Summary:	ASTERISK-02851: Request for informed comment on behaviour of wctdm driver
Reporter:	richard (richard)	Labels:
Date Opened:	2004-11-18 12:55:42.000-0600	Date Closed:	2011-06-07 14:10:33
Priority:	Minor	Regression?	No
Status:	Closed/Complete	Components:	Core/General
Versions:		Frequency of Occurrence
Related Issues:
Environment:		Attachments:
Description:	Loading the wctdm driver on 2 machines, shows regular system CPU peaks of 100%, for periods of several seconds. Is this a) normal behaviour, b) a measurement anomaly or c) some sort of race or misbehaviour in the driver. ****** ADDITIONAL INFORMATION ****** The systems are very simple - analog only, no SIP etc., G711 ulaw codec only, no voicemail, conferencing or MOH and the 2 systems are IAX2-ed together. Both boxes have a very minimal Redhat 7.3 install, with a custom compiled 2.4.27 kernel containing only what is necessary for Asterisk. CVS updates have been done on a weekly basis and this behaviour has always been observed over a period of 18 months. Hardware-wise, both are identical P4 2.4, Intel 845 chipset machines, single IDE, the only difference is one has a single TDM400 with 4 x FXO and the other has 1 x TDM400 with 2 x FXO and 2 x TDM400, each with 4 FXS. With Asterisk not running, and just the wctdm driver loaded and no activity on the machine, the output of "vmstat 1" shows this on the box with only one TDM card:   system      cpu    in    cs  us  sy  id  1113     5   0   0 100  1114     7   0  52  48  1113     7   0 100   0  1114     5   0 100   0  1113     5   0 100   0  1113     5   0  10  90  1113     7   0   0 100  1113     7   0   0 100  1113     5   0   0 100  1113     5   0   0 100  1113     5   0   0 100  1113     7   0   0 100  1117     7   0   0 100  1113     5   0   0 100  1113     5   0   0 100  1113     5   0   0 100  1113     7   0   0 100  1113     7   0   0 100  1113     5   0   0 100  1114     5   0   0 100  1112     7   0   0 100  1113     7   0   0 100  1112     8   0   0 100  1113     7   0   0 100  1113     5   0   0 100  1113     5   0  29  71  1113     7   0 100   0  1113     7   0 100   0  1113     5   0 100   0  1113     5   0  32  68  1114     5   0   0 100  1113     7   0   0 100  1113     7   0   0 100  1113     5   0   0 100 This CPU usage pattern repeats at the same interval. The other box with 3 TDM400s shows:   system      cpu    in    cs  us  sy  id  3123     5   0   0 100  3135    14   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   9  91  3133     8   0  50  50  3133     5   0  50  50  3133     5   0  50  50  3133     5   0  50  50  3133     5   0  50  50  3145     8   0  50  50  3133     5   0  50  50  3133     5   0  48  52  3133     5   0   0 100  3133     5   0   0 100  3133     8   0   0 100  3137     5   0   0 100  3132     5   0   0 100  3134     5   0   0 100  3132     5   0   0 100  3134     8   0   0 100  3132     6   0   0 100  3134     5   0   0 100  3132     5   0   0 100  3134     5   0   0 100  3132     8   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3149     9   0   0 100  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   2  98  3133     5   0   2  98  3133     8   0   1  99  3133     5   0   2  98  3133     5   0  80  20  3133     5   0 100   0  3133     5   0 100   0  3133     8   0  26  74  3133     5   0   0 100  3133     5   0   0 100  3133     5   0   0 100 Again, this CPU load pattern repeats at the same interval, alternating bursts of 50% sys CPU and shorter bursts of 100% sys. I am interested in this, as the systems are prone to quite intermitent problems, and I am wondering if these may be caused by calls coinciding with the periods of high CPU usage.
Comments:	By: Russell Bryant (russell) 2004-11-18 13:54:02.000-0600 This is a Digium technical support issue.  Please contact Digium technical support for help on this issue. A link was highlighted in yellow asking you to read the bug guidelines before placing a bug.  Number 3 of the bug guidelines states: Do not place bugs about trouble you are having with your hardware (e.g. inability to load drivers, modules or cards that are acting up) unless directed to do so by Digium. Thank you!