Re: [SLE] top says "2.4+ kernel w/o ELF notes? -- report this"

15 Feb 2006

      On Wednesday 15 February 2006 22:10, Steve Graegert wrote:
...
On 2/15/06, AD Marshall  wrote:
...
I've been on suse 9.3 for almost a year now and never noticed this before:
$ top
2.4+ kernel w/o ELF notes? -- report this
Unknown HZ value! (92) Assume 100.
top - 21:00:10 up 5 days,  4:18,  8 users,  load average: 1.28, 1.23, 1.03
[...]
Since those first two lines from top disappear almost immediately, i'm not sure whether this is new or not. I don't immediatey see anything /var/log/messages about it. But top says "report this", so i'm submitting. Anyone have any suggestions as to what i should do with this?
I'm using:
$ uname -a
Linux tpad01 2.6.11.4-21.10-default #1 Tue Nov 29 14:32:49 UTC 2005 i686 i686 i386 GNU/Linux
$ top -v
2.4+ kernel w/o ELF notes? -- report this
Unknown HZ value! (92) Assume 100.
       top: procps version 3.2.5
What you experience here is the fact that the kernel was not able to
get the correct HZ (kernel clock tick rate) value for your processor. 
This does not mean that there is something wrong with the
configuration or your machine.
Older kernels try to count CPUs in /proc/stat to get the correct HZ
value.  2.4+ kernels try to obtain it from the ELF notes, which is not
necessarily supported by the kernel.  If this fails, the kernel tries
to obtain the HZ value by calculating it from the jiffies (1/HZ):
jiffies = user_j + nice_j + sys_j + other_j;
  seconds = (up_1 + up_2) / 2;
  h = (unsigned)( (double)jiffies/seconds/smp_num_cpus );
Here, h contains a value that is contained in the kernel to identify
the CPU it is running on.  On 32-bit and some big endian machines this
calculation can fail and the HZ value and is set to 100.  Your kernel
returned 92 which is not a valid value in the kernel.  Values ranging
from 95 to 105 indicate a i386 Linux.
\Steve
--
Steve Graegert 
Software Consultant {C/C++ && Java && .NET}
Office: +49 9131 7123988
Mobile: +49 1520 9289212
That was a great explanation, Steve.  Thanks a lot. 

"Jiffies", eh?  Have to look this up...

-- 
AD Marshall
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