CPUFREQ: Fix two racing issues during cpu hotplug
Move cpufreq_del_cpu() call into __cpu_disable to eliminate racing with dbs
timer handler on policy & drv_data. Put it after local_irq_enable because
xmalloc/xfree in cpufreq_del_cpu assert for this.
Change access to cpufreq_statistic_lock from spin_lock to spin_lock_irqsave to
avoid statistic data access racing between cpufreq_statistic_exit and dbs timer
handler.
Signed-off-by: Wei Gang <gang.wei@xxxxxxxxx>
diff -r adce8bc43fcc xen/arch/x86/smpboot.c
--- a/xen/arch/x86/smpboot.c Tue Apr 06 07:16:47 2010 +0100
+++ b/xen/arch/x86/smpboot.c Fri Apr 09 11:54:42 2010 +0800
@@ -1293,6 +1293,7 @@ int __cpu_disable(void)
clear_local_APIC();
/* Allow any queued timer interrupts to get serviced */
local_irq_enable();
+ cpufreq_del_cpu(cpu);
mdelay(1);
local_irq_disable();
@@ -1362,8 +1363,6 @@ int cpu_down(unsigned int cpu)
}
printk("Prepare to bring CPU%d down...\n", cpu);
-
- cpufreq_del_cpu(cpu);
err = stop_machine_run(take_cpu_down, NULL, cpu);
if (err < 0)
diff -r adce8bc43fcc xen/drivers/acpi/pmstat.c
--- a/xen/drivers/acpi/pmstat.c Tue Apr 06 07:16:47 2010 +0100
+++ b/xen/drivers/acpi/pmstat.c Fri Apr 09 11:39:27 2010 +0800
@@ -86,15 +86,17 @@ int do_get_pm_info(struct xen_sysctl_get
case PMSTAT_get_pxstat:
{
uint32_t ct;
- struct pm_px *pxpt = cpufreq_statistic_data[op->cpuid];
+ struct pm_px *pxpt;
spinlock_t *cpufreq_statistic_lock =
&per_cpu(cpufreq_statistic_lock, op->cpuid);
-
- spin_lock(cpufreq_statistic_lock);
-
+ unsigned long flags;
+
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
+
+ pxpt = cpufreq_statistic_data[op->cpuid];
if ( !pxpt || !pxpt->u.pt || !pxpt->u.trans_pt )
{
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
return -ENODATA;
}
@@ -105,14 +107,14 @@ int do_get_pm_info(struct xen_sysctl_get
ct = pmpt->perf.state_count;
if ( copy_to_guest(op->u.getpx.trans_pt, pxpt->u.trans_pt, ct*ct) )
{
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
ret = -EFAULT;
break;
}
if ( copy_to_guest(op->u.getpx.pt, pxpt->u.pt, ct) )
{
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
ret = -EFAULT;
break;
}
@@ -122,7 +124,7 @@ int do_get_pm_info(struct xen_sysctl_get
op->u.getpx.last = pxpt->u.last;
op->u.getpx.cur = pxpt->u.cur;
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
break;
}
diff -r adce8bc43fcc xen/drivers/cpufreq/utility.c
--- a/xen/drivers/cpufreq/utility.c Tue Apr 06 07:16:47 2010 +0100
+++ b/xen/drivers/cpufreq/utility.c Fri Apr 09 11:39:27 2010 +0800
@@ -67,12 +67,13 @@ void cpufreq_statistic_update(unsigned i
struct processor_pminfo *pmpt = processor_pminfo[cpu];
spinlock_t *cpufreq_statistic_lock =
&per_cpu(cpufreq_statistic_lock, cpu);
-
- spin_lock(cpufreq_statistic_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
pxpt = cpufreq_statistic_data[cpu];
if ( !pxpt || !pmpt ) {
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
return;
}
@@ -84,7 +85,7 @@ void cpufreq_statistic_update(unsigned i
(*(pxpt->u.trans_pt + from * pmpt->perf.state_count + to))++;
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
}
int cpufreq_statistic_init(unsigned int cpuid)
@@ -94,15 +95,16 @@ int cpufreq_statistic_init(unsigned int
const struct processor_pminfo *pmpt = processor_pminfo[cpuid];
spinlock_t *cpufreq_statistic_lock =
&per_cpu(cpufreq_statistic_lock, cpuid);
+ unsigned long flags;
if ( !pmpt )
return -EINVAL;
- spin_lock(cpufreq_statistic_lock);
-
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
pxpt = cpufreq_statistic_data[cpuid];
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
+
if ( pxpt ) {
- spin_unlock(cpufreq_statistic_lock);
return 0;
}
@@ -110,16 +112,13 @@ int cpufreq_statistic_init(unsigned int
pxpt = xmalloc(struct pm_px);
if ( !pxpt ) {
- spin_unlock(cpufreq_statistic_lock);
return -ENOMEM;
}
memset(pxpt, 0, sizeof(*pxpt));
- cpufreq_statistic_data[cpuid] = pxpt;
pxpt->u.trans_pt = xmalloc_array(uint64_t, count * count);
if (!pxpt->u.trans_pt) {
xfree(pxpt);
- spin_unlock(cpufreq_statistic_lock);
return -ENOMEM;
}
@@ -127,7 +126,6 @@ int cpufreq_statistic_init(unsigned int
if (!pxpt->u.pt) {
xfree(pxpt->u.trans_pt);
xfree(pxpt);
- spin_unlock(cpufreq_statistic_lock);
return -ENOMEM;
}
@@ -143,8 +141,18 @@ int cpufreq_statistic_init(unsigned int
pxpt->prev_state_wall = NOW();
pxpt->prev_idle_wall = get_cpu_idle_time(cpuid);
- spin_unlock(cpufreq_statistic_lock);
-
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
+ if ( !cpufreq_statistic_data[cpuid] ) {
+ cpufreq_statistic_data[cpuid] = pxpt;
+ pxpt = NULL;
+ }
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
+
+ if (pxpt) {
+ xfree(pxpt->u.trans_pt);
+ xfree(pxpt->u.pt);
+ xfree(pxpt);
+ }
return 0;
}
@@ -153,21 +161,18 @@ void cpufreq_statistic_exit(unsigned int
struct pm_px *pxpt;
spinlock_t *cpufreq_statistic_lock =
&per_cpu(cpufreq_statistic_lock, cpuid);
-
- spin_lock(cpufreq_statistic_lock);
-
+ unsigned long flags;
+
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
pxpt = cpufreq_statistic_data[cpuid];
- if (!pxpt) {
- spin_unlock(cpufreq_statistic_lock);
- return;
- }
-
- xfree(pxpt->u.trans_pt);
- xfree(pxpt->u.pt);
- xfree(pxpt);
cpufreq_statistic_data[cpuid] = NULL;
-
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
+
+ if (pxpt) {
+ xfree(pxpt->u.trans_pt);
+ xfree(pxpt->u.pt);
+ xfree(pxpt);
+ }
}
void cpufreq_statistic_reset(unsigned int cpuid)
@@ -177,12 +182,13 @@ void cpufreq_statistic_reset(unsigned in
const struct processor_pminfo *pmpt = processor_pminfo[cpuid];
spinlock_t *cpufreq_statistic_lock =
&per_cpu(cpufreq_statistic_lock, cpuid);
-
- spin_lock(cpufreq_statistic_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(cpufreq_statistic_lock, flags);
pxpt = cpufreq_statistic_data[cpuid];
if ( !pmpt || !pxpt || !pxpt->u.pt || !pxpt->u.trans_pt ) {
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
return;
}
@@ -199,7 +205,7 @@ void cpufreq_statistic_reset(unsigned in
pxpt->prev_state_wall = NOW();
pxpt->prev_idle_wall = get_cpu_idle_time(cpuid);
- spin_unlock(cpufreq_statistic_lock);
+ spin_unlock_irqrestore(cpufreq_statistic_lock, flags);
}
dbs-timer-fix.patch
Description: dbs-timer-fix.patch
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