[patch 00/55] genirq: Debuggability, consolidation and managed affinities

[Thomas Gleixner]

This started out with 5 patches from Christoph who wanted to add a
mechanism for interrupts with managed affinities to spread them over all
present CPUs and instead of migrating them, shut them down into managed
shutdown state when the last CPU in the affinity set goes offline and then
resume them when a CPU to which belongs to the affinity set comes online
again. See:

   http://lkml.kernel.org/r/20170603140403.27379-1-hch@xxxxxx

After staring at it for a while it became clear that the approach is not
sufficient to deal with all the oddities of the x86 interrupt handling.

The mechanism to migrate interrupts inside the affinity set or shut them
down when the last CPU of the set goes offline is the same as the general
cpu hotplug migration mechanism. x86 does not use yet the generic cpu
hotplug irq migration code, so supporting this feature would require
changes to both architecture and core code. After staring long enough, I
decided to extend the core migration code so it can handle the x86 oddities
as well. There are a few subtle changes in that code which might affect the
existing users (ARM64/POWERPC), but AFAICT they should not change the
behaviour. Please look carefully.

While doing this I stumbled over a bunch of other details, which I
addressed in seperate patches. Once again the missing ability to debug all
of this turned out to be a major pain. So I hacked a quick debugfs tool,
which helped me to sort out the details. I rewrote that proper and it's
included in the start of the series. This also required to extend the
fwnode so x86 can supply unique domain names on domain creation.

The series applies on

    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core

and is also available via git from:

    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.irq


Thanks,

	tglx

----
 arch/x86/Kconfig                      |    2 
 arch/x86/include/asm/apic.h           |   36 +----
 arch/x86/include/asm/irq.h            |    1 
 arch/x86/include/asm/irq_remapping.h  |    3 
 arch/x86/kernel/apic/apic.c           |   35 +++--
 arch/x86/kernel/apic/apic_flat_64.c   |    4 
 arch/x86/kernel/apic/apic_noop.c      |    2 
 arch/x86/kernel/apic/apic_numachip.c  |    4 
 arch/x86/kernel/apic/bigsmp_32.c      |    2 
 arch/x86/kernel/apic/htirq.c          |   21 ++-
 arch/x86/kernel/apic/io_apic.c        |   22 +++
 arch/x86/kernel/apic/msi.c            |   55 ++++++--
 arch/x86/kernel/apic/probe_32.c       |    2 
 arch/x86/kernel/apic/vector.c         |   49 +++++--
 arch/x86/kernel/apic/x2apic_cluster.c |   36 ++---
 arch/x86/kernel/apic/x2apic_phys.c    |    2 
 arch/x86/kernel/apic/x2apic_uv_x.c    |   26 +---
 arch/x86/kernel/irq.c                 |   78 ------------
 arch/x86/platform/uv/uv_irq.c         |   18 ++
 arch/x86/xen/apic.c                   |    2 
 drivers/iommu/amd_iommu.c             |   22 ++-
 drivers/iommu/intel_irq_remapping.c   |   31 +++-
 drivers/pci/host/vmd.c                |    8 +
 drivers/xen/events/events_base.c      |    6 
 include/linux/cpuhotplug.h            |    1 
 include/linux/irq.h                   |   61 +++++++++
 include/linux/irqdesc.h               |    4 
 include/linux/irqdomain.h             |   37 +++++
 kernel/cpu.c                          |    5 
 kernel/irq/Kconfig                    |   15 ++
 kernel/irq/Makefile                   |    1 
 kernel/irq/affinity.c                 |   76 +++++++++--
 kernel/irq/autoprobe.c                |    4 
 kernel/irq/chip.c                     |   91 ++++++++++++--
 kernel/irq/cpuhotplug.c               |  150 +++++++++++++++++++----
 kernel/irq/debugfs.c                  |  220 ++++++++++++++++++++++++++++++++++
 kernel/irq/internals.h                |  100 +++++++++++++++
 kernel/irq/irqdesc.c                  |   30 +++-
 kernel/irq/irqdomain.c                |  170 ++++++++++++++++++++++++--
 kernel/irq/manage.c                   |  102 ++++-----------
 kernel/irq/migration.c                |   30 ++++
 kernel/irq/msi.c                      |    3 
 kernel/irq/proc.c                     |  110 ++++++++++++++---
 43 files changed, 1294 insertions(+), 383 deletions(-)