On Wednesday 27 August 2008, Roger Oberholtzer wrote:
On Wed, 2008-08-27 at 11:28 +0200, Wilfred van Velzen wrote:
Interesting link. Not using this. It is describing the issue of non-restartable system calls. We always set up our signal handlers to specify SA_RESTART. But our problem happens even when the application does not get a signal or other asynchronous interrupt.
We have no trouble with a read() call getting interrupted by some signal to the program. Occasional read returns with no data or incomplete data are no problem. What happens in our case is that the reads start returning immediately. So the application is suddenly using all available CPU time because it is doing reads as fast as it can, with only 1 in a 1000 actually providing data.
I forgot to mention that I use strace to see all that is happening.
-- Roger Oberholtzer
OPQ Systems / Ramböll RST
Ramböll Sverige AB Kapellgränd 7 P.O. Box 4205 SE-102 65 Stockholm, Sweden
Office: Int +46 8-615 60 20 Mobile: Int +46 70-815 1696
And remember:
It is RSofT and there is always something under construction. It is like talking about large city with all constructions finished. Not impossible, but very unlikely.
Hi . I take it this system is mounted in some sort of vehicle you have of course made certain it is not a spike or other such electrical interference getting into the cable some how or somewhere else in the system . I have been designing and building an control system for a friends sons rally car and have had lots of trouble with spikes ect causing real havoc even stopping the car dead Pete . -- SuSE Linux 10.3-Alpha3. (Linux is like a wigwam - no Gates, no Windows, and an Apache inside.) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org