From: tip-bot for Thomas Gleixner <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, cl@linux.com, riel@redhat.com,
hpa@zytor.com, tglx@linutronix.de, bigeasy@linutronix.de,
mingo@kernel.org, peterz@infradead.org, fweisbec@gmail.com,
cmetcalf@ezchip.com
Subject: [tip:irq/core] genirq: Add default affinity mask command line option
Date: Mon, 8 Feb 2016 06:08:02 -0800 [thread overview]
Message-ID: <tip-fbf198030e0b027538c290300cfaf9e2efdce122@git.kernel.org> (raw)
In-Reply-To: <alpine.DEB.2.11.1602031948190.25254@nanos>
Commit-ID: fbf198030e0b027538c290300cfaf9e2efdce122
Gitweb: http://git.kernel.org/tip/fbf198030e0b027538c290300cfaf9e2efdce122
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Wed, 3 Feb 2016 19:52:23 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 8 Feb 2016 15:03:42 +0100
genirq: Add default affinity mask command line option
If we isolate CPUs, then we don't want random device interrupts on them. Even
w/o the user space irq balancer enabled we can end up with irqs on non boot
cpus and chasing newly requested interrupts is a tedious task.
Allow to restrict the default irq affinity mask.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
Documentation/kernel-parameters.txt | 9 +++++++++
kernel/irq/irqdesc.c | 21 +++++++++++++++++++--
2 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 551ecf0..87298f8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1687,6 +1687,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ip= [IP_PNP]
See Documentation/filesystems/nfs/nfsroot.txt.
+ irqaffinity= [SMP] Set the default irq affinity mask
+ Format:
+ <cpu number>,...,<cpu number>
+ or
+ <cpu number>-<cpu number>
+ (must be a positive range in ascending order)
+ or a mixture
+ <cpu number>,...,<cpu number>-<cpu number>
+
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0409da0..0ccd028 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -24,10 +24,27 @@
static struct lock_class_key irq_desc_lock_class;
#if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+ cpulist_parse(str, irq_default_affinity);
+ /*
+ * Set at least the boot cpu. We don't want to end up with
+ * bugreports caused by random comandline masks
+ */
+ cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+ return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
static void __init init_irq_default_affinity(void)
{
- alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
- cpumask_setall(irq_default_affinity);
+#ifdef CONFIG_CPUMASK_OFFSTACK
+ if (!irq_default_affinity)
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+#endif
+ if (cpumask_empty(irq_default_affinity))
+ cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
prev parent reply other threads:[~2016-02-08 14:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 18:52 [PATCH] genirq: Add default affinity mask command line option Thomas Gleixner
2016-02-03 19:12 ` Rik van Riel
2016-02-03 19:15 ` Thomas Gleixner
2016-02-08 10:50 ` [tip:irq/core] " tip-bot for Thomas Gleixner
2016-02-08 14:08 ` tip-bot for Thomas Gleixner [this message]
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