xv6

commit ab4cedb5930cb21f0a4810f64be0ab6cfca026f3
parent ef2185247d468309a375b0e16d73e8723cdf29a0
Author: rtm <rtm>
Date:   Fri, 31 Aug 2007 19:55:27 +0000

continuous quality management

Diffstat:
M
asm.h
 | 
2
+-
M
spinlock.c
 | 
4
++--
M
x86.h
 | 
6
+++---

3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/asm.h b/asm.h
@@ -1,5 +1,5 @@
 //
-// macros to create x86 segments from assembler
+// assembler macros to create x86 segments
 //
 
 #define SEG_NULLASM                                             \
diff --git a/spinlock.c b/spinlock.c
@@ -20,8 +20,8 @@ initlock(struct spinlock *lock, char *name)
 
 // Acquire the lock.
 // Loops (spins) until the lock is acquired.
-// (Because contention is handled by spinning,
-// must not go to sleep holding any locks.)
+// Holding a lock for a long time may cause
+// other CPUs to waste time spinning to acquire it.
 void
 acquire(struct spinlock *lock)
 {
diff --git a/x86.h b/x86.h
@@ -1,5 +1,4 @@
-// Special assembly routines to access x86-specific
-// hardware instructions.
+// Routines to let C code use special x86 instructions.
 
 static inline uchar
 inb(ushort port)
@@ -131,7 +130,8 @@ sti(void)
   asm volatile("sti");
 }
 
-// Layout of the trap frame on the stack upon entry to trap.
+// Layout of the trap frame built on the stack by the
+// hardware and by trapasm.S, and passed to trap().
 struct trapframe {
   // registers as pushed by pusha
   uint edi;