26

Chapter 2. The

proc

File System

  processor

  Provides each processor with an identifying number. If you only have one processor,

you will only see a

0

.

  cpu family

  Authoritatively tells you the type of processor you have in the system. If your

computer is an Intel based system, simply place the number in front of "86" to determine the value.

This is particularly helpful if you are wondering about the architecture of an older system such

as the 586, 486, or 386. Because some RPM packages are compiled for each of these particular

architectures, this value enables you determine which package to install.

  model name

  Gives you the common name of the processor, including its project name.

  cpu MHz

  Shows the precise speed in megahertz for the processor to the thousandth decimal

point.

  cache size

  Tells you the amount of level 2 memory cache available to the processor.

  flags

  Defines a number of different qualities about the processor, such as the presence of a

floating point unit (FPU) and the ability to process MMX instructions.

2.2.4.

/proc/devices

This file displays the various character and block devices currently configured for use with the kernel.

It does not include devices whose modules are not loaded into the kernel. Below is a sample output

from this virtual file:

Character devices:

1 mem

2 pty

3 ttyp

4 ttyS

5 cua

7 vcs

10 misc

14 sound

29 fb

36 netlink

128 ptm

129 ptm

136 pts

137 pts

162 raw

254 iscsictl

Block devices:

1 ramdisk

2 fd

3 ide0

9 md

22 ide1

The output from

/proc/devices

includes the major number and name of the device and is broken

into two major sections:

Character devices

and

Block devices

.

Character devices are similar to block devices, except for two basic differences.

Block devices have a buffer available, allowing them to order requests before dealing with them. This

is important for devices designed to store information   such as hard drives   because the ability

to order the information before writing it to the device allows it to be placed in more efficient order.

Character devices do not require buffering.