diff options
Diffstat (limited to 'nuttx/syscall/Kconfig')
| -rw-r--r-- | nuttx/syscall/Kconfig | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/nuttx/syscall/Kconfig b/nuttx/syscall/Kconfig index 6e047012a..0c5b74ab1 100644 --- a/nuttx/syscall/Kconfig +++ b/nuttx/syscall/Kconfig @@ -5,6 +5,8 @@ if NUTTX_KERNEL +comment "System call configuration" + config SYS_RESERVED int "Number of reserved system calls" default 0 @@ -16,4 +18,20 @@ config SYS_RESERVED architecture; number of the kernel system calls will begin with this number. +config SYS_NNEST + int "Number of nested system calls" + default 2 + ---help--- + This is architecture dependent. Most architectures allocate + resources to manage a fixed, maximum number of nested system calls. + A nested system call occurs in the following scenario: (1) A non- + privileged user thread executes a system call, (2) part of the + system call processing cause a call back into the user space code, + and (3) the user space code performs another system call. + + In the current design, this can happen only under one condition: + When the kernel calls back into user space in order to allocate user + space memory. So it is expected that the maximum nesting level will + be only 2. + endif |