Re: [LAU] limits.conf nice rtprio

On Fri, 2017-08-18 at 11:54 +0200, Jaromír Mikeš wrote:
> irqbalance should be disabled?

"Disabling the irqbalance daemon
This daemon is enabled by default and periodically forces interrupts to
be handled by CPUs in an even, fair manner. However in realtime
deployments, applications are typically dedicated and bound to specific
CPUs, so the irqbalance daemon is not required." - https://access.redhat
.com/documentation/en-
US/Red_Hat_Enterprise_MRG/1.3/html/Realtime_Tuning_Guide/sect-
Realtime_Tuning_Guide-General_System_Tuning-
Interrupt_and_Process_Binding.html
 

> I have different output for rtirq status with kernel as one is only PREEMPT not RT
> Seems to be that rtirq need RT kernel to work fully.

No, as already pointed out, if you should use a kernel without the rt
patch, you need to add "threadirqs" to the boot options.

For grub2's /boot/grub/grub.cfg it would probably look like this:

linux /boot/vmlinuz-foo root=bar 'ro' 'threadirqs'

I don't know where to add it for grub2's idiotic config for the config.

I'm using syslinux, so for /boot/syslinux/syslinux.cfg it definitively is:

APPEND root=bar ro threadirqs

> /etc/init.d/rtirq status
>
> PID CLS RTPRIO NI PRI %CPU STAT COMMAND
> 424 FF 90 - 130 0.0 S irq/31-snd_hda_
> 425 FF 85 - 125 6.0 S irq/19-ehci_hcd
> 429 FF 85 - 125 0.1 S irq/16-uhci_hcd
> 421 FF 84 - 124 0.0 S irq/23-ehci_hcd
> 431 FF 84 - 124 0.0 S irq/17-uhci_hcd
> 432 FF 83 - 123 0.0 S irq/18-uhci_hcd
> 420 FF 82 - 122 0.0 S irq/20-uhci_hcd
> 423 FF 81 - 121 0.0 S irq/21-uhci_hcd
> 66 FF 80 - 120 0.0 S irq/1-i8042
> 428 FF 80 - 120 0.0 S irq/22-uhci_hcd
> 65 FF 79 - 119 0.0 S irq/12-i8042
> 39 FF 50 - 90 0.0 S irq/9-acpi
> 57 FF 50 - 90 0.0 S irq/24-PCIe PME
> 58 FF 50 - 90 0.0 S irq/25-PCIe PME
> 59 FF 50 - 90 0.0 S irq/26-PCIe PME
> 60 FF 50 - 90 0.0 S irq/27-PCIe PME
> 61 FF 50 - 90 0.0 S irq/24-pciehp
> 62 FF 50 - 90 0.0 S irq/25-pciehp
> 63 FF 50 - 90 0.0 S irq/26-pciehp
> 64 FF 50 - 90 0.0 S irq/27-pciehp
> 67 FF 50 - 90 0.0 S irq/8-rtc0
> 105 FF 50 - 90 0.5 S irq/14-ata_piix
> 106 FF 50 - 90 0.0 S irq/15-ata_piix
> 408 FF 50 - 90 0.0 S irq/28-mei_me
> 409 FF 50 - 90 0.0 S irq/29-i915
> 418 FF 50 - 90 0.0 S irq/17-rtl_pci
> 419 FF 50 - 90 0.0 S irq/16-yenta
> 436 FF 50 - 90 0.0 S irq/23-i801_smb
> 610 FF 50 - 90 0.0 S irq/17-firewire
> 635 FF 50 - 90 0.0 S irq/18-mmc0
> 640 FF 50 - 90 0.0 S irq/18-r592
> 642 FF 50 - 90 0.0 S irq/18-r852
> 1061 FF 50 - 90 0.0 S irq/30-eth0
> 636 FF 49 - 89 0.0 S irq/18-s-mmc0
> 3 TS - 0 19 0.1 S ksoftirqd/0
> 22 TS - 0 19 0.1 S ksoftirqd/1

You are giving snd_hda_ the highest prio. Don't do it. It much likely is
an onboard device you aren't using for real-time audio.

You are giving i8042 real-time priority, don't give keyboard and mouse
this priority.

Simply edit /etc/conf.d/rtirq RTIRQ_NAME_LIST to:

RTIRQ_NAME_LIST="usb"

After that don't restart rtirq, restart the computer.

irq/16, irq/23, irq/17 and irq/18 share IRQs, so consider to use the
ehci (USB2) port using IRQ 19. Avoid using uhci (USB1) or the ehci
(USB2) port hat shares the IRQ.
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Received on Fri Aug 18 16:15:01 2017