Meaninf of /proc/interrupts ??
Chirayu Patel
Hi,
This are the contents of /proc/interrupt in my machine.
Can someone tell me the meaning of the numbers in the second column. And,
what does the "+" sign mean.
./interrupts
0: 9815862 timer
1: 85278 keyboard
2: 0 cascade
4: 330855 + serial
5: 616759 NE2000
8: 0 + rtc
13: 1 math error
14: 1576783 + ide0
Thankx in advance.
Bye
Chirayu
Frank Sweetser
Chirayu Patel <chi...@idc.tandem.com> writes:
Well, the second field is the number of times that particular error has
been triggered. So, from your system, you can tell it's got heavy disk
use, light network use, and probably a modem installed. As for the '+',
I'm not sure, but I think it means that the interrupt is pending at that
moment.
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Albert D. Cahalan
Chirayu Patel <chi...@idc.tandem.com> writes:
> This are the contents of /proc/interrupt in my machine.
> Can someone tell me the meaning of the numbers in the second column.
> And, what does the "+" sign mean.
>
> 0: 9815862 timer
> 1: 85278 keyboard
> 2: 0 cascade
> 4: 330855 + serial
> 5: 616759 NE2000
> 8: 0 + rtc
> 13: 1 math error
> 14: 1576783 + ide0
Coulmn 2 is the number of times the interrupt was used.
The '+' indicates fast interrupt handlers. Interrupts may not
be shared by both fast and slow interrupt handlers. (that is
what let a 386 do 115 kb/s on a normal serial port, but it
should be replaced by a smart interrupt system)
--
--
Albert Cahalan <acahalan at cs.uml.edu> My address may be mangled to
avoid junk email. Please check it if you wish to respond to a news post.
Bob Hauck
In article <wvyraco...@ernie.wpi.edu>,
Frank Sweetser <rasm...@ernie.WPI.EDU> writes:
> Chirayu Patel <chi...@idc.tandem.com> writes:
>> Can someone tell me the meaning of the numbers in the second column. And,
>> what does the "+" sign mean.
>>
>> ./interrupts
>> 0: 9815862 timer
>> 1: 85278 keyboard
>> 2: 0 cascade
>> 4: 330855 + serial
>> 5: 616759 NE2000
>> 8: 0 + rtc
>> 13: 1 math error
>> 14: 1576783 + ide0
> Well, the second field is the number of times that particular error has
> been triggered.
> As for the '+', I'm not sure, but I think it means that the interrupt
> is pending at that moment.
I was curious, so I took a minute to check into this, since the '+'
is always there on some IRQ's on this machine (slow day).
A quick read through the kernel sources reveals that the '+' means
that those are "fast" irq's, ones where the handler runs with other
interrupts disabled. See the comments at the top of ../arch/i386/irq.c
and then search for SA_INTERRUPT. You'll eventually come to the actual
lines of kernel code that builds the above table (get_irq_list()).
---
Bob Hauck bo...@wasatch.com
Wasatch Communications Group http://www.wasatch.com
Neil Moore
> >
> > Can someone tell me the meaning of the numbers in the second column. And,
> > what does the "+" sign mean.
>
> Well, the second field is the number of times that particular error has
> use, light network use, and probably a modem installed.
Actually, I'd say with only 3.3e5 interrupts triggered over the course of
about 27 hours (assuming e has an ix86), that serial interrupt could be a
mouse. Over the past 50 hours, I have had over 7 million serial interrupts
on my modem's IRQ, but then again I leave my 14.4 modem connected 23 hours
a day.
> As for the '+', I'm not sure, but I think it means that the interrupt
> is pending at that moment.
Nope. It means that the handler is `fast' (has the SA_INTERRUPT bit set).
This means:
on the ix86 and MIPS, the handler is called with interrupts disabled.
on the MIPS, a faster return is used
on the Alpha, MIPS, Sparc, and Sparc64, a fast and a slow handler
may not share the same IRQ.
on all architectures except the m68k and the ix86, a "+" is displayed
in /proc/interrupts
These are the 2.1.47 semantics, BTW. On 2.0.x for the ix86:
a faster return is used
fast/slow sharing is disallowed
a "+" is displayed in /proc/interrupts
I don't know about the semantics for other architectures under 2.0.x,
as I don't have a copy of the source handy.
For more information, see linux/arch/*/kernel/irq.c and (on the MIPS
and on the ix86 under 2.0.x) linux/arch/*/kernel/entry.S .
--
-Neil Moore http://www.sfhs.floyd.k12.ky.us/~amethyst/
(finger amet...@valjean.sfhs.floyd.k12.ky.us for my Geek Code)