Setup critical section management for parts that must not be interrupted.

1 files changed, 7 insertions, 8 deletions

diff --git a/src/kernel/include/idt.h b/src/kernel/include/idt.h
index 2cccfa5..45cc3e3 100644
--- a/src/kernel/include/idt.h
+++ b/src/kernel/include/idt.h
@@ -75,14 +75,13 @@ void idt_set_ex_handler(int number, isr_handler_t func);	//Set exception handler
 void idt_set_irq_handler(int number, isr_handler_t func);	//Set IRQ handler
 
 // Warning about IRQ handlers :
-// IRQ handlers must not call yield(), because that may not return ! Therefore they cannot
-// use mutexes, memory allocation and most usefull things. Basically the only thing they
-// can do is wake up another thread, so it is a good idea to have a thread that waits for
-// the IRQ and does something when it happens, and the IRQ handler only wakes up that thread
-// when the IRQ happens.
-// Remark on resume_thread : if the second argument is set to true, yield() is called in the
-// function, so it may never return in some circumstances
-// IRQ handlers are never preemptible
+// IRQ handlers may run on the kernel0 stack, which is reset each time the scheduler
+// is entered. Therefore IRQ handler routines may not call yield(), which makes them
+// unable to use mutexes, memory allocation and most usefull things. Basically the only
+// thing they can do is wake up another thread, so it is a good idea to have a thread
+// that waits for the IRQ and does something when it happens, and the IRQ handler only
+// wakes up that thread when the IRQ happens. They may also communicate via atomical
+// or lock free data structures.
 
 void dbg_dump_registers(registers_t*);