summaryrefslogtreecommitdiff
path: root/trap.c
diff options
context:
space:
mode:
authorrsc <rsc>2007-08-27 13:34:35 +0000
committerrsc <rsc>2007-08-27 13:34:35 +0000
commitefc12b8e616ed3394468c1802da8e1f39e387cd3 (patch)
tree62340875e823c6784bde20077ccebd51cd5b4fe1 /trap.c
parente1872bb130da5a9b198ca484da8534304ea9fc79 (diff)
downloadxv6-labs-efc12b8e616ed3394468c1802da8e1f39e387cd3.tar.gz
xv6-labs-efc12b8e616ed3394468c1802da8e1f39e387cd3.tar.bz2
xv6-labs-efc12b8e616ed3394468c1802da8e1f39e387cd3.zip
Replace yield system call with sleep.
Diffstat (limited to 'trap.c')
-rw-r--r--trap.c42
1 files changed, 26 insertions, 16 deletions
diff --git a/trap.c b/trap.c
index 217e79d..e045aed 100644
--- a/trap.c
+++ b/trap.c
@@ -6,10 +6,13 @@
#include "x86.h"
#include "traps.h"
#include "syscall.h"
+#include "spinlock.h"
// Interrupt descriptor table (shared by all CPUs).
struct gatedesc idt[256];
extern uint vectors[]; // in vectors.S: array of 256 entry pointers
+struct spinlock tickslock;
+int ticks;
void
tvinit(void)
@@ -19,6 +22,8 @@ tvinit(void)
for(i = 0; i < 256; i++)
SETGATE(idt[i], 0, SEG_KCODE<<3, vectors[i], 0);
SETGATE(idt[T_SYSCALL], 0, SEG_KCODE<<3, vectors[T_SYSCALL], DPL_USER);
+
+ initlock(&tickslock, "time");
}
void
@@ -47,21 +52,14 @@ trap(struct trapframe *tf)
// PAGEBREAK: 10
switch(tf->trapno){
case IRQ_OFFSET + IRQ_TIMER:
- lapic_timerintr();
- cpus[cpu()].nlock--;
- if(cp){
- // Force process exit if it has been killed and is in user space.
- // (If it is still executing in the kernel, let it keep running
- // until it gets to the regular system call return.)
- if((tf->cs&3) == DPL_USER && cp->killed)
- proc_exit();
-
- // Force process to give up CPU and let others run.
- // If locks were held with interrupts on, would need to check nlock.
- if(cp->state == RUNNING)
- yield();
+ if(cpu() == 0){
+ acquire(&tickslock);
+ ticks++;
+ wakeup(&ticks);
+ release(&tickslock);
}
- return;
+ lapic_eoi();
+ break;
case IRQ_OFFSET + IRQ_IDE:
ide_intr();
@@ -75,6 +73,7 @@ trap(struct trapframe *tf)
case IRQ_OFFSET + IRQ_SPURIOUS:
cprintf("spurious interrupt from cpu %d eip %x\n", cpu(), tf->eip);
+ lapic_eoi();
break;
default:
@@ -84,12 +83,23 @@ trap(struct trapframe *tf)
cp->pid, cp->name, tf->trapno, tf->err, cpu(), tf->eip);
proc_exit();
}
-
// Otherwise it's our mistake.
cprintf("unexpected trap %d from cpu %d eip %x\n",
tf->trapno, cpu(), tf->eip);
panic("trap");
}
-
cpus[cpu()].nlock--;
+
+ if(tf->trapno == IRQ_OFFSET + IRQ_TIMER && cp != 0){
+ // Force process exit if it has been killed and is in user space.
+ // (If it is still executing in the kernel, let it keep running
+ // until it gets to the regular system call return.)
+ if((tf->cs&3) == DPL_USER && cp->killed)
+ proc_exit();
+
+ // Force process to give up CPU and let others run.
+ // If locks were held with interrupts on, would need to check nlock.
+ if(cp->state == RUNNING)
+ yield();
+ }
}