From 4e8f237be819424f922399f8d121d9867b675541 Mon Sep 17 00:00:00 2001
From: rtm <rtm>
Date: Wed, 12 Jul 2006 01:48:35 +0000
Subject: no more big kernel lock succeeds at usertests.c pipe test
---
spinlock.c | 61 ++++++++++++++++++++++++++++++-------------------------------
1 file changed, 30 insertions(+), 31 deletions(-)
(limited to 'spinlock.c')
diff --git a/spinlock.c b/spinlock.c
index d73faff..9f840a8 100644
--- a/spinlock.c
+++ b/spinlock.c
@@ -2,51 +2,50 @@
#include "defs.h"
#include "x86.h"
#include "mmu.h"
+#include "param.h"
+#include "proc.h"
+#include "spinlock.h"
-#define LOCK_FREE -1
#define DEBUG 0
-uint32_t kernel_lock = LOCK_FREE;
-
int getcallerpc(void *v) {
return ((int*)v)[-1];
}
-// lock = LOCK_FREE if free, else = cpu_id of owner CPU
void
-acquire_spinlock(uint32_t* lock)
+acquire(struct spinlock * lock)
{
- int cpu_id = cpu();
+ struct proc * cp = curproc[cpu()];
// on a real machine there would be a memory barrier here
- if(DEBUG) cprintf("cpu%d: acquiring at %x\n", cpu_id, getcallerpc(&lock));
- cli();
- if (*lock == cpu_id)
- panic("recursive lock");
-
- while ( cmpxchg(LOCK_FREE, cpu_id, lock) != cpu_id ) { ; }
- if(DEBUG) cprintf("cpu%d: acquired at %x\n", cpu_id, getcallerpc(&lock));
+ if(DEBUG) cprintf("cpu%d: acquiring at %x\n", cpu(), getcallerpc(&lock));
+ if (cp && lock->p == cp && lock->locked){
+ lock->count += 1;
+ } else {
+ cli();
+ while ( cmpxchg(0, 1, &lock->locked) != 1 ) { ; }
+ lock->locker_pc = getcallerpc(&lock);
+ lock->count = 1;
+ lock->p = cp;
+ }
+ if(DEBUG) cprintf("cpu%d: acquired at %x\n", cpu(), getcallerpc(&lock));
}
void
-release_spinlock(uint32_t* lock)
+release(struct spinlock * lock)
{
- int cpu_id = cpu();
- if(DEBUG) cprintf ("cpu%d: releasing at %x\n", cpu_id, getcallerpc(&lock));
- if (*lock != cpu_id)
- panic("release_spinlock: releasing a lock that i don't own\n");
- *lock = LOCK_FREE;
- // on a real machine there would be a memory barrier here
- sti();
-}
+ struct proc * cp = curproc[cpu()];
-void
-release_grant_spinlock(uint32_t* lock, int c)
-{
- int cpu_id = cpu();
- if(DEBUG) cprintf ("cpu%d: release_grant to %d at %x\n", cpu_id, c, getcallerpc(&lock));
- if (*lock != cpu_id)
- panic("release_spinlock: releasing a lock that i don't own\n");
- *lock = c;
-}
+ if(DEBUG) cprintf ("cpu%d: releasing at %x\n", cpu(), getcallerpc(&lock));
+ if(lock->p != cp || lock->count < 1 || lock->locked != 1)
+ panic("release");
+
+ lock->count -= 1;
+ if(lock->count < 1){
+ lock->p = 0;
+ cmpxchg(1, 0, &lock->locked);
+ sti();
+ // on a real machine there would be a memory barrier here
+ }
+}
--
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