commit 664324745e2257289f7a61e43892ce6e8b8ed9b7
parent 4e8f237be819424f922399f8d121d9867b675541
Author: rtm <rtm>
Date: Wed, 12 Jul 2006 09:10:25 +0000
cvs add spinlock.h
fix race in schedule()
Diffstat:
4 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/Notes b/Notes
@@ -126,3 +126,10 @@ in general, the table locks protect both free-ness and
why can't i get a lock in console code?
always triple fault
lock code shouldn't call cprintf...
+ide_init doesn't work now?
+and IOAPIC: read from unsupported address
+ when running pre-empt user test
+ so maybe something wrong with clock interrupts
+ no! if one cpu holds lock w/ curproc0=,
+ then another cpu can take it, it looks like
+ a recursive acquire()
diff --git a/proc.c b/proc.c
@@ -148,7 +148,6 @@ scheduler(void)
if(i < NPROC){
np->state = RUNNING;
- release(&proc_table_lock);
break;
}
@@ -159,6 +158,8 @@ scheduler(void)
cpus[cpu()].lastproc = np;
curproc[cpu()] = np;
+ release(&proc_table_lock);
+
// h/w sets busy bit in TSS descriptor sometimes, and faults
// if it's set in LTR. so clear tss descriptor busy bit.
np->gdt[SEG_TSS].sd_type = STS_T32A;
diff --git a/spinlock.h b/spinlock.h
@@ -0,0 +1,6 @@
+struct spinlock {
+ unsigned int locked;
+ struct proc *p;
+ int count;
+ unsigned locker_pc;
+};
diff --git a/usertests.c b/usertests.c
@@ -93,8 +93,8 @@ preempt()
main()
{
puts("usertests starting\n");
- pipe1();
- //preempt();
+ //pipe1();
+ preempt();
while(1)
;