Commit-ID: f7fa7aeeecb7a9abdd5f5d069a71ffb3e99a2a07
Gitweb: http://git.kernel.org/tip/f7fa7aeeecb7a9abdd5f5d069a71ffb3e99a2a07
Author: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
AuthorDate: Tue, 14 Apr 2015 10:30:10 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 24 Apr 2015 15:36:55 +0200
x86/irq: Avoid memory allocation in __assign_irq_vector()
Function __assign_irq_vector() is protected by vector_lock, so use
a global temporary cpu_mask to avoid allocating/freeing cpu_mask.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
Cc: Sander Eikelenboom <linux@xxxxxxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Link: http://lkml.kernel.org/r/1428978610-28986-34-git-send-email-jiang.liu@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/apic/vector.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index ad786f8..1c7dd42 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -30,6 +30,7 @@ struct apic_chip_data {
struct irq_domain *x86_vector_domain;
static DEFINE_RAW_SPINLOCK(vector_lock);
+static cpumask_var_t vector_cpumask;
static struct irq_chip lapic_controller;
#ifdef CONFIG_X86_IO_APIC
static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
@@ -116,14 +117,10 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d,
static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
static int current_offset = VECTOR_OFFSET_START % 16;
int cpu, err;
- cpumask_var_t tmp_mask;
if (d->move_in_progress)
return -EBUSY;
- if (!alloc_cpumask_var(&tmp_mask, GFP_ATOMIC))
- return -ENOMEM;
-
/* Only try and allocate irqs on cpus that are present */
err = -ENOSPC;
cpumask_clear(d->old_domain);
@@ -131,21 +128,22 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d,
while (cpu < nr_cpu_ids) {
int new_cpu, vector, offset;
- apic->vector_allocation_domain(cpu, tmp_mask, mask);
+ apic->vector_allocation_domain(cpu, vector_cpumask, mask);
- if (cpumask_subset(tmp_mask, d->domain)) {
+ if (cpumask_subset(vector_cpumask, d->domain)) {
err = 0;
- if (cpumask_equal(tmp_mask, d->domain))
+ if (cpumask_equal(vector_cpumask, d->domain))
break;
/*
* New cpumask using the vector is a proper subset of
* the current in use mask. So cleanup the vector
* allocation for the members that are not used anymore.
*/
- cpumask_andnot(d->old_domain, d->domain, tmp_mask);
+ cpumask_andnot(d->old_domain, d->domain,
+ vector_cpumask);
d->move_in_progress =
cpumask_intersects(d->old_domain, cpu_online_mask);
- cpumask_and(d->domain, d->domain, tmp_mask);
+ cpumask_and(d->domain, d->domain, vector_cpumask);
break;
}
@@ -159,16 +157,18 @@ next:
}
if (unlikely(current_vector == vector)) {
- cpumask_or(d->old_domain, d->old_domain, tmp_mask);
- cpumask_andnot(tmp_mask, mask, d->old_domain);
- cpu = cpumask_first_and(tmp_mask, cpu_online_mask);
+ cpumask_or(d->old_domain, d->old_domain,
+ vector_cpumask);
+ cpumask_andnot(vector_cpumask, mask, d->old_domain);
+ cpu = cpumask_first_and(vector_cpumask,
+ cpu_online_mask);
continue;
}
if (test_bit(vector, used_vectors))
goto next;
- for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask) {
+ for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask) {
if (per_cpu(vector_irq, new_cpu)[vector] >
VECTOR_UNDEFINED)
goto next;
@@ -181,14 +181,13 @@ next:
d->move_in_progress =
cpumask_intersects(d->old_domain, cpu_online_mask);
}
- for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask)
+ for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask)
per_cpu(vector_irq, new_cpu)[vector] = irq;
d->cfg.vector = vector;
- cpumask_copy(d->domain, tmp_mask);
+ cpumask_copy(d->domain, vector_cpumask);
err = 0;
break;
}
- free_cpumask_var(tmp_mask);
if (!err) {
/* cache destination APIC IDs into cfg->dest_apicid */
@@ -397,6 +396,8 @@ int __init arch_early_irq_init(void)
arch_init_msi_domain(x86_vector_domain);
arch_init_htirq_domain(x86_vector_domain);
+ BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
+
return arch_early_ioapic_init();
}
--
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