linux/kernel/irq
Keith Busch 7bf8222b9b irq/affinity: Fix CPU spread for unbalanced nodes
The irq_create_affinity_masks routine is responsible for assigning a
number of interrupt vectors to CPUs. The optimal assignemnet will spread
requested vectors to all CPUs, with the fewest CPUs sharing a vector.

The algorithm may fail to assign some vectors to any CPUs if a node's
CPU count is lower than the average number of vectors per node. These
vectors are unusable and create an un-optimal spread.

Recalculate the number of vectors to assign at each node iteration by using
the remaining number of vectors and nodes to be assigned, not exceeding the
number of CPUs in that node. This will guarantee that every CPU is assigned
at least one vector.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/1491247553-7603-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-04 11:57:28 +02:00
..
affinity.c irq/affinity: Fix CPU spread for unbalanced nodes 2017-04-04 11:57:28 +02:00
autoprobe.c
chip.c genirq: Make function __irq_do_set_handler() static 2016-09-25 16:46:52 -04:00
cpuhotplug.c genirq: Make the cpuhotplug migration code less noisy 2015-10-22 14:34:57 +02:00
debug.h
devres.c genirq/devres: Use dev_name(dev) as default for devname 2017-02-12 19:49:25 +01:00
dummychip.c Merge branch 'linus' into irq/core 2015-06-05 22:25:01 +02:00
generic-chip.c genirq/generic_chip: Verify irqs_per_chip <= 32 2016-09-02 20:20:59 +02:00
handle.c genirq: Add untracked irq handler 2016-06-18 10:00:55 +02:00
internals.h Merge branch 'irq/for-block' into irq/core 2016-07-04 12:26:05 +02:00
ipi.c genirq: Fix missing irq allocation affinity hint 2016-07-19 10:49:47 +02:00
irqdesc.c Merge branch 'irq/for-block' into irq/core 2016-09-15 20:54:40 +02:00
irqdomain.c Merge branches 'iommu/fixes', 'arm/exynos', 'arm/renesas', 'arm/smmu', 'arm/mediatek', 'arm/core', 'x86/vt-d' and 'core' into next 2017-02-10 15:13:10 +01:00
Kconfig genirq: Add GENERIC_IRQ_IPI Kconfig symbol 2016-02-25 10:56:55 +01:00
Makefile genirq: Add a helper to spread an affinity mask for MSI/MSI-X vectors 2016-07-04 12:25:14 +02:00
manage.c sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:40 +01:00
migration.c genirq: Remove bogus restriction in irq_move_mask_irq() 2015-06-20 19:05:14 +02:00
msi.c genirq/msi: Set IRQ_DOMAIN_FLAG_MSI on MSI domain creation 2017-01-23 15:00:45 +00:00
pm.c Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-15 09:30:48 -08:00
proc.c genirq: Fix /proc/interrupts output alignment 2017-02-10 20:17:52 +01:00
resend.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
settings.h genirq: Add flag to force mask in disable_irq[_nosync]() 2015-10-11 11:33:42 +02:00
spurious.c genirq: Clarify logic calculating bogus irqreturn_t values 2017-02-16 15:32:19 +01:00