Environment Variables

This section describes the environment variables that may need to be configured for using HTL. Set the environment variables as required after installing KSL.

**Table 1** Environment variables of HTL
Variable	Description	Default Value
HTL_THREAD_STACKSIZE	Sets the thread stack size, in bytes.	16384
HTL_SCHED_SLEEP_NSEC	Sets the scheduler sleep mode (nanosleep).	100
HTL_MEM_MAX_NUM_STACKS	Sets the maximum number of stacks that can be reserved by an executor.	65536
HTL_MAX_NUM_XSTREAMS	Sets the number of executors in HTL-PThreads mode.	Number of processors in the system

The following uses HTL_THREAD_STACKSIZE as an example to describe how to configure environment variables.

Open the /etc/profile file.
```
vi /etc/profile
```
Press i to enter the insert mode and add the following content to the /etc/profile file.
```
export HTL_THREAD_STACKSIZE=16384
```
Run the source command for the environment variable to take effect.
```
source /etc/profile
```

Parent topic: Data Structures