RE: [patch 1/1] Proposed: Let's not waste precious IRQs...
From: Protasevich, Natalie
Date: Fri May 20 2005 - 11:37:24 EST
>
> Hi Natalie,
>
> have you taken a look a the Vector Sharing Patch posted by
> Kaneshige for IA64?
>
> Cheers,
> ashok
Ashok,
I did initial testing of Zwane's IA-32 vector sharing patch, which
worked beautifully for the test case I mentioned. Here is the IRQ
snapshot on the same system booted as IA-32 with Zwane's patch applied:
zorro-tb2:~ # cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5
CPU6 CPU7
0: 21287 95050 0 0 0 0
0 0 IO-APIC-edge timer
4: 35 0 0 0 0 0
0 0 IO-APIC-edge serial
8: 2 0 0 0 0 0
0 0 IO-APIC-edge rtc
9: 1 0 0 0 0 0
0 0 IO-APIC-level acpi
14: 42 0 0 0 0 0
0 0 IO-APIC-edge ide0
16: 166 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb1
18: 0 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb3
19: 13 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb2
22: 3 0 0 0 0 0
0 0 IO-APIC-level ohci1394
23: 3 0 0 0 0 0
0 0 IO-APIC-level ehci_hcd:usb4
96: 4531 0 0 0 0 0
0 0 IO-APIC-level aic7xxx
97: 15 0 0 0 0 0
0 0 IO-APIC-level aic7xxx
192: 319 0 0 0 0 0
0 0 IO-APIC-level eth0
480: 197 0 0 0 0 0
0 0 IO-APIC-level eth1
NMI: 0 0 0 0 0 0
0 0
LOC: 112387 113275 108500 112878 113213 113158
113272 113249
ERR: 0
MIS: 0
After I applied my patch on top of his patch, the picture became:
zorro-tb2:~ # cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5
CPU6 CPU7
0: 21339 82235 0 0 0 0
0 0 IO-APIC-edge timer
4: 13 0 0 0 0 0
0 0 IO-APIC-edge serial
8: 2 0 0 0 0 0
0 0 IO-APIC-edge rtc
9: 1 0 0 0 0 0
0 0 IO-APIC-level acpi
14: 42 0 0 0 0 0
0 0 IO-APIC-edge ide0
16: 0 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb3
17: 4533 0 0 0 0 0
0 0 IO-APIC-level aic7xxx
18: 15 0 0 0 0 0
0 0 IO-APIC-level aic7xxx
21: 172 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb1
22: 13 0 0 0 0 0
0 0 IO-APIC-level uhci_hcd:usb2
23: 3 0 0 0 0 0
0 0 IO-APIC-level ehci_hcd:usb4
24: 3 0 0 0 0 0
0 0 IO-APIC-level ohci1394
25: 252 0 0 0 0 0
0 0 IO-APIC-level eth0
26: 115 0 0 0 0 0
0 0 IO-APIC-level eth1
NMI: 0 0 0 0 0 0
0 0
LOC: 99762 100508 95782 100288 100309 100517
100550 100349
ERR: 0
MIS: 0
So, there is no conflict between the two, and when it's fully
implemented, tested, and incorporated into the source (and into x86_64),
well, we still will have IRQs numbers utilized better per node.
Thanks,
--Natalie
I actually tested the code I'm offering with Zwane's IA-32 vector
sharing patch. By the way, I tested hi
> On Thu, May 19, 2005 at 04:06:13AM -0700,
> Natalie.Protasevich@xxxxxxxxxx wrote:
> >
> > I suggest to change the way IRQs are handed out
> to PCI devices.
> > Currently, each I/O APIC pin gets associated with an
> IRQ, no matter if
> > the pin is used or not. It is expected that each pin
> can potentually
> > be engaged by a device inserted into the
> corresponding PCI slot.
> > However, this imposes severe limitation on systems
> that have designs
> > that employ many I/O APICs, only utilizing couple lines
> of each, such
> > as P64H2 chipset. It is used in ES7000, and currently,
> there is no way
> > to boot the system with more that 9 I/O APICs. The
> simple change below
> > allows to boot a system with say 64 (or more)
> I/O APICs, each
> > providing 1 slot, which otherwise impossible because
> of the IRQ gaps
> > created for unused lines on each I/O APIC. It does
> not resolve the
> > problem with number of devices that exceeds number of
> possible IRQs,
> > but eases up a tension for IRQs on any large system
> with potentually
> > large number of devices. I only implemented this for
> the ACPI boot,
> > since if the system is this big and .. deleted...
>
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