[Linux-ia64] Interrupt redirection problem

[Linux-ia64] Interrupt redirection problem

[Andreas Schwab]

This is the output of /proc/interrupts on a Lion that has been up for 9 days:

           CPU0       CPU1       CPU2       CPU3       
 32:       2226         19          0          0   IO-SAPIC-edge  keyboard
 33:          2          2          0          0   IO-SAPIC-edge  ide1
 34:          4          2          0          0   IO-SAPIC-edge  ide0
 36:          0          0          0          0   IO-SAPIC-edge  PS/2 Mouse
 44:       1180        131          2         47   IO-SAPIC-edge  serial
 48:   22811357    1510005      31585     155591  IO-SAPIC-level  eth0
 54:          0          0          0          0  IO-SAPIC-level  usb-uhci
 61:    4485678     808931      11218      97495  IO-SAPIC-level  qla1280
238:          0          0          0          0           SAPIC  perfmon
239:  796793291  796794391  796795076  796794435           SAPIC  timer
254:    8256864   11570234   11685908   11611853           SAPIC  IPI
NMI:          0          0          0          0 
ERR:          0

As you can see, cpu0 is processing the majority of interrupts (91%,
ignoring the SAPIC interrupts).  Why?

Andreas.

-- 
Andreas Schwab                                  "And now for something
SuSE Labs                                        completely different."
Andreas.Schwab@suse.de
SuSE GmbH, Schanzäckerstr. 10, D-90443 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5

Re: [Linux-ia64] Interrupt redirection problem

[Martin Wilck]

Andreas Schwab wrote:
>
> As you can see, cpu0 is processing the majority of interrupts (91%,
> ignoring the SAPIC interrupts).  Why?

This is not the case on my system. On the contrary, CPU3 seems to receive
the vast majority of interrupts. (I have "Force IRQ redirection" enabled).

 52:        139          1        671     167542  IO-SAPIC-level  e100
 54:          0          0          0          0  IO-SAPIC-level  usb-uhci
 57:          0          0          5       8072  IO-SAPIC-level  Mylex eXtremeRAID 2000
 61:         21          1       1856      66170  IO-SAPIC-level  qla1280
 63:          0          0        178       3896  IO-SAPIC-level  aic7xxx

Martin

-- 
Martin Wilck     <Martin.Wilck@fujitsu-siemens.com>
FSC EP PS DS1, Paderborn      Tel. +49 5251 8 15113

RE: [Linux-ia64] Interrupt redirection problem

[Miller, Mike (OS Dev)]

I think it's actually the BSP that processes most of the interrupts. It
could be cpu0 on one boot, and another cpu on a subsequent boot.

mikem

-----Original Message-----
From: Martin Wilck [mailto:Martin.Wilck@fujitsu-siemens.com]
Sent: Wednesday, June 27, 2001 3:22 AM
To: Linux-IA64 Mailing list
Subject: Re: [Linux-ia64] Interrupt redirection problem



Andreas Schwab wrote:
>
> As you can see, cpu0 is processing the majority of interrupts (91%,
> ignoring the SAPIC interrupts).  Why?

This is not the case on my system. On the contrary, CPU3 seems to receive
the vast majority of interrupts. (I have "Force IRQ redirection" enabled).

 52:        139          1        671     167542  IO-SAPIC-level  e100
 54:          0          0          0          0  IO-SAPIC-level  usb-uhci
 57:          0          0          5       8072  IO-SAPIC-level  Mylex
eXtremeRAID 2000
 61:         21          1       1856      66170  IO-SAPIC-level  qla1280
 63:          0          0        178       3896  IO-SAPIC-level  aic7xxx

Martin

-- 
Martin Wilck     <Martin.Wilck@fujitsu-siemens.com>
FSC EP PS DS1, Paderborn      Tel. +49 5251 8 15113




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