diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2016-02-03 19:52:23 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-02-08 15:03:42 +0100 |
| commit | fbf198030e0b027538c290300cfaf9e2efdce122 (patch) | |
| tree | 54c1ab89d46ccd5a0da1e79b728e09085d5af415 | |
| parent | c7c42ec2baa1de7ab3965e4f1bf5073bee6065e4 (diff) | |
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>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | 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 551ecf09c8dd..87298f8592b7 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 0409da0bcc33..0ccd028817d7 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) |