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Detecting SMP in user space

Linux-ia64 Bill Nottingham 4 participants 10 messages Apr 19, 2001 – Apr 20, 2001

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Bill Nottingham

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#0 lore raw
Quoted 5 lines · Andreas Schwab

|> How about simply running 'top' or a 'dmesg | grep CPU'?

As I already said, I'm running a UP kernel, thus top only ever sees one CPU. The latter fails if the boot messages have already been cleared from the kernel log.

I believe the ACPI boot messages on ia64 tell you how many processors it found.

Bill

#1 lore raw

Bill Nottingham <[email protected]> writes:

|> Andreas Schwab ([email protected]) said: 
|> > |> How about simply running 'top' or a 'dmesg | grep CPU'?
|> > 
|> > As I already said, I'm running a UP kernel, thus top only ever sees one
|> > CPU.  The latter fails if the boot messages have already been cleared from
|> > the kernel log.
|> 
|> I believe the ACPI boot messages on ia64 tell you how many processors
|> it found.

How can I get at the ACPI boot messages if the kernel log is already cleared?

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
#2 lore raw
In reply to Bill Nottingham

Andreas-

On my system the boot messages are copied into `/var/log/messages' so you can always go there even if the boot log is cleared.

Quoted 28 lines · Andreas Schwab

Bill Nottingham <[email protected]> writes:

|> Andreas Schwab ([email protected]) said: 
|> > |> How about simply running 'top' or a 'dmesg | grep CPU'?
|> > 
|> > As I already said, I'm running a UP kernel, thus top only ever sees one
|> > CPU.  The latter fails if the boot messages have already been cleared from
|> > the kernel log.
|> 
|> I believe the ACPI boot messages on ia64 tell you how many processors
|> it found.

How can I get at the ACPI boot messages if the kernel log is already cleared?

Andreas.

Signature · 10 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

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Signature · 4 lines
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
[email protected]
Ph: 303/938-9838
#3 lore raw
In reply to Bill Nottingham

Don Dugger <[email protected]> writes:

|> Andreas-
|> 
|> On my system the boot messages are copied into `/var/log/messages'
|> so you can always go there even if the boot log is cleared.

This is not reliable. I need something that I can use without depending on the kernel messages. Is it possible to get at the ACPI tables in user space?

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
#4 lore raw
In reply to Bill Nottingham

At least on i386, root can read the ACPI tables from /dev/mem (as done in the pmtools [acpitools] package).

~Randy________________________
-----------------------------------------------

Quoted 21 lines

-----Original Message-----
From: Andreas Schwab [mailto:[email protected]]
Sent: Thursday, April 19, 2001 7:31 AM
To: Don Dugger
Cc: [email protected]
Subject: Re: [Linux-ia64] Re: Detecting SMP in user space

Don Dugger <[email protected]> writes:

|> Andreas-
|> 
|> On my system the boot messages are copied into `/var/log/messages'
|> so you can always go there even if the boot log is cleared.

This is not reliable. I need something that I can use without depending
on the kernel messages. Is it possible to get at the ACPI tables in user space?

Andreas.

#5 lore raw
In reply to Bill Nottingham

"Dunlap, Randy" <[email protected]> writes:

|> At least on i386, root can read the ACPI tables from |> /dev/mem (as done in the pmtools [acpitools] package).

Where can I get this package?

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
#6 lore raw
In reply to Bill Nottingham

At the bottom of
http://developer.intel.com/technology/IAPC/acpi/downloads.htm

~Randy________________________503-677-5408_____
-----------------------------------------------

Quoted 9 lines

-----Original Message-----
From: Andreas Schwab [mailto:[email protected]]

"Dunlap, Randy" <[email protected]> writes:

|> At least on i386, root can read the ACPI tables from |> /dev/mem (as done in the pmtools [acpitools] package).

Where can I get this package?

#7 lore raw
In reply to Bill Nottingham

"Dunlap, Randy" <[email protected]> writes:

|> At the bottom of
|> http://developer.intel.com/technology/IAPC/acpi/downloads.htm

Thanks, this works fine for BigSur. But on Lion I only get:

RSDP "MSLSAL" @ 0x000f57b0
0000: 52 53 44 20 50 54 52 20 00 4d 53 4c 53 41 4c 00 RSD PTR .MSLSAL.
0010: 00 00 00 00 ....

acpidmp: cannot map the RSDT

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
#8 lore raw
In reply to Bill Nottingham

Ah, without actually looking at the code, I believe that you have proven that acpidmp doesn't understand ACPI 2.0 data structures.

Sorry about that. I don't know what the plans are for updating acpidmp (if any).

~Randy________________________503-677-5408_____
-----------------------------------------------

Quoted 18 lines

-----Original Message-----
From: Andreas Schwab [mailto:[email protected]]

"Dunlap, Randy" <[email protected]> writes:

|> At the bottom of
|> http://developer.intel.com/technology/IAPC/acpi/downloads.htm

Thanks, this works fine for BigSur. But on Lion I only get:

RSDP "MSLSAL" @ 0x000f57b0
0000: 52 53 44 20 50 54 52 20 00 4d 53 4c 53 41 4c 00 RSD
PTR .MSLSAL.
0010: 00 00 00 00 ....

acpidmp: cannot map the RSDT

Andreas.

#9 lore raw
In reply to Bill Nottingham

"Dunlap, Randy" <[email protected]> writes:

|> Ah, without actually looking at the code, I believe that
|> you have proven that acpidmp doesn't understand ACPI 2.0
|> data structures.

I don't think this is a problem with ACPI 2.0. The Lions have the ACPI structures (both pre 2.0 and 2.0) located at adresses above 0x3f000000, but acpidump only looks at the region 0xe0000 to 0x100000. The structure located at 0x000f57b0 doesn't contain a valid ACPI 2.0 structure either (the xsdt pointer is garbage).

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