Re: [PATCH] cpumask: alloc blank cpumask left over

Rusty Russell
2009-06-05T13:43:05Z

On Fri, 5 Jun 2009 03:26:57 pm Yinghai Lu wrote:
> Rusty Russell wrote:
> > On Fri, 5 Jun 2009 06:31:31 am Yinghai Lu wrote:
> >> avoid suprise when MAXSMP is enabled
> >>
> >> Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
> >
> > I understand the temptation, but two questions arise:
> > 1) Shouldn't we actually audit to see if any of these are currently
> > problems,
>
> those are defined as static cpumask_var_t, and if MAXSMP is not used, they
> are cleared already

OK, here's what I've got in my tree. Ingo, I think this should go in the
current -rc to avoid nasty bugs.

BTW, the original alloc_cpumask_var did zero; that was dropped after arguments
over efficiency and fitting with other interfaces, but I clearly had the old
semantics in my head for a while.

Thanks,
Rusty.

Subject: cpumask: alloc zeroed cpumask for static cpumask_var_ts
Date: Thu, 04 Jun 2009 14:01:31 -0700
From: Yinghai Lu <yinghai@kernel.org>

These are defined as static cpumask_var_t so if MAXSMP is not used,
they are cleared already. Avoid suprises when MAXSMP is enabled.

Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 2 +-
arch/x86/kernel/cpu/cpufreq/powernow-k7.c | 2 +-
arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 3 ++-
arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c | 3 ++-
arch/x86/kernel/cpu/mcheck/mce_64.c | 2 +-
arch/x86/kernel/tlb_uv.c | 3 ++-
drivers/acpi/processor_core.c | 3 ++-
drivers/cpufreq/cpufreq.c | 3 ++-
kernel/sched_cpupri.c | 2 +-
kernel/sched_rt.c | 3 ++-
kernel/smp.c | 5 +++--
11 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -552,7 +552,7 @@ static int __init acpi_cpufreq_early_ini
for_each_possible_cpu(i) {
if (!alloc_cpumask_var_node(
&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
- GFP_KERNEL, cpu_to_node(i))) {
+ GFP_KERNEL | __GFP_ZERO, cpu_to_node(i))) {

/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
free_acpi_perf_data();
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k7.c b/arch/x86/kernel/cpu/cpufreq/powernow-k7.c
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k7.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k7.c
@@ -323,7 +323,7 @@ static int powernow_acpi_init(void)
}

if (!alloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
- GFP_KERNEL)) {
+ GFP_KERNEL | __GFP_ZERO)) {
retval = -ENOMEM;
goto err05;
}
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -886,7 +886,8 @@ static int powernow_k8_cpu_init_acpi(str
/* notify BIOS that we exist */
acpi_processor_notify_smm(THIS_MODULE);

- if (!alloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
+ if (!alloc_cpumask_var(&data->acpi_data.shared_cpu_map,
+ GFP_KERNEL | __GFP_ZERO)) {
printk(KERN_ERR PFX
"unable to alloc powernow_k8_data cpumask\n");
ret_val = -ENOMEM;
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -471,7 +471,8 @@ static int centrino_target (struct cpufr

if (unlikely(!alloc_cpumask_var(&saved_mask, GFP_KERNEL)))
return -ENOMEM;
- if (unlikely(!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))) {
+ if (unlikely(!alloc_cpumask_var(&covered_cpus,
+ GFP_KERNEL | __GFP_ZERO))) {
free_cpumask_var(saved_mask);
return -ENOMEM;
}
diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c
--- a/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -1163,7 +1163,7 @@ static __init int mce_init_device(void)
if (!mce_available(&boot_cpu_data))
return -EIO;

- alloc_cpumask_var(&mce_device_initialized, GFP_KERNEL);
+ alloc_cpumask_var(&mce_device_initialized, GFP_KERNEL | __GFP_ZERO);

err = mce_init_banks();
if (err)
diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -833,7 +833,8 @@ static int __init uv_bau_init(void)

for_each_possible_cpu(cur_cpu)
alloc_cpumask_var_node(&per_cpu(uv_flush_tlb_mask, cur_cpu),
- GFP_KERNEL, cpu_to_node(cur_cpu));
+ GFP_KERNEL | __GFP_ZERO,
+ cpu_to_node(cur_cpu));

uv_bau_retry_limit = 1;
uv_nshift = uv_hub_info->n_val;
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -844,7 +844,8 @@ static int acpi_processor_add(struct acp
if (!pr)
return -ENOMEM;

- if (!alloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
+ if (!alloc_cpumask_var(&pr->throttling.shared_cpu_map,
+ GFP_KERNEL | __GFP_ZERO)) {
kfree(pr);
return -ENOMEM;
}
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -808,7 +808,8 @@ static int cpufreq_add_dev(struct sys_de
ret = -ENOMEM;
goto nomem_out;
}
- if (!alloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) {
+ if (!alloc_cpumask_var(&policy->related_cpus,
+ GFP_KERNEL | __GFP_ZERO)) {
free_cpumask_var(policy->cpus);
kfree(policy);
ret = -ENOMEM;
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -165,7 +165,7 @@ int __init_refok cpupri_init(struct cpup
vec->count = 0;
if (bootmem)
alloc_bootmem_cpumask_var(&vec->mask);
- else if (!alloc_cpumask_var(&vec->mask, GFP_KERNEL))
+ else if (!alloc_cpumask_var(&vec->mask, GFP_KERNEL | __GFP_ZERO))
goto cleanup;
}

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1592,7 +1592,8 @@ static inline void init_sched_rt_class(v

for_each_possible_cpu(i)
alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
- GFP_KERNEL, cpu_to_node(i));
+ GFP_KERNEL | __GFP_ZERO,
+ cpu_to_node(i));
}
#endif /* CONFIG_SMP */

diff --git a/kernel/smp.c b/kernel/smp.c
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -52,8 +52,9 @@ hotplug_cfd(struct notifier_block *nfb,
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (!alloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
- cpu_to_node(cpu)))
+ if (!alloc_cpumask_var_node(&cfd->cpumask,
+ GFP_KERNEL | __GFP_ZERO,
+ cpu_to_node(cpu)))
return NOTIFY_BAD;
break;