Subject: Re: [PATCH 0/2] powerpc/pseries: fix MSI/X IRQ affinity on pseries

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 24 Nov 2020 16:08:06 -0500

On Tue, Nov 24, 2020 at 09:03:06PM +0100, Laurent Vivier wrote:
> With virtio, in multiqueue case, each queue IRQ is normally
> bound to a different CPU using the affinity mask.
> 
> This works fine on x86_64 but totally ignored on pseries.
> 
> This is not obvious at first look because irqbalance is doing
> some balancing to improve that.
> 
> It appears that the "managed" flag set in the MSI entry
> is never copied to the system IRQ entry.
> 
> This series passes the affinity mask from rtas_setup_msi_irqs()
> to irq_domain_alloc_descs() by adding an affinity parameter to
> irq_create_mapping().
> 
> The first patch adds the parameter (no functional change), the
> second patch passes the actual affinity mask to irq_create_mapping()
> in rtas_setup_msi_irqs().
> 
> For instance, with 32 CPUs VM and 32 queues virtio-scsi interface:
> 
> ... -smp 32 -device virtio-scsi-pci,id=virtio_scsi_pci0,num_queues=32
> 
> for IRQ in $(grep virtio2-request /proc/interrupts |cut -d: -f1); do
>     for file in /proc/irq/$IRQ/ ; do
>         echo -n "IRQ: $(basename $file) CPU: " ; cat $file/smp_affinity_list
>     done
> done
> 
> Without the patch (and without irqbalanced)
> 
> IRQ: 268 CPU: 0-31
> IRQ: 269 CPU: 0-31
> IRQ: 270 CPU: 0-31
> IRQ: 271 CPU: 0-31
> IRQ: 272 CPU: 0-31
> IRQ: 273 CPU: 0-31
> IRQ: 274 CPU: 0-31
> IRQ: 275 CPU: 0-31
> IRQ: 276 CPU: 0-31
> IRQ: 277 CPU: 0-31
> IRQ: 278 CPU: 0-31
> IRQ: 279 CPU: 0-31
> IRQ: 280 CPU: 0-31
> IRQ: 281 CPU: 0-31
> IRQ: 282 CPU: 0-31
> IRQ: 283 CPU: 0-31
> IRQ: 284 CPU: 0-31
> IRQ: 285 CPU: 0-31
> IRQ: 286 CPU: 0-31
> IRQ: 287 CPU: 0-31
> IRQ: 288 CPU: 0-31
> IRQ: 289 CPU: 0-31
> IRQ: 290 CPU: 0-31
> IRQ: 291 CPU: 0-31
> IRQ: 292 CPU: 0-31
> IRQ: 293 CPU: 0-31
> IRQ: 294 CPU: 0-31
> IRQ: 295 CPU: 0-31
> IRQ: 296 CPU: 0-31
> IRQ: 297 CPU: 0-31
> IRQ: 298 CPU: 0-31
> IRQ: 299 CPU: 0-31
> 
> With the patch:
> 
> IRQ: 265 CPU: 0
> IRQ: 266 CPU: 1
> IRQ: 267 CPU: 2
> IRQ: 268 CPU: 3
> IRQ: 269 CPU: 4
> IRQ: 270 CPU: 5
> IRQ: 271 CPU: 6
> IRQ: 272 CPU: 7
> IRQ: 273 CPU: 8
> IRQ: 274 CPU: 9
> IRQ: 275 CPU: 10
> IRQ: 276 CPU: 11
> IRQ: 277 CPU: 12
> IRQ: 278 CPU: 13
> IRQ: 279 CPU: 14
> IRQ: 280 CPU: 15
> IRQ: 281 CPU: 16
> IRQ: 282 CPU: 17
> IRQ: 283 CPU: 18
> IRQ: 284 CPU: 19
> IRQ: 285 CPU: 20
> IRQ: 286 CPU: 21
> IRQ: 287 CPU: 22
> IRQ: 288 CPU: 23
> IRQ: 289 CPU: 24
> IRQ: 290 CPU: 25
> IRQ: 291 CPU: 26
> IRQ: 292 CPU: 27
> IRQ: 293 CPU: 28
> IRQ: 294 CPU: 29
> IRQ: 295 CPU: 30
> IRQ: 299 CPU: 31
> 
> This matches what we have on an x86_64 system.

Makes sense to me. FWIW

Acked-by: Michael S. Tsirkin <[email-masked]>

> Laurent Vivier (2):
>   genirq: add an affinity parameter to irq_create_mapping()
>   powerpc/pseries: pass MSI affinity to irq_create_mapping()
> 
>  arch/arc/kernel/intc-arcv2.c                  | 4 ++--
>  arch/arc/kernel/mcip.c                        | 2 +-
>  arch/arm/common/sa1111.c                      | 2 +-
>  arch/arm/mach-s3c/irq-s3c24xx.c               | 3 ++-
>  arch/arm/plat-orion/gpio.c                    | 2 +-
>  arch/mips/ath25/ar2315.c                      | 4 ++--
>  arch/mips/ath25/ar5312.c                      | 4 ++--
>  arch/mips/lantiq/irq.c                        | 2 +-
>  arch/mips/pci/pci-ar2315.c                    | 3 ++-
>  arch/mips/pic32/pic32mzda/time.c              | 2 +-
>  arch/mips/ralink/irq.c                        | 2 +-
>  arch/powerpc/kernel/pci-common.c              | 2 +-
>  arch/powerpc/kvm/book3s_xive.c                | 2 +-
>  arch/powerpc/platforms/44x/ppc476.c           | 4 ++--
>  arch/powerpc/platforms/cell/interrupt.c       | 4 ++--
>  arch/powerpc/platforms/cell/iommu.c           | 3 ++-
>  arch/powerpc/platforms/cell/pmu.c             | 2 +-
>  arch/powerpc/platforms/cell/spider-pic.c      | 2 +-
>  arch/powerpc/platforms/cell/spu_manage.c      | 6 +++---
>  arch/powerpc/platforms/maple/pci.c            | 2 +-
>  arch/powerpc/platforms/pasemi/dma_lib.c       | 5 +++--
>  arch/powerpc/platforms/pasemi/msi.c           | 2 +-
>  arch/powerpc/platforms/pasemi/setup.c         | 4 ++--
>  arch/powerpc/platforms/powermac/pci.c         | 2 +-
>  arch/powerpc/platforms/powermac/pic.c         | 2 +-
>  arch/powerpc/platforms/powermac/smp.c         | 2 +-
>  arch/powerpc/platforms/powernv/opal-irqchip.c | 5 +++--
>  arch/powerpc/platforms/powernv/pci.c          | 2 +-
>  arch/powerpc/platforms/powernv/vas.c          | 2 +-
>  arch/powerpc/platforms/ps3/interrupt.c        | 2 +-
>  arch/powerpc/platforms/pseries/ibmebus.c      | 2 +-
>  arch/powerpc/platforms/pseries/msi.c          | 2 +-
>  arch/powerpc/sysdev/fsl_mpic_err.c            | 2 +-
>  arch/powerpc/sysdev/fsl_msi.c                 | 2 +-
>  arch/powerpc/sysdev/mpic.c                    | 3 ++-
>  arch/powerpc/sysdev/mpic_u3msi.c              | 2 +-
>  arch/powerpc/sysdev/xics/xics-common.c        | 2 +-
>  arch/powerpc/sysdev/xive/common.c             | 2 +-
>  arch/sh/boards/mach-se/7343/irq.c             | 2 +-
>  arch/sh/boards/mach-se/7722/irq.c             | 2 +-
>  arch/sh/boards/mach-x3proto/gpio.c            | 2 +-
>  arch/xtensa/kernel/perf_event.c               | 2 +-
>  arch/xtensa/kernel/smp.c                      | 2 +-
>  arch/xtensa/kernel/time.c                     | 2 +-
>  drivers/ata/pata_macio.c                      | 2 +-
>  drivers/base/regmap/regmap-irq.c              | 2 +-
>  drivers/bus/moxtet.c                          | 2 +-
>  drivers/clocksource/ingenic-timer.c           | 2 +-
>  drivers/clocksource/timer-riscv.c             | 2 +-
>  drivers/extcon/extcon-max8997.c               | 3 ++-
>  drivers/gpio/gpio-bcm-kona.c                  | 2 +-
>  drivers/gpio/gpio-brcmstb.c                   | 2 +-
>  drivers/gpio/gpio-davinci.c                   | 2 +-
>  drivers/gpio/gpio-em.c                        | 3 ++-
>  drivers/gpio/gpio-grgpio.c                    | 2 +-
>  drivers/gpio/gpio-mockup.c                    | 2 +-
>  drivers/gpio/gpio-mpc8xxx.c                   | 2 +-
>  drivers/gpio/gpio-mvebu.c                     | 2 +-
>  drivers/gpio/gpio-tb10x.c                     | 2 +-
>  drivers/gpio/gpio-tegra.c                     | 2 +-
>  drivers/gpio/gpio-wm831x.c                    | 2 +-
>  drivers/gpio/gpiolib.c                        | 2 +-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c       | 3 ++-
>  drivers/gpu/ipu-v3/ipu-common.c               | 2 +-
>  drivers/hid/hid-rmi.c                         | 2 +-
>  drivers/i2c/busses/i2c-cht-wc.c               | 2 +-
>  drivers/i2c/i2c-core-base.c                   | 2 +-
>  drivers/i2c/muxes/i2c-mux-pca954x.c           | 2 +-
>  drivers/ide/pmac.c                            | 2 +-
>  drivers/iio/dummy/iio_dummy_evgen.c           | 3 ++-
>  drivers/input/rmi4/rmi_bus.c                  | 2 +-
>  drivers/irqchip/irq-ath79-misc.c              | 3 ++-
>  drivers/irqchip/irq-bcm2835.c                 | 3 ++-
>  drivers/irqchip/irq-csky-mpintc.c             | 2 +-
>  drivers/irqchip/irq-eznps.c                   | 2 +-
>  drivers/irqchip/irq-mips-gic.c                | 8 +++++---
>  drivers/irqchip/irq-mmp.c                     | 4 ++--
>  drivers/irqchip/irq-versatile-fpga.c          | 2 +-
>  drivers/irqchip/irq-vic.c                     | 2 +-
>  drivers/macintosh/macio_asic.c                | 2 +-
>  drivers/memory/omap-gpmc.c                    | 2 +-
>  drivers/mfd/ab8500-core.c                     | 2 +-
>  drivers/mfd/arizona-irq.c                     | 5 +++--
>  drivers/mfd/db8500-prcmu.c                    | 2 +-
>  drivers/mfd/mfd-core.c                        | 2 +-
>  drivers/mfd/stmpe.c                           | 5 +++--
>  drivers/mfd/tc3589x.c                         | 2 +-
>  drivers/mfd/tps6586x.c                        | 2 +-
>  drivers/mfd/wm8994-irq.c                      | 5 +++--
>  drivers/misc/cxl/irq.c                        | 2 +-
>  drivers/misc/ocxl/afu_irq.c                   | 2 +-
>  drivers/misc/ocxl/link.c                      | 2 +-
>  drivers/net/dsa/mv88e6xxx/chip.c              | 2 +-
>  drivers/net/dsa/mv88e6xxx/global2.c           | 2 +-
>  drivers/net/dsa/qca/ar9331.c                  | 2 +-
>  drivers/net/dsa/rtl8366rb.c                   | 3 ++-
>  drivers/net/ethernet/ibm/ibmvnic.c            | 4 ++--
>  drivers/net/usb/lan78xx.c                     | 2 +-
>  drivers/pci/controller/pci-ftpci100.c         | 2 +-
>  drivers/pci/controller/pci-tegra.c            | 2 +-
>  drivers/pci/controller/pcie-rcar-host.c       | 2 +-
>  drivers/pci/controller/pcie-xilinx-cpm.c      | 4 ++--
>  drivers/pci/controller/pcie-xilinx.c          | 2 +-
>  drivers/pinctrl/mediatek/mtk-eint.c           | 2 +-
>  drivers/pinctrl/nomadik/pinctrl-abx500.c      | 3 ++-
>  drivers/pinctrl/pinctrl-at91-pio4.c           | 3 ++-
>  drivers/pinctrl/pinctrl-rockchip.c            | 2 +-
>  drivers/pinctrl/samsung/pinctrl-samsung.c     | 2 +-
>  drivers/pinctrl/sunxi/pinctrl-sunxi.c         | 2 +-
>  drivers/power/supply/lp8788-charger.c         | 2 +-
>  drivers/rtc/rtc-lp8788.c                      | 2 +-
>  drivers/rtc/rtc-max8997.c                     | 3 ++-
>  drivers/rtc/rtc-max8998.c                     | 3 ++-
>  drivers/scsi/cxlflash/ocxl_hw.c               | 2 +-
>  drivers/ssb/driver_gpio.c                     | 4 ++--
>  drivers/staging/hikey9xx/hi6421-spmi-pmic.c   | 2 +-
>  drivers/staging/octeon-usb/octeon-hcd.c       | 2 +-
>  drivers/tty/hvc/hvsi.c                        | 2 +-
>  drivers/tty/serial/pmac_zilog.c               | 6 +++---
>  drivers/watchdog/octeon-wdt-main.c            | 2 +-
>  include/linux/irqdomain.h                     | 3 ++-
>  kernel/irq/irqdomain.c                        | 8 +++++---
>  sound/soc/codecs/rt5677.c                     | 2 +-
>  123 files changed, 171 insertions(+), 146 deletions(-)
> 
> -- 
> 2.28.0
>