Roderik_Wildenburg@domain.hid wrote: > Does any of the memory functions like : > memcopy, > memset, > bzero, > > : > : > > cause Xenomai to switch to secondary mode ? > I am asking as I have a high priority task, which mesures its > periodicity (set to 1ms). > This task is using just rt_-functions and memcpy. > When in low priority tasks memory intensively is used (memset, > rt_heap_alloc, rt_heap_create, NFS-transfers in Linux threads), the > cycle time of the high priority task inreases to nearly twice the time > it has been set up (2ms++; at least 1 time, as I just measure maxima). > > Is this possible, or am I doing something wrong ? Try catching unwanted context switches via the SIGXCPU signal. Given you have a sane glibc, non of those functions should cause a context switch - unless you touch some piece of memory for the first time (lazy mapping...). [Unfortunately, the I-pipe tracer is only available over 2.6 so far. Otherwise, putting a xntrace_user_freeze() right at that line in your application where you detect the deadline miss would give a nice view back in history.] Jan