Hi, I want to build a Kamailio version without the usage of futex. First of all I notice that the variable "use_futex" within Makefile.defs is hardcoded to the value "yes". Why is that? I want to get rid of this and build Kamailio without futex support. In the same file there are GCC options like -DUSE_PTHREAD_MUTEX, -DUSE_POSIX_SEM etc. So I disabled the line use_futex and and added -DUSE_PTHREAD_MUTEX as follows; #use_futex= yes C_DEFS+=-DUSE_PTHREAD_MUTEX After building Kamailio with these options: Although the output of "kamailio -I" indicates that FUTEX is not used (PTHREAD_MUTEX is used instead) it still uses futex sneaky as its locking mechanism. I can see this after catting the content of /proc/<pid>/wchan. This is because Kamailio hangs on futex after running it a while (see our other issue in the topic "Kamailio stability/timing problem w.r.t. registrations?"). Question is; How can I build Kamailio with a locking mechanism other than FUTEX? And why does the solution with Makefile.defs not work? PS: Kernel version is 2.6.30 on an ARM platform Thanks for your support. Kind regards, Orhan Yilmaz