2014-01-24 20:10:51

by Yinghai Lu

[permalink] [raw]
Subject: [PATCH] x86: allocate cpumask during check irq vectors

Fix warning:
arch/x86/kernel/irq.c: In function check_irq_vectors_for_cpu_disable:
arch/x86/kernel/irq.c:337:1: warning: the frame size of 2052 bytes is larger than 2048 bytes

when NR_CPUS=8192

We should use zalloc_cpumask_var() instead.

Signed-off-by: Yinghai Lu <[email protected]>
Cc: Prarit Bhargava <[email protected]>

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index dbb6087..b114ee4 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -277,11 +277,14 @@ int check_irq_vectors_for_cpu_disable(void)
unsigned int this_cpu, vector, this_count, count;
struct irq_desc *desc;
struct irq_data *data;
- struct cpumask affinity_new, online_new;
+ cpumask_var_t affinity_new, online_new;
+
+ zalloc_cpumask_var(&affinity_new, GFP_KERNEL);
+ zalloc_cpumask_var(&online_new, GFP_KERNEL);

this_cpu = smp_processor_id();
- cpumask_copy(&online_new, cpu_online_mask);
- cpu_clear(this_cpu, online_new);
+ cpumask_copy(online_new, cpu_online_mask);
+ cpumask_clear_cpu(this_cpu, online_new);

this_count = 0;
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
@@ -289,8 +292,8 @@ int check_irq_vectors_for_cpu_disable(void)
if (irq >= 0) {
desc = irq_to_desc(irq);
data = irq_desc_get_irq_data(desc);
- cpumask_copy(&affinity_new, data->affinity);
- cpu_clear(this_cpu, affinity_new);
+ cpumask_copy(affinity_new, data->affinity);
+ cpumask_clear_cpu(this_cpu, affinity_new);

/* Do not count inactive or per-cpu irqs. */
if (!irq_has_action(irq) || irqd_is_per_cpu(data))
@@ -311,8 +314,8 @@ int check_irq_vectors_for_cpu_disable(void)
* mask is not zero; that is the down'd cpu is the
* last online cpu in a user set affinity mask.
*/
- if (cpumask_empty(&affinity_new) ||
- !cpumask_subset(&affinity_new, &online_new))
+ if (cpumask_empty(affinity_new) ||
+ !cpumask_subset(affinity_new, online_new))
this_count++;
}
}


2014-01-25 02:26:41

by Chen, Gong

[permalink] [raw]
Subject: Re: [PATCH] x86: allocate cpumask during check irq vectors

On Fri, Jan 24, 2014 at 12:11:07PM -0800, Yinghai Lu wrote:
> Date: Fri, 24 Jan 2014 12:11:07 -0800
> From: Yinghai Lu <[email protected]>
> To: "H. Peter Anvin" <[email protected]>
> Cc: Thomas Gleixner <[email protected]>, Ingo Molnar <[email protected]>,
> [email protected], Yinghai Lu <[email protected]>, Prarit
> Bhargava <[email protected]>
> Subject: [PATCH] x86: allocate cpumask during check irq vectors
> X-Mailer: git-send-email 1.8.4
>
> Fix warning:
> arch/x86/kernel/irq.c: In function check_irq_vectors_for_cpu_disable:
> arch/x86/kernel/irq.c:337:1: warning: the frame size of 2052 bytes is larger than 2048 bytes
>
> when NR_CPUS=8192
>
> We should use zalloc_cpumask_var() instead.
>
> Signed-off-by: Yinghai Lu <[email protected]>
> Cc: Prarit Bhargava <[email protected]>
>
> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
> index dbb6087..b114ee4 100644
> --- a/arch/x86/kernel/irq.c
> +++ b/arch/x86/kernel/irq.c
> @@ -277,11 +277,14 @@ int check_irq_vectors_for_cpu_disable(void)
> unsigned int this_cpu, vector, this_count, count;
> struct irq_desc *desc;
> struct irq_data *data;
> - struct cpumask affinity_new, online_new;
> + cpumask_var_t affinity_new, online_new;
> +
> + zalloc_cpumask_var(&affinity_new, GFP_KERNEL);
> + zalloc_cpumask_var(&online_new, GFP_KERNEL);
>
Hi, Yinghai

The original author Prarit Bhargava had committed a similar
patch and I ever said this function is protected by stop_machine
so GFP_KERNEL is not reliable. It should be GFP_ATOMIC.


Attachments:
(No filename) (1.50 kB)
signature.asc (836.00 B)
Digital signature
Download all attachments