_EDC_PTHREAD_YIELD

Used to control when pthread_yield() and sched_yield() will allow a thread to give up control of a processor so that another thread may have the opportunity to run. Possible values for _EDC_PTHREAD_YIELD:
0
Control of the processor is released immediately.
-1
Use an internal timing algorithm to determine if the processor should be released. This is the default.
-2
Take the machine speed into account when determining if the processor should be released.
other negative values
Invalid. The default (-1) will be used.
Notes:
  1. _EDC_PTHREAD_YIELD may be changed by setenv() while the |application is running. All threads will use the new value.
  2. The use of _EDC_PTHREAD_YIELD=-2 is suggested.
Examples of setting _EDC_PTHREAD_YIELD:
export _EDC_PTHREAD_YIELD=-1
set the ENVAR("_EDC_PTHREAD_YIELD=-2") runtime option