7 @@ int hibernation_restore(int platform_mode)
>
> pm_prepare_console();
> suspend_console();
> + ftrace_stop();
> pm_restrict_gfp_mask();
> error = dpm_suspend_start(PMSG_QUIESCE);
> if (!error) {
> @@ -486,6 +489,7 @@ int hibernation_restore(int platform_mode)
> dpm_resume_end(PMSG_RECOVER);
> }
> pm_restore_gfp_mask();
> + ftrace_start();
> resume_console();
> pm_restore_console();
> return error;
> @@ -512,6 +516,7 @@ int hibernation_platform_enter(void)
>
> entering_platform_hibernation = true;
> suspend_console();
> + ftrace_stop();
> error = dpm_suspend_start(PMSG_HIBERNATE);
> if (error) {
> if (hibernation_ops->recover)
> @@ -555,6 +560,7 @@ int hibernation_platform_enter(void)
> Resume_devices:
> entering_platform_hibernation = false;
> dpm_resume_end(PMSG_RESTORE);
> + ftrace_start();
> resume_console();
>
> Close:
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index 396d262..c8b7446 100644
> --- a/kernel/power/suspend.c
> +++ b/kernel/power/suspend.c
> @@ -24,6 +24,7 @@
> #include <linux/export.h>
> #include <linux/suspend.h>
> #include <linux/syscore_ops.h>
> +#include <linux/ftrace.h>
> #include <trace/events/power.h>
>
> #include "power.h"
> @@ -212,6 +213,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> goto Close;
> }
> suspend_console();
> + ftrace_stop();
> suspend_test_start();
> error = dpm_suspend_start(PMSG_SUSPEND);
> if (error) {
> @@ -231,6 +233,7 @@ int suspend_devices_and_enter(suspend_state_t state)
> suspend_test_start();
> dpm_resume_end(PMSG_RESUME);
> suspend_test_finish("resume devices");
> + ftrace_start();
> resume_console();
> Close:
> if (suspend_ops->end)
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-06-16 13:55 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-05-21 6:57 [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again Srivatsa S. Bhat
2012-05-21 21:55 ` Rafael J. Wysocki
2012-05-21 22:16 ` Steven Rostedt
2012-05-22 6:12 ` Srivatsa S. Bhat
2012-05-29 11:54 ` Srivatsa S. Bhat
2012-06-16 14:00 ` Rafael J. Wysocki
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