Re: [PATCH lttng-modules] Fix: Remove not used PREEMPT_ACTIVE in Linux 4.4

Re: [PATCH lttng-modules] Fix: Remove not used PREEMPT_ACTIVE in Linux 4.4

[Mathieu Desnoyers]

Hi,

In instrumentation/events/lttng-module/sched.h, there are ifdefs
checking the kernel version against which lttng-modules is build.
Please ensure you don't remove this flag when building against
older kernels.

The mainline/sched.h file should be removed from lttng-modules,
it's a leftover of initial porting of instrumentation from the
kernel.

Thanks,

Mathieu

----- On Feb 2, 2016, at 7:56 AM, Felipe F. Tonello eu@felipetonello.com wrote:

> This flag was removed in Linux 4.4 as it is not necessary to use it any more.
> 
> Check Linux commits:
> e61bf1e43b6f ('sched/core: Kill PREEMPT_ACTIVE')
> da7142e2ed73 ('sched/core: Simplify preempt_count tests')
> 3d8f74dd4ca1 ('sched/core: Stop setting PREEMPT_ACTIVE')
> 
> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
> ---
> instrumentation/events/lttng-module/sched.h | 8 ++++----
> instrumentation/events/mainline/sched.h     | 2 +-
> 2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/instrumentation/events/lttng-module/sched.h
> b/instrumentation/events/lttng-module/sched.h
> index 4f3676bf54ea..53edd2af0e06 100644
> --- a/instrumentation/events/lttng-module/sched.h
> +++ b/instrumentation/events/lttng-module/sched.h
> @@ -51,7 +51,7 @@ static inline long __trace_sched_switch_state(struct
> task_struct *p)
> 	/*
> 	 * For all intents and purposes a preempted task is a running task.
> 	 */
> -	if (preempt_count() & PREEMPT_ACTIVE)
> +	if (preempt_count())
> 		state = TASK_RUNNING | TASK_STATE_MAX;
> #endif	/* CONFIG_PREEMPT */
> 
> @@ -68,7 +68,7 @@ static inline long __trace_sched_switch_state(struct
> task_struct *p)
> 	/*
> 	 * For all intents and purposes a preempted task is a running task.
> 	 */
> -	if (task_preempt_count(p) & PREEMPT_ACTIVE)
> +	if (task_preempt_count(p))
> 		state = TASK_RUNNING | TASK_STATE_MAX;
> #endif
> 
> @@ -85,7 +85,7 @@ static inline long __trace_sched_switch_state(struct
> task_struct *p)
> 	/*
> 	 * For all intents and purposes a preempted task is a running task.
> 	 */
> -	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
> +	if (task_thread_info(p)->preempt_count)
> 		state = TASK_RUNNING | TASK_STATE_MAX;
> #endif
> 
> @@ -102,7 +102,7 @@ static inline long __trace_sched_switch_state(struct
> task_struct *p)
> 	/*
> 	 * For all intents and purposes a preempted task is a running task.
> 	 */
> -	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
> +	if (task_thread_info(p)->preempt_count)
> 		state = TASK_RUNNING;
> #endif
> 
> diff --git a/instrumentation/events/mainline/sched.h
> b/instrumentation/events/mainline/sched.h
> index ea7a2035456d..790085190a4b 100644
> --- a/instrumentation/events/mainline/sched.h
> +++ b/instrumentation/events/mainline/sched.h
> @@ -100,7 +100,7 @@ static inline long __trace_sched_switch_state(struct
> task_struct *p)
> 	/*
> 	 * For all intents and purposes a preempted task is a running task.
> 	 */
> -	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
> +	if (task_thread_info(p)->preempt_count)
> 		state = TASK_RUNNING | TASK_STATE_MAX;
> #endif
> 
> --
> 2.7.0
> 
> 
> _______________________________________________
> lttng-dev mailing list
> lttng-dev@lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

Re: [PATCH lttng-modules] Fix: Remove not used PREEMPT_ACTIVE in Linux 4.4

[Felipe Tonello]

Hi Mathieu,

On Tue, Feb 2, 2016 at 1:38 PM, Mathieu Desnoyers
<mathieu.desnoyers@efficios.com> wrote:
> Hi,
>
> In instrumentation/events/lttng-module/sched.h, there are ifdefs
> checking the kernel version against which lttng-modules is build.
> Please ensure you don't remove this flag when building against
> older kernels.

Actually I just realized that this file is correct already.

>
> The mainline/sched.h file should be removed from lttng-modules,
> it's a leftover of initial porting of instrumentation from the
> kernel.

I will send another patch removing this file.

Felipe

Re: [PATCH lttng-modules] Fix: Remove not used PREEMPT_ACTIVE in Linux 4.4

[Mathieu Desnoyers]

----- On Feb 2, 2016, at 9:22 AM, Felipe F. Tonello eu@felipetonello.com wrote:

> Hi Mathieu,
> 
> On Tue, Feb 2, 2016 at 1:38 PM, Mathieu Desnoyers
> <mathieu.desnoyers@efficios.com> wrote:
>> Hi,
>>
>> In instrumentation/events/lttng-module/sched.h, there are ifdefs
>> checking the kernel version against which lttng-modules is build.
>> Please ensure you don't remove this flag when building against
>> older kernels.
> 
> Actually I just realized that this file is correct already.
> 
>>
>> The mainline/sched.h file should be removed from lttng-modules,
>> it's a leftover of initial porting of instrumentation from the
>> kernel.
> 
> I will send another patch removing this file.

We would need to edit the README file under instrumentation/events too.

Thanks,

Mathieu

> 
> Felipe

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

[PATCH lttng-modules] Fix: Remove not used PREEMPT_ACTIVE in Linux 4.4

[Felipe F. Tonello]

This flag was removed in Linux 4.4 as it is not necessary to use it any more.

Check Linux commits:
e61bf1e43b6f ('sched/core: Kill PREEMPT_ACTIVE')
da7142e2ed73 ('sched/core: Simplify preempt_count tests')
3d8f74dd4ca1 ('sched/core: Stop setting PREEMPT_ACTIVE')

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
---
 instrumentation/events/lttng-module/sched.h | 8 ++++----
 instrumentation/events/mainline/sched.h     | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/instrumentation/events/lttng-module/sched.h b/instrumentation/events/lttng-module/sched.h
index 4f3676bf54ea..53edd2af0e06 100644
--- a/instrumentation/events/lttng-module/sched.h
+++ b/instrumentation/events/lttng-module/sched.h
@@ -51,7 +51,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
 	/*
 	 * For all intents and purposes a preempted task is a running task.
 	 */
-	if (preempt_count() & PREEMPT_ACTIVE)
+	if (preempt_count())
 		state = TASK_RUNNING | TASK_STATE_MAX;
 #endif	/* CONFIG_PREEMPT */
 
@@ -68,7 +68,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
 	/*
 	 * For all intents and purposes a preempted task is a running task.
 	 */
-	if (task_preempt_count(p) & PREEMPT_ACTIVE)
+	if (task_preempt_count(p))
 		state = TASK_RUNNING | TASK_STATE_MAX;
 #endif
 
@@ -85,7 +85,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
 	/*
 	 * For all intents and purposes a preempted task is a running task.
 	 */
-	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
+	if (task_thread_info(p)->preempt_count)
 		state = TASK_RUNNING | TASK_STATE_MAX;
 #endif
 
@@ -102,7 +102,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
 	/*
 	 * For all intents and purposes a preempted task is a running task.
 	 */
-	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
+	if (task_thread_info(p)->preempt_count)
 		state = TASK_RUNNING;
 #endif
 
diff --git a/instrumentation/events/mainline/sched.h b/instrumentation/events/mainline/sched.h
index ea7a2035456d..790085190a4b 100644
--- a/instrumentation/events/mainline/sched.h
+++ b/instrumentation/events/mainline/sched.h
@@ -100,7 +100,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
 	/*
 	 * For all intents and purposes a preempted task is a running task.
 	 */
-	if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
+	if (task_thread_info(p)->preempt_count)
 		state = TASK_RUNNING | TASK_STATE_MAX;
 #endif
 
-- 
2.7.0