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* [PATCH] tracing: use assign_bit() where applicable
@ 2026-09-20  2:28 Peng Fan (OSS)
  2026-09-20 11:21 ` Steven Rostedt
  0 siblings, 1 reply; 3+ messages in thread
From: Peng Fan (OSS) @ 2026-09-20  2:28 UTC (permalink / raw)
  To: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers
  Cc: linux-kernel, Peng Fan, linux-trace-kernel

From: Peng Fan <peng.fan@nxp.com>

Convert open-coded if/else with set_bit/clear_bit the assign_bit API.

Done with Coccinelle semantic patch:
    // set_bit -> clear_bit => assign_bit

    @@
    expression cond, bit, addr;
    @@

    -if (cond)
    -        set_bit(bit, addr);
    -else
    -        clear_bit(bit, addr);
    +assign_bit(bit, addr, cond);

    // clear_bit -> set_bit => assign_bit

    @@
    expression cond, bit, addr;
    @@

    -if (cond)
    -        clear_bit(bit, addr);
    -else
    -        set_bit(bit, addr);
    +assign_bit(bit, addr, !cond);

    // __set_bit -> __clear_bit => __assign_bit

    @@
    expression cond, bit, addr;
    @@

    -if (cond)
    -        __set_bit(bit, addr);
    -else
    -        __clear_bit(bit, addr);
    +__assign_bit(bit, addr, cond);

    // __clear_bit -> __set_bit => __assign_bit

    @@
    expression cond, bit, addr;
    @@

    -if (cond)
    -        __clear_bit(bit, addr);
    -else
    -        __set_bit(bit, addr);
    +__assign_bit(bit, addr, !cond);

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 kernel/trace/trace_events.c         | 12 ++++--------
 kernel/trace/trace_events_trigger.c | 11 +++--------
 kernel/trace/trace_events_user.c    |  5 +----
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 30c0ddf90887..72a210da67d6 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -859,10 +859,8 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
 			WARN_ON_ONCE(ret);
 		}
 		/* If in soft mode, just set the SOFT_DISABLE_BIT, else clear it */
-		if (soft_mode)
-			set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
-		else
-			clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
+		assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags,
+			   soft_mode);
 		break;
 	case 1:
 		/*
@@ -4273,10 +4271,8 @@ struct event_probe_data {
 
 static void update_event_probe(struct event_probe_data *data)
 {
-	if (data->enable)
-		clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
-	else
-		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
+	assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags,
+		   !data->enable);
 }
 
 static void
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 4d2fde996c0f..3b5e14fd0dd9 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -674,10 +674,7 @@ void update_cond_flag(struct trace_event_file *file)
 		}
 	}
 
-	if (set_cond)
-		set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
-	else
-		clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
+	assign_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags, set_cond);
 }
 
 /**
@@ -1673,10 +1670,8 @@ event_enable_trigger(struct event_trigger_data *data,
 {
 	struct enable_trigger_data *enable_data = data->private_data;
 
-	if (enable_data->enable)
-		clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
-	else
-		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
+	assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags,
+		   !enable_data->enable);
 }
 
 static bool
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index f658c3a77aa7..055894cb999c 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -590,10 +590,7 @@ static int user_event_enabler_write(struct user_event_mm *mm,
 	ptr = kaddr + (uaddr & ~PAGE_MASK);
 
 	/* Update bit atomically, user tracers must be atomic as well */
-	if (enabler->event && enabler->event->status)
-		set_bit(bit, ptr);
-	else
-		clear_bit(bit, ptr);
+	assign_bit(bit, ptr, enabler->event && enabler->event->status);
 
 	kunmap_local(kaddr);
 	unpin_user_pages_dirty_lock(&page, 1, true);
-- 
2.51.0


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] tracing: use assign_bit() where applicable
  2026-09-20  2:28 [PATCH] tracing: use assign_bit() where applicable Peng Fan (OSS)
@ 2026-09-20 11:21 ` Steven Rostedt
  2026-09-21  6:31   ` Peng Fan
  0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2026-09-20 11:21 UTC (permalink / raw)
  To: Peng Fan (OSS)
  Cc: Masami Hiramatsu, Mathieu Desnoyers, linux-kernel, Peng Fan,
	linux-trace-kernel

On Sun, 20 Sep 2026 10:28:10 +0800
"Peng Fan (OSS)" <peng.fan@oss.nxp.com> wrote:

> From: Peng Fan <peng.fan@nxp.com>
> 
> Convert open-coded if/else with set_bit/clear_bit the assign_bit API.
> 
> Done with Coccinelle semantic patch:
>     // set_bit -> clear_bit => assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        set_bit(bit, addr);
>     -else
>     -        clear_bit(bit, addr);
>     +assign_bit(bit, addr, cond);
> 
>     // clear_bit -> set_bit => assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        clear_bit(bit, addr);
>     -else
>     -        set_bit(bit, addr);
>     +assign_bit(bit, addr, !cond);
> 
>     // __set_bit -> __clear_bit => __assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        __set_bit(bit, addr);
>     -else
>     -        __clear_bit(bit, addr);
>     +__assign_bit(bit, addr, cond);
> 
>     // __clear_bit -> __set_bit => __assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        __clear_bit(bit, addr);
>     -else
>     -        __set_bit(bit, addr);
>     +__assign_bit(bit, addr, !cond);
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  kernel/trace/trace_events.c         | 12 ++++--------
>  kernel/trace/trace_events_trigger.c | 11 +++--------
>  kernel/trace/trace_events_user.c    |  5 +----
>  3 files changed, 8 insertions(+), 20 deletions(-)
> 
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 30c0ddf90887..72a210da67d6 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -859,10 +859,8 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
>  			WARN_ON_ONCE(ret);
>  		}
>  		/* If in soft mode, just set the SOFT_DISABLE_BIT, else clear it */
> -		if (soft_mode)
> -			set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
> -		else
> -			clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
> +		assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags,
> +			   soft_mode);

Please make it a single line. tracing is not strict about the 80 line
limit if it makes it look worse.

>  		break;
>  	case 1:
>  		/*
> @@ -4273,10 +4271,8 @@ struct event_probe_data {
>  
>  static void update_event_probe(struct event_probe_data *data)
>  {
> -	if (data->enable)
> -		clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
> -	else
> -		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
> +	assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags,
> +		   !data->enable);

Ditto.

>  }
>  
>  static void
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index 4d2fde996c0f..3b5e14fd0dd9 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -674,10 +674,7 @@ void update_cond_flag(struct trace_event_file *file)
>  		}
>  	}
>  
> -	if (set_cond)
> -		set_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
> -	else
> -		clear_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags);
> +	assign_bit(EVENT_FILE_FL_TRIGGER_COND_BIT, &file->flags, set_cond);
>  }
>  
>  /**
> @@ -1673,10 +1670,8 @@ event_enable_trigger(struct event_trigger_data *data,
>  {
>  	struct enable_trigger_data *enable_data = data->private_data;
>  
> -	if (enable_data->enable)
> -		clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
> -	else
> -		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
> +	assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags,
> +		   !enable_data->enable);

Ditto.

Thanks,

-- Steve
 
>  }
>  
>  static bool
> diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
> index f658c3a77aa7..055894cb999c 100644
> --- a/kernel/trace/trace_events_user.c
> +++ b/kernel/trace/trace_events_user.c
> @@ -590,10 +590,7 @@ static int user_event_enabler_write(struct user_event_mm *mm,
>  	ptr = kaddr + (uaddr & ~PAGE_MASK);
>  
>  	/* Update bit atomically, user tracers must be atomic as well */
> -	if (enabler->event && enabler->event->status)
> -		set_bit(bit, ptr);
> -	else
> -		clear_bit(bit, ptr);
> +	assign_bit(bit, ptr, enabler->event && enabler->event->status);
>  
>  	kunmap_local(kaddr);
>  	unpin_user_pages_dirty_lock(&page, 1, true);


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] tracing: use assign_bit() where applicable
  2026-09-20 11:21 ` Steven Rostedt
@ 2026-09-21  6:31   ` Peng Fan
  0 siblings, 0 replies; 3+ messages in thread
From: Peng Fan @ 2026-09-21  6:31 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Masami Hiramatsu, Mathieu Desnoyers, linux-kernel, Peng Fan,
	linux-trace-kernel

On Sun, Sep 20, 2026 at 07:21:51AM -0400, Steven Rostedt wrote:
>On Sun, 20 Sep 2026 10:28:10 +0800
>"Peng Fan (OSS)" <peng.fan@oss.nxp.com> wrote:
>
>> From: Peng Fan <peng.fan@nxp.com>
>> 
>> Convert open-coded if/else with set_bit/clear_bit the assign_bit API.
>> 
>> Done with Coccinelle semantic patch:
>>  /**
>> @@ -1673,10 +1670,8 @@ event_enable_trigger(struct event_trigger_data *data,
>>  {
>>  	struct enable_trigger_data *enable_data = data->private_data;
>>  
>> -	if (enable_data->enable)
>> -		clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
>> -	else
>> -		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
>> +	assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags,
>> +		   !enable_data->enable);
>
>Ditto.

This will exceeds 100 columns. Should I keep as it is using two lines?

WARNING: line length of 101 exceeds 100 columns
#116: FILE: kernel/trace/trace_events_trigger.c:1673:
+       assign_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags, !enable_data->enable);

Thanks,
Peng

>
>Thanks,
>
>-- Steve
> 
>>  }
>>  
>>  static bool
>> diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
>> index f658c3a77aa7..055894cb999c 100644
>> --- a/kernel/trace/trace_events_user.c
>> +++ b/kernel/trace/trace_events_user.c
>> @@ -590,10 +590,7 @@ static int user_event_enabler_write(struct user_event_mm *mm,
>>  	ptr = kaddr + (uaddr & ~PAGE_MASK);
>>  
>>  	/* Update bit atomically, user tracers must be atomic as well */
>> -	if (enabler->event && enabler->event->status)
>> -		set_bit(bit, ptr);
>> -	else
>> -		clear_bit(bit, ptr);
>> +	assign_bit(bit, ptr, enabler->event && enabler->event->status);
>>  
>>  	kunmap_local(kaddr);
>>  	unpin_user_pages_dirty_lock(&page, 1, true);
>
>
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2026-09-21  6:27 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2026-09-20  2:28 [PATCH] tracing: use assign_bit() where applicable Peng Fan (OSS)
2026-09-20 11:21 ` Steven Rostedt
2026-09-21  6:31   ` Peng Fan

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