linux::cpuinfo(3)
NAME
Linux::Cpuinfo - Object Oriented Interface to
/proc/cpuinfo
SYNOPSIS
# Old interface ( for single processor devices )
use Linux::Cpuinfo;
my $cpu = Linux::Cpuinfo->new();
die ('Could not find cpu info (does /proc/cpuinfo exists?)')
unless ref $cpu;
print $cpu->model_name();
# New Interface ( copes with SMP ).
my $cpuinfo = Linux::Cpuinfo->new();
$cnt = $cpuinfo->num_cpus(); # > 1 for an SMP system
foreach my $cpu ( $cpuinfo->cpus() )
{
print $cpu->bogomips(),"0;
}
DESCRIPTION
On Linux systems various information about the CPU ( or
CPUs ) in the computer can be gleaned from
"/proc/cpuinfo". This module provides an object oriented
interface to that information for relatively simple use in
Perl programs.
METHODS
- The interface has changed between revisions 1.2 and 1.3 of
this module in order to deal with systems with multiple
CPUs - now the details of a CPU are acquired by the meth
ods of the Linux::Cpuinfo::Cpu objects returned by the
"cpu()" and "cpus()" methods of this class. However in
order to retain backward compatibility if the methods
described for Linux::Cpuinfo::Cpu are called a
Linux::Cpuinfo object then it will work as previously returning the details of the sole CPU on a single proces
sor system and the last discovered - CPU on system with multiple processors ( this was the
- implicit behaviour on previous versions). Whilst not
strictly deprecated this interface is not the recommended
one. - cpuinfo
- Returns a blessed object suitable for calling the rest
of the methods on or a false value if for some reason
"/proc/cpuinfo" cant be opened. The first argument
can be an alternative file that provides identical
information. You may also supply a hashref containing
other arguments - the valid keys are - NoFatal
The default behaviour is for the method to croak if
an attribute is requested that is not available on
this particular CPU. If this argument is supplied
with a true value then the method will return undef
instead. - num_cpus
Returns the number of CPUs reported for this system.
- cpu SCALAR $cpu
Returns an object of type Linux::Cpuinfo::Cpu corre
sponding to the CPU of index $cpu ( where $cpu >= 0
and $cpu < num_cpus() ) - if $cpu is omitted this will return an object correspnding to the last CPU found.If $cpu is out of bounds with respect to the number of
CPUs then it will be set to the first or last CPU (
depending whether $cpu was < 0 or >num_cpus ) - cpus
Returns a list containing objects of type
Linux::Cpuinfo::Cpu corresponding to the CPUs discov
ered in this system. If the method is called in a
scalar context it will return a reference to an array
of those objects. - PER CPU METHODS OF Linux::Cpuinfo::Cpu
- Note that not all of the methods listed here are available
on all CPU types. For instance, MIPS CPUs have no cpuid
instruction, but might sport a byte order attribute. - There are also some other methods available for some CPUs
which aren't listed here. - processor
This is the index of the processor this information is
for, it will be zero for a the first CPU (which is the
only one on single-proccessor systems), one for the
second and so on. - vendor_id
This is a vendor defined string for X86 CPUs such as
'GenuineIntel' or 'AuthenticAMD'. 12 bytes long, since
it is returned via three 32 byte long registers. - cpu_family
This should return an integer that will indicate the
'family' of the processor - This is for instance '6'
for a Pentium III. Might be undefined for non-X86
CPUs. - model or cpu_model
An integer that is probably vendor dependent that
indicates their version of the above cpu_family - model_name
A string such as 'Pentium III (Coppermine)'.
- stepping
I'm lead to believe this is a version increment used
by intel. - cpu_mhz
I guess this is self explanatory - it might however be
different to what it says on the box. The Mhz is mea
sured at boot time by the kernel and represents the
true Mhz at that time. - bus_mhz
The MHz of the bus system.
- cache_size
The cache size for this processor - it might well have
the units appended ( such as 'KB' ) - fdiv_bug
True if this bug is present in the processor.
- hlt_bug
True if this bug is present in the processor.
- sep_bug
True if this bug is present in the processor.
- f00f_bug
True if this bug is present in the processor.
- coma_bug
True if this bug is present in the processor.
- fpu True if the CPU has a floating point unit.
- fpu_exception
True if the floating point unit can throw an excep
tion. - cpuid_level
The "cpuid" assembler instruction is only present on
X86 CPUs. This attribute represents the level of the
instruction that is supported by the CPU. The first
CPUs had only level 1, newer chips have more levels
and can thus return more information. - wp No idea what this is on X86 CPUs.
- flags
This is the set of flags that the CPU supports - this
is returned as an array reference. - byte_order
The byte order of the CPU, might be little endian or
big endian, or undefined for unknown. - bogomips
A system constant calculated when the kernel is booted
- it is a (rather poor) measure of the CPU's perfor
mance. - EXPORT
- None by default.
BUGS
The enormous bug in this is that I didnt realize when I
made this that the contents of "/proc/cpuinfo " are dif
ferent for different processors.
I really would be indebted if Linux users from other than
x86 processors would help me document this properly.
COPYRIGHT AND LICENSE
See the README file in the Distribution Kit
AUTHOR
Jonathan Stowe, <gellyfish@gellyfish.com>
SEE ALSO
- perl.