Skip to contentSkip to conversation

2.4.7: wtf is "ksoftirqd_CPU0"

DISCUSSION peter k. 8 participants 11 messages Jul 21, 2001 – Jul 23, 2001

lore
Share & tools
lore

peter k.

author
#0 lore raw

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

author
#1 lore raw

i knew that i forgot to say something: i was using 2.4.6 before and i never saw that process with 2.4.6 or any other 2.4.x version

Quoted 1 line

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is

started

Quoted 1 line

automatically when booting (by the kernel obviously)? why? what does it

do?

Quoted 2 lines

i didnt find any useful information on it in linuxdoc / linux-kernel archives

#2 lore raw
In reply to peter k.
Quoted 5 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

it is used internally, ignore it.

Signature · 3 lines
Jeff Garzik      | "I wouldn't be so judgemental
Building 1024    |  if you weren't such a sick freak."
MandrakeSoft     |             -- goats.com
#3 lore raw
Quoted 8 lines · Jeff Garzik
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

it is used internally, ignore it.

I'd advise not to do so in general: It is a rather tempting name for crackers to hide illegal activities.

Signature · 2 lines
Horst von Brand                             [email protected]
Casilla 9G, Vin~a del Mar, Chile                               +56 32 672616
#4 lore raw
In reply to Jeff Garzik
Quoted 8 lines · Horst von Brand
Quoted 6 lines · Jeff Garzik
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

Quoted 4 lines
Quoted 1 line

it is used internally, ignore it.

I'd advise not to do so in general: It is a rather tempting name for crackers to hide illegal activities.

Kernel daemons/threads still use "reserved pids" (< 100 I believe) so it's pretty to distinguish them. Ofcourse on 128-way SMP machine, things would be rather difficult.

Best regards,

Pascal

Quoted 8 lines
Signature · 7 lines
Horst von Brand                             [email protected]
Casilla 9G, Vin~a del Mar, Chile                               +56 32 672616
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
#5 lore raw
In reply to peter k.
Quoted 7 lines · Jeff Garzik
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

it is used internally, ignore it.

It's pretty hard to ignore a process with a name that ugly ;-)

How about just ksoft0 ? Or kirq0?

I don't see the sense of trying to encode a whole sentence into the process name.

(Peter, this handles softirqs in a more predictable way by allowing the scheduler to take care of any softirq that can't conveniently be executed immediately. Among other benefits, this approach eliminated the need to check for and execute pending softirqs on exit from system calls.)

--
Daniel

#6 lore raw
In reply to peter k.
Quoted 7 lines · Daniel Phillips
Quoted 6 lines · Jeff Garzik
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

Quoted 5 lines
Quoted 1 line

it is used internally, ignore it.

It's pretty hard to ignore a process with a name that ugly ;-)

How about just ksoft0 ? Or kirq0?

Now this is just getting silly. It follows the same convention the 6-8 other k* daemons follow. Would you want kswpd? kupd? kreclmd? Probably not.

Signature · 2 lines
Tom Rini (TR1265)
http://gate.crashing.org/~trini/
#7 lore raw
In reply to peter k.

Actually -- is it possible (or desirable) to make ALL kernel daemons begin with say "_" or some other special character to distinguish them from userland threads? The "k......d" paradigm is OK but not very distinctive. That way you have a simple line in the kernel docs that says "Any process with a leading _ is a kernel process and should NEVER be killed or otherwise messed with except as noted elsewhere in the docs".

Also would make it easy for things like ps, top and other process-aware things to have a really simple "show kernel processes only" option.

----- Original Message -----
From: "Tom Rini" <[email protected]>
To: "Daniel Phillips" <[email protected]>
Cc: "peter k." <[email protected]>;
<[email protected]>
Sent: Saturday, July 21, 2001 7:53 PM
Subject: [OT] Re: 2.4.7: wtf is "ksoftirqd_CPU0"

Quoted 8 lines · Daniel Phillips
Quoted 7 lines · Jeff Garzik
Quoted 6 lines
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

Quoted 8 lines
Quoted 5 lines
Quoted 1 line

it is used internally, ignore it.

It's pretty hard to ignore a process with a name that ugly ;-)

How about just ksoft0 ? Or kirq0?

Now this is just getting silly. It follows the same convention the 6-8 other k* daemons follow. Would you want kswpd? kupd? kreclmd?

Probably

Quoted 10 lines

not.

--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

#8 lore raw
Quoted 6 lines · Mike Black

Actually -- is it possible (or desirable) to make ALL kernel daemons begin with say "_" or some other special character to distinguish them from userland threads? The "k......d" paradigm is OK but not very distinctive. That way you have a simple line in the kernel docs that says "Any process with a leading _ is a kernel process and should NEVER be killed or otherwise messed with except as noted elsewhere in the docs".

It is rather easy to fake any process name.

Signature · 2 lines
Horst von Brand                             [email protected]
Casilla 9G, Vin~a del Mar, Chile                               +56 32 672616
#9 lore raw
In reply to peter k.

"Mike Black" <[email protected]> writes:

|> Actually -- is it possible (or desirable) to make ALL kernel daemons begin
|> with say "_" or some other special character to distinguish them from
|> userland threads?  The "k......d" paradigm is OK but not very distinctive.
|> That way you have a simple line in the kernel docs that says "Any process
|> with a leading _ is a kernel process and should NEVER be killed or otherwise
|> messed with except as noted elsewhere in the docs".
|> 
|> Also would make it easy for things like ps, top and other process-aware
|> things to have a really simple "show kernel processes only" option.

Kernel threads can easily be identified by having a zero virtual size.

Andreas.

Signature · 5 lines
Andreas Schwab                                  "And now for something
SuSE Labs                                        completely different."
[email protected]
SuSE GmbH, Schanzäckerstr. 10, D-90443 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
#10 lore raw
In reply to peter k.
Quoted 10 lines · Tom Rini
Quoted 9 lines · Daniel Phillips
Quoted 7 lines · Jeff Garzik
Quoted 4 lines · peter k.

i just installed 2.4.7, now a new process called "ksoftirqd_CPU0" is started automatically when booting (by the kernel obviously)? why? what does it do? i didnt find any useful information on it in linuxdoc / linux-kernel archives

it is used internally, ignore it.

Quoted 7 lines
Quoted 3 lines

It's pretty hard to ignore a process with a name that ugly ;-)

How about just ksoft0 ? Or kirq0?

Now this is just getting silly. It follows the same convention the 6-8 other k* daemons follow. Would you want kswpd? kupd? kreclmd? Probably not.

Err, wasn't I arguing *against* trying to encode whole sentences in the daemon names? Personally, I have a similar distaste for naming strategies that involve leaving out the vowels.

And no, I don't really like kirq or ksoft very much either.

I'd like to see the following in my ps -A list:

kupdate
kflush
kinterrupt

Something like that. We don't need d's at the ends because we have k's at the beginnings, don't you think? I can see the logic for appending numbers to per-processor daemons, but as for doing it even on UP kernels, it's not so obviously a good idea.

As far as 'naming conventions' for daemons go, they went out the window when kflushd became bdflush.

--
Daniel