native: arch: added recommended stack size config

Added a new config variable with the recommended stack
size for threads which are only meant for the posix architecture

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

arch/posix/Kconfig

@@ -25,6 +25,16 @@ config ARCH_DEFCONFIG
 
 source "arch/posix/core/Kconfig"
 
+config ARCH_POSIX_RECOMMENDED_STACK_SIZE
+	int
+	depends on ARCH_POSIX
+	default 24
+	help
+	  In bytes, stack size for Zephyr threads meant only for the POSIX
+	  architecture.
+	  (In this architecture only part of the thread status is kept in the Zephyr
+	  thread stack, the real stack is the native underlying pthread stack.
+	  Therefore the allocated stack can be limited to this size)
 
 source "arch/posix/soc/*/Kconfig"
 

arch/posix/include/posix_core.h

@@ -26,6 +26,12 @@ typedef struct {
 	/* times */
 	int aborted;
 #endif
+
+	/*
+	 * Note: If more elements are added to this structure, remember to
+	 * update ARCH_POSIX_RECOMMENDED_STACK_SIZE in the configuration
+	 * Currently it is 24 = 4 pointers + 2 ints = 4*4 + 2*4
+	 */
 } posix_thread_status_t;