[Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Jan Kiszka]

Don't raise SIGXCPU while the process is being debugged. These mode
changes are expected, and reporting them doesn't provide any helpful
information to the application. Rather, it may raise error storms on the
application side.

Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
---

 ksrc/nucleus/shadow.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index bcf3b8b..91cf499 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -1082,7 +1082,8 @@ void xnshadow_relax(int notify)
 
 	xnstat_counter_inc(&thread->stat.ssw);	/* Account for secondary mode switch. */
 
-	if (notify && xnthread_test_state(thread, XNTRAPSW))
+	if (notify && xnthread_test_state(thread, XNTRAPSW) &&
+	    !xnthread_test_state(thread, XNDEBUG))
 		/* Help debugging spurious relaxes. */
 		send_sig(SIGXCPU, current, 1);
 

Re: [Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Philippe Gerum]

Jan Kiszka wrote:
> Don't raise SIGXCPU while the process is being debugged. These mode
> changes are expected, and reporting them doesn't provide any helpful
> information to the application. Rather, it may raise error storms on the
> application side.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
> ---
> 
>  ksrc/nucleus/shadow.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
> index bcf3b8b..91cf499 100644
> --- a/ksrc/nucleus/shadow.c
> +++ b/ksrc/nucleus/shadow.c
> @@ -1082,7 +1082,8 @@ void xnshadow_relax(int notify)
>  
>  	xnstat_counter_inc(&thread->stat.ssw);	/* Account for secondary mode switch. */
>  
> -	if (notify && xnthread_test_state(thread, XNTRAPSW))
> +	if (notify && xnthread_test_state(thread, XNTRAPSW) &&
> +	    !xnthread_test_state(thread, XNDEBUG))
>  		/* Help debugging spurious relaxes. */
>  		send_sig(SIGXCPU, current, 1);
>

I would rather identify the source of the switch and clear the notify flag 
appropriately from the relax call site.

> 
> _______________________________________________
> Xenomai-core mailing list
> Xenomai-core@domain.hid
> https://mail.gna.org/listinfo/xenomai-core
> 


-- 
Philippe.

Re: [Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Jan Kiszka]

Philippe Gerum wrote:
> Jan Kiszka wrote:
>> Don't raise SIGXCPU while the process is being debugged. These mode
>> changes are expected, and reporting them doesn't provide any helpful
>> information to the application. Rather, it may raise error storms on the
>> application side.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>> ---
>>
>>  ksrc/nucleus/shadow.c |    3 ++-
>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
>> index bcf3b8b..91cf499 100644
>> --- a/ksrc/nucleus/shadow.c
>> +++ b/ksrc/nucleus/shadow.c
>> @@ -1082,7 +1082,8 @@ void xnshadow_relax(int notify)
>>  
>>      xnstat_counter_inc(&thread->stat.ssw);    /* Account for
>> secondary mode switch. */
>>  
>> -    if (notify && xnthread_test_state(thread, XNTRAPSW))
>> +    if (notify && xnthread_test_state(thread, XNTRAPSW) &&
>> +        !xnthread_test_state(thread, XNDEBUG))
>>          /* Help debugging spurious relaxes. */
>>          send_sig(SIGXCPU, current, 1);
>>
> 
> I would rather identify the source of the switch and clear the notify
> flag appropriately from the relax call site.

Sorry, don't get this: What flag do you want to clear? XNTRAPSW?

Jan

-- 
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux

Re: [Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Philippe Gerum]

Jan Kiszka wrote:
> Philippe Gerum wrote:
>> Jan Kiszka wrote:
>>> Don't raise SIGXCPU while the process is being debugged. These mode
>>> changes are expected, and reporting them doesn't provide any helpful
>>> information to the application. Rather, it may raise error storms on the
>>> application side.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>> ---
>>>
>>>  ksrc/nucleus/shadow.c |    3 ++-
>>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
>>> index bcf3b8b..91cf499 100644
>>> --- a/ksrc/nucleus/shadow.c
>>> +++ b/ksrc/nucleus/shadow.c
>>> @@ -1082,7 +1082,8 @@ void xnshadow_relax(int notify)
>>>  
>>>      xnstat_counter_inc(&thread->stat.ssw);    /* Account for
>>> secondary mode switch. */
>>>  
>>> -    if (notify && xnthread_test_state(thread, XNTRAPSW))
>>> +    if (notify && xnthread_test_state(thread, XNTRAPSW) &&
>>> +        !xnthread_test_state(thread, XNDEBUG))
>>>          /* Help debugging spurious relaxes. */
>>>          send_sig(SIGXCPU, current, 1);
>>>
>> I would rather identify the source of the switch and clear the notify
>> flag appropriately from the relax call site.
> 
> Sorry, don't get this: What flag do you want to clear? XNTRAPSW?
>

The "notify" parameter should set by the call site to tell xnshadow_relax() 
whether we want the SIGXCPU signal to be sent or not. I would rather identify 
which call site introduces the issue, and fix the notify parameter accordingly. 
Did you track the issue down to request_syscall_restart() for instance? In which 
case, we should rather test XNDEBUG there, and set the notify flag passed to 
xnshadow_relax() appropriately.

> Jan
> 


-- 
Philippe.

Re: [Xenomai-core] [PATCH] Suppress switch warnings while debugging

[Jan Kiszka]

Philippe Gerum wrote:
> Jan Kiszka wrote:
>> Philippe Gerum wrote:
>>> Jan Kiszka wrote:
>>>> Don't raise SIGXCPU while the process is being debugged. These mode
>>>> changes are expected, and reporting them doesn't provide any helpful
>>>> information to the application. Rather, it may raise error storms on
>>>> the
>>>> application side.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>>> ---
>>>>
>>>>  ksrc/nucleus/shadow.c |    3 ++-
>>>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
>>>> index bcf3b8b..91cf499 100644
>>>> --- a/ksrc/nucleus/shadow.c
>>>> +++ b/ksrc/nucleus/shadow.c
>>>> @@ -1082,7 +1082,8 @@ void xnshadow_relax(int notify)
>>>>  
>>>>      xnstat_counter_inc(&thread->stat.ssw);    /* Account for
>>>> secondary mode switch. */
>>>>  
>>>> -    if (notify && xnthread_test_state(thread, XNTRAPSW))
>>>> +    if (notify && xnthread_test_state(thread, XNTRAPSW) &&
>>>> +        !xnthread_test_state(thread, XNDEBUG))
>>>>          /* Help debugging spurious relaxes. */
>>>>          send_sig(SIGXCPU, current, 1);
>>>>
>>> I would rather identify the source of the switch and clear the notify
>>> flag appropriately from the relax call site.
>>
>> Sorry, don't get this: What flag do you want to clear? XNTRAPSW?
>>
> 
> The "notify" parameter should set by the call site to tell
> xnshadow_relax() whether we want the SIGXCPU signal to be sent or not. I
> would rather identify which call site introduces the issue, and fix the
> notify parameter accordingly. Did you track the issue down to
> request_syscall_restart() for instance? In which case, we should rather
> test XNDEBUG there, and set the notify flag passed to xnshadow_relax()
> appropriately.

OK, now I understand. I didn't track this down yet, but it must be
request_syscall_restart, because that should be the only site that
relaxes due to pending signals. Will update the patch.

Jan

-- 
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux

[Xenomai-core] [PATCH v2] Suppress switch warnings while debugging

[Jan Kiszka]

Don't raise SIGXCPU while the process is being debugged. These mode
changes are expected, and reporting them doesn't provide any helpful
information to the application. Rather, it may raise error storms on the
application side.

Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
---

 ksrc/nucleus/shadow.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index bcf3b8b..12b4073 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -667,7 +667,7 @@ static inline void request_syscall_restart(xnthread_t *thread,
 			__xn_error_return(regs,
 					  (sysflags & __xn_exec_norestart) ?
 					  -ERESTARTNOHAND : -ERESTARTSYS);
-			notify = 1;
+			notify = !xnthread_test_state(thread, XNDEBUG);
 		}
 
 		xnthread_clear_info(thread, XNKICKED);