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Diffstat (limited to '')
-rw-r--r-- | doc/user/task.t | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/doc/user/task.t b/doc/user/task.t index 8ab2ecdb2f..e8a3390665 100644 --- a/doc/user/task.t +++ b/doc/user/task.t @@ -744,11 +744,37 @@ This directive will not cause the calling task to be preempted. Valid task priorities range from a high of 1 to a low of 255. -If the requested stack size is less than -@code{@value{RPREFIX}MINIMUM_STACK_SIZE} bytes, then RTEMS -will use @code{@value{RPREFIX}MINIMUM_STACK_SIZE} as the -stack size. The value of @code{@value{RPREFIX}MINIMUM_STACK_SIZE} -is processor dependent. +If the requested stack size is less than the configured +minimum stack size, then RTEMS will use the configured +minimum as the stack size for this task. In addition +to being able to specify the task stack size as a integer, +there are two constants which may be specified: + +@itemize @bullet +@item @code{@value{RPREFIX}MINIMUM_STACK_SIZE} +is the minimum stack size @b{RECOMMENDED} for use on this processor. +This value is selected by the RTEMS developers conservatively to +minimize the risk of blown stacks for most user applications. +Using this constant when specifying the task stack size, indicates +that the stack size will be at least +@code{@value{RPREFIX}MINIMUM_STACK_SIZE} bytes in size. If the +user configured minimum stack size is larger than the recommended +minimum, then it will be used. + +@item @code{@value{RPREFIX}CONFIGURED_MINIMUM_STACK_SIZE} +indicates that this task is to be created with a stack size +of the minimum stack size that was configured by the application. +If not explicitly configured by the application, the default +configured minimum stack size is the processor dependent value +@code{@value{RPREFIX}MINIMUM_STACK_SIZE}. Since this uses +the configured minimum stack size value, you may get a stack +size that is smaller or larger than the recommended minimum. This +can be used to provide large stacks for all tasks on complex +applications or small stacks on applications that are trying +to conserve memory. + +@end itemize + Application developers should consider the stack usage of the device drivers when calculating the stack size required for tasks which utilize the driver. |