linux/kernel/irq
Dou Liyang 76f99ae5b5 irq/matrix: Spread managed interrupts on allocation
Linux spreads out the non managed interrupt across the possible target CPUs
to avoid vector space exhaustion.

Managed interrupts are treated differently, as for them the vectors are
reserved (with guarantee) when the interrupt descriptors are initialized.

When the interrupt is requested a real vector is assigned. The assignment
logic uses the first CPU in the affinity mask for assignment. If the
interrupt has more than one CPU in the affinity mask, which happens when a
multi queue device has less queues than CPUs, then doing the same search as
for non managed interrupts makes sense as it puts the interrupt on the
least interrupt plagued CPU. For single CPU affine vectors that's obviously
a NOOP.

Restructre the matrix allocation code so it does the 'best CPU' search, add
the sanity check for an empty affinity mask and adapt the call site in the
x86 vector management code.

[ tglx: Added the empty mask check to the core and improved change log ]

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/20180908175838.14450-2-dou_liyang@163.com
2018-09-18 18:27:24 +02:00
..
Kconfig genirq/irqchip: Remove MULTI_IRQ_HANDLER as it's now obselete 2018-08-03 12:14:10 +02:00
Makefile Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:33:11 -08:00
affinity.c genirq/affinity: Spread irq vectors among present CPUs as far as possible 2018-04-06 12:19:51 +02:00
autoprobe.c genirq: Cleanup top of file comments 2018-03-20 14:23:27 +01:00
chip.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
cpuhotplug.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
debug.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
debugfs.c genirq/debugfs: Add missing IRQCHIP_SUPPORTS_LEVEL_MSI debug 2018-06-22 14:22:00 +02:00
devres.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
dummychip.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
generic-chip.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
handle.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
internals.h genirq: Make legacy autoprobing work again 2018-02-01 11:09:40 +01:00
ipi.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
irq_sim.c genirq/irq_sim: Remove the license boilerplate 2018-04-26 22:26:39 +02:00
irqdesc.c genirq: Use rcu in kstat_irqs_usr() 2018-06-19 09:19:40 +02:00
irqdomain.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
manage.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 10:47:26 -07:00
matrix.c irq/matrix: Spread managed interrupts on allocation 2018-09-18 18:27:24 +02:00
migration.c genirq/migration: Avoid out of line call if pending is not set 2018-06-06 15:18:20 +02:00
msi.c genirq/msi: Allow level-triggered MSIs to be exposed by MSI providers 2018-05-13 15:58:59 +02:00
pm.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
proc.c genirq: Speedup show_interrupts() 2018-06-22 14:22:58 +02:00
resend.c genirq: Cleanup top of file comments 2018-03-20 14:23:27 +01:00
settings.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spurious.c genirq: Cleanup top of file comments 2018-03-20 14:23:27 +01:00
timings.c genirq: Remove license boilerplate/references 2018-03-20 14:23:28 +01:00