Hi Nagu, I agree with Ramesh, e.g. in the child part:
/* By default we close all inherited file descriptors in the child */
if (getenv("OPENSAF_KEEP_FD_OPEN_AFTER_FORK") == NULL) {
/* Close all inherited file descriptors */
int i = sysconf(_SC_OPEN_MAX);
if (i == -1) {
syslog(LOG_ERR, "%s: sysconf failed - %s",
__FUNCTION__, strerror(errno));
exit(EXIT_FAILURE);
}
for (i--; i >= 0; --i)
(void) close(i); /* close all descriptors */
/* Redirect standard files to /dev/null */
if (freopen("/dev/null", "r", stdin) == NULL)
syslog(LOG_ERR, "%s: freopen stdin failed - %s",
__FUNCTION__, strerror(errno));
if (freopen("/dev/null", "w", stdout) == NULL)
syslog(LOG_ERR, "%s: freopen stdout failed - %s",
__FUNCTION__, strerror(errno));
if (freopen("/dev/null", "w", stderr) == NULL)
syslog(LOG_ERR, "%s: freopen stderr failed - %s",
__FUNCTION__, strerror(errno));
}
close are issued.
/BR HansN
On 07/30/13 12:34, Nagendra Kumar wrote:
> But where are file operations coming during fork, can you please explain ?
>
> Thanks
> -Nagu
> -----Original Message-----
> From: Ramesh Betham
> Sent: 30 July 2013 15:53
> To: Nagendra Kumar
> Cc: Hans Nordebäck; [email protected]; Praveen Malviya;
> Hans Feldt
> Subject: Re: [PATCH 1 of 1] leap: ncs_os_process_execute_timed child process
> takes too long time before exec (#514)
>
> Nagu: Hans N might be pointing to the chances of hung of file-operation calls
> (esp. when some inconsistency happens with NFS). Just a guess, let Hans N
> confirm it.
>
> Thanks,
> Ramesh.
>
> On 7/30/2013 3:27 PM, Nagendra Kumar wrote:
>> Hi,
>>
>>>> regarding what can "hang" in the child part, e.g close of file descriptors
>>>> close of file descriptors.
>> When this can happen? After fork is successful, this shouldn't happen. Can
>> you please provide any example.
>>
>> Thanks
>> -Nagu
>>
>> -----Original Message-----
>> From: Hans Nordebäck [mailto:[email protected]]
>> Sent: 30 July 2013 12:53
>> To: Nagendra Kumar
>> Cc: Hans Nordebäck; [email protected]; Praveen
>> Malviya; Ramesh Babu Betham; Hans Feldt
>> Subject: Re: [PATCH 1 of 1] leap: ncs_os_process_execute_timed child
>> process takes too long time before exec (#514)
>>
>> Hi Nagu, regarding what can "hang" in the child part, e.g close of file
>> descriptors. /BR HansN On 07/30/13 09:01, Hans Nordebäck wrote:
>>> Hi Nagu,
>>>
>>> On 07/30/13 08:54, Nagendra Kumar wrote:
>>>> Hi Hans N,
>>>>
>>>>>> 1. OPENSAF_CHILD_EXEC_TIME_TOLERANCE is the name of a new
>>>>>> environment variable where value is used as input to alarm, if
>>>>>> not set it is default 2 seconds.
>>>> Do we have some place holder for this variable for configuration and
>>>> are we going to add it in README for information.
>>> Perhaps the name isn't the best, but it should be handled as the
>>> other env variable I guess, e.g. "AVND_PM_MONITORING_RATE", etc.
>>>>>> if the child "hangs" before exec this extra coredump should give
>>>>>> information where/what is wrong.
>>>> This means that fork hangs, am I right ? If yes, then dump is not
>>>> going to provide any information as it is a system call, it can only
>>>> show, ithangs in fork.
>>> I don't think fork hangs as the parent part continues and later, with
>>> the help of ncs_exec_mod_hdlr, the parent detects that the child or
>>> "exec" has timed out,
>>> 10 sec in this case. But in this case the exec has not been performed.
>>>>>> After exec, it will work as usual
>>>> This confirms that we are only targeting fork to debug.
>>> Yes, the extra core dump will help troubleshooting.
>>> /BR HansN
>>>> Thanks
>>>> -Nagu
>>>>
>>>> -----Original Message-----
>>>> From: Hans Nordebäck [mailto:[email protected]]
>>>> Sent: 30 July 2013 11:57
>>>> To: Nagendra Kumar
>>>> Cc: [email protected]; Praveen Malviya; Ramesh
>>>> Babu Betham; Hans Feldt; Hans Nordebäck
>>>> Subject: RE: [PATCH 1 of 1] leap: ncs_os_process_execute_timed child
>>>> process takes too long time before exec (#514)
>>>>
>>>> Hi Nagu,
>>>>
>>>> 1. OPENSAF_CHILD_EXEC_TIME_TOLERANCE is the name of a new
>>>> environment variable where value is used as input to alarm, if not
>>>> set it is default 2 seconds.
>>>> 2. Yes you are right, in this particular case it is set to 10 sec,
>>>> that's why the env. variable above can be set.
>>>> 3. This alarm is just an additional precaution, at no extra cost,
>>>> to check the child part before the exec. After exec
>>>> it will work as usual but if the child "hangs" before exec
>>>> this extra coredump should give information where/what is wrong.
>>>>
>>>> /BR HansN
>>>>
>>>> -----Original Message-----
>>>> From: Nagendra Kumar [mailto:[email protected]]
>>>> Sent: den 30 juli 2013 07:11
>>>> To: Hans Nordebäck; Praveen Malviya; Hans Feldt; Ramesh Babu Betham
>>>> Cc: [email protected]
>>>> Subject: RE: [PATCH 1 of 1] leap: ncs_os_process_execute_timed child
>>>> process takes too long time before exec (#514)
>>>>
>>>> Hi Hans N,
>>>> For my understanding, can you please provide the below
>>>> information:
>>>>
>>>> 1. I can't find OPENSAF_CHILD_EXEC_TIME_TOLERANCE in opensaf
>>>> source code.
>>>> 2. I hope the child process is hung for more than
>>>> saAmfCtDefClcCliTimeout resulting in CLC time out. Am I right?
>>>> 3. Even we add assert in child process and we get core dump, but
>>>> it may not give any information as it got delayed because of
>>>> system issue. Are we targeting, which system call the child
>>>> process is hung?
>>>>
>>>> Thanks
>>>> -Nagu
>>>>
>>>> -----Original Message-----
>>>> From: Hans Nordeback [mailto:[email protected]]
>>>> Sent: 22 July 2013 17:07
>>>> To: Nagendra Kumar; Praveen Malviya; [email protected]; Ramesh
>>>> Babu Betham
>>>> Cc: [email protected]
>>>> Subject: [PATCH 1 of 1] leap: ncs_os_process_execute_timed child
>>>> process takes too long time before exec (#514)
>>>>
>>>> osaf/libs/core/leap/os_defs.c | 27 +++++++++++++++++++++++++++
>>>> 1 files changed, 27 insertions(+), 0 deletions(-)
>>>>
>>>>
>>>> amfnd calls ncs_os_process_execute_timed and the child process takes
>>>> too long time before exec, (10 sec timeout). An alarm is set in the
>>>> ncs_os_process_execute_timed child process. If timed out a core dump
>>>> will be produced to be able to trouble shoot.
>>>>
>>>> diff --git a/osaf/libs/core/leap/os_defs.c
>>>> b/osaf/libs/core/leap/os_defs.c
>>>> --- a/osaf/libs/core/leap/os_defs.c
>>>> +++ b/osaf/libs/core/leap/os_defs.c
>>>> @@ -65,6 +65,15 @@ bool gl_ncs_atomic_mtx_initialise = fals
>>>> * description of SOCK_CLOEXEC. */
>>>> static pthread_mutex_t s_cloexec_mutex = PTHREAD_MUTEX_INITIALIZER;
>>>> +/*
>>>> + * ALRM signal is used to detect if child process takes too long
>>>> time before exec.
>>>> + *
>>>> + * @param sig
>>>> + */
>>>> +static void sigalrm_handler(int sig) {
>>>> + abort();
>>>> +}
>>>> /***************************************************************************
>>>> *
>>>> * uns64
>>>> @@ -999,6 +1008,22 @@ uint32_t ncs_os_process_execute_timed(NC
>>>> osaf_mutex_lock_ordie(&s_cloexec_mutex);
>>>> if ((pid = fork()) == 0) {
>>>> + unsigned int alarm_time_sec;
>>>> + char* alarm_time;
>>>> +
>>>> + if (signal(SIGALRM, sigalrm_handler) == SIG_ERR) {
>>>> + LOG_ER("signal ALRM failed: %s",
>>>> strerror(errno));
>>>> + }
>>>> + if ((alarm_time =
>>>> getenv("OPENSAF_CHILD_EXEC_TIME_TOLERANCE")) != NULL) {
>>>> + alarm_time_sec = strtol(alarm_time, NULL, 0);
>>>> + }
>>>> + else {
>>>> + // default alarm timeout 2 seconds
>>>> + alarm_time_sec = 2;
>>>> + }
>>>> +
>>>> + alarm(alarm_time_sec);
>>>> +
>>>> /*
>>>> ** Make sure forked processes have default scheduling class
>>>> ** independent of the callers scheduling class.
>>>> @@ -1054,6 +1079,8 @@ uint32_t ncs_os_process_execute_timed(NC
>>>> }
>>>> #endif
>>>> + alarm(0);
>>>> +
>>>> /* child part */
>>>> if (execvp(req->i_script, req->i_argv) == -1) {
>>>> syslog(LOG_ERR, "%s: execvp '%s' failed - %s",
>>>> __FUNCTION__, req->i_script, strerror(errno));
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