diff options
| -rw-r--r-- | doc/intro.9.txt | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/doc/intro.9.txt b/doc/intro.9.txt index 4ea7a44b..4656a425 100644 --- a/doc/intro.9.txt +++ b/doc/intro.9.txt @@ -175,17 +175,20 @@ TODO Write when the virtual memory system is rewritten. REAL-TIME --------- -X15 complies with several requirements of a true hard real-time multiprocessor -system. It is a fully preemptible kernel with short, bounded preemption-based -critical sections. It provides real-time scheduling policies and a complete -priority inheritance algorithm. Preemption and interrupts are clearly -decoupled so that interrupts can remain enabled as much as possible. The -modules related to real-time are : +X15 complies with almost all the requirements of a true hard real-time +multiprocessor system. It is a fully preemptible kernel with short, +bounded preemption-based critical sections. It provides real-time +scheduling policies and a complete priority inheritance algorithm. +Preemption and interrupts are clearly decoupled so that interrupts +can remain enabled as much as possible. Multiprocessor synchronization +uses rigorously fair spin locks. The modules related to real-time are : module:arch/trap:: Interrupt and exception handling. module:kern/rtmutex:: Mutual exclusion with priority inheritance. +module:kern/spinlock:: + Inter-processor spin locks. module:kern/thread:: Preemptive thread scheduling. module:kern/turnstile:: @@ -196,10 +199,7 @@ Victor Yodaiken's report {against-priority-inheritance} in order to fully understand the implications of relying on priority inheritance. TODO X15 doesn't yet comply with all the requirements for hard real-time. -For that, it still needs : - -* Time-bounded spin locks. -* Timer service. +For that, it still needs a high resolution timer system. [[portability]] PORTABILITY |