Messages in this thread |  | | Date | Fri, 23 Aug 1996 12:04:39 +0200 | From | (Harald Kirsch) | Subject | Re: SCHED_FIFO: sleep times longer than expected (AGAIN) |
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>> rti834 overflow, status=0x14a8, last sleep=0.075978 >> stamp[63] = 0.001496 at 840787263.009563 by timer >> stamp[62] = 0.000074 at 840787263.008067 by read >> stamp[61] = 0.008468 at 840787263.007993 by wait/end >> stamp[60] = 0.010016 at 840787262.999525 by timer >> stamp[59] = 0.009966 at 840787262.989509 by timer >> stamp[58] = 0.010019 at 840787262.979543 by timer >> stamp[57] = 0.010085 at 840787262.969524 by timer >> stamp[56] = 0.010007 at 840787262.959439 by timer >> stamp[55] = 0.009890 at 840787262.949432 by timer >> stamp[54] = 0.007545 at 840787262.939542 by timer >> stamp[53] = 0.000995 at 840787262.931997 by wait/start >> stamp[52] = 0.000074 at 840787262.931002 by read >> stamp[51] = 0.000474 at 840787262.930928 by wait/end >> stamp[50] = 0.008822 at 840787262.930454 by timer >> stamp[49] = 0.000863 at 840787262.921632 by wait/start > >if i read your log right, then your program is blocking on a read() >operation. Thats pretty much normal ... there is no "looping", your >program is waiting for the read request to finish. > >run a program that does something like this: > > for(;;); > >and if >this< program gets interrupted for 100 msecs, then we have a >problem :) > >-- mingo
The stamps are written by my driver and 'wait/start' is the stamp immediately before interuptible_sleep_on, while 'wait/end' is in the source line after interuptible_sleep_on. Whenever the log says 'timer', wake_up is called, i.e. we should see a 'wait/end' immediately afterwards (because the process is SCHED_FIFO), like at stamp[50], stamp[51]. There would probably be no 'read' stamp, because no data is yet available from the hardware, but certainly 'wait/end' should show up immediatly after a 'timer' stamp.
Harald.
-------------------------------------------------+------------------ Harald Kirsch, kir@iitb.fhg.de, +49 721 6091 384 | This message is FhG/IITB, Fraunhoferstr.1, 76131 Karlsruhe | subject oriented.
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