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phoenix |
------------------------------------------------------------------------------
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T H E /proc F I L E S Y S T E M
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------------------------------------------------------------------------------
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/proc/sys Terrehon Bowden October 7 1999
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Bodo Bauer
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2.4.x update Jorge Nerin November 14 2000
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------------------------------------------------------------------------------
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Version 1.3 Kernel version 2.2.12
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Kernel version 2.4.0-test11-pre4
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------------------------------------------------------------------------------
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Table of Contents
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-----------------
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0.1 Introduction/Credits
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0.2 Legal Stuff
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1 Collecting System Information
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1.1 Process-Specific Subdirectories
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1.2 Kernel data
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1.3 IDE devices in /proc/ide
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1.4 Networking info in /proc/net
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1.5 SCSI info
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1.6 Parallel port info in /proc/parport
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1.7 TTY info in /proc/tty
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2 Modifying System Parameters
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2.1 /proc/sys/fs - File system data
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2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
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2.3 /proc/sys/kernel - general kernel parameters
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2.4 /proc/sys/vm - The virtual memory subsystem
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2.5 /proc/sys/dev - Device specific parameters
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2.6 /proc/sys/sunrpc - Remote procedure calls
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2.7 /proc/sys/net - Networking stuff
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2.8 /proc/sys/net/ipv4 - IPV4 settings
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2.9 Appletalk
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2.10 IPX
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------------------------------------------------------------------------------
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Preface
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------------------------------------------------------------------------------
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0.1 Introduction/Credits
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------------------------
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This documentation is part of a soon (or so we hope) to be released book on
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the SuSE Linux distribution. As there is no complete documentation for the
|
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/proc file system and we've used many freely available sources to write these
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chapters, it seems only fair to give the work back to the Linux community.
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This work is based on the 2.2.* kernel version and the upcoming 2.4.*. I'm
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afraid it's still far from complete, but we hope it will be useful. As far as
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we know, it is the first 'all-in-one' document about the /proc file system. It
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is focused on the Intel x86 hardware, so if you are looking for PPC, ARM,
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SPARC, APX, etc., features, you probably won't find what you are looking for.
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It also only covers IPv4 networking, not IPv6 nor other protocols - sorry. But
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additions and patches are welcome and will be added to this document if you
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mail them to Bodo.
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We'd like to thank Alan Cox, Rik van Riel, and Alexey Kuznetsov and a lot of
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other people for help compiling this documentation. We'd also like to extend a
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special thank you to Andi Kleen for documentation, which we relied on heavily
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to create this document, as well as the additional information he provided.
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Thanks to everybody else who contributed source or docs to the Linux kernel
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and helped create a great piece of software... :)
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If you have any comments, corrections or additions, please don't hesitate to
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contact Bodo Bauer at bb@ricochet.net. We'll be happy to add them to this
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document.
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The latest version of this document is available online at
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http://skaro.nightcrawler.com/~bb/Docs/Proc as HTML version.
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If the above direction does not works for you, ypu could try the kernel
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mailing list at linux-kernel@vger.kernel.org and/or try to reach me at
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comandante@zaralinux.com.
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0.2 Legal Stuff
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---------------
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We don't guarantee the correctness of this document, and if you come to us
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complaining about how you screwed up your system because of incorrect
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documentation, we won't feel responsible...
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------------------------------------------------------------------------------
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CHAPTER 1: COLLECTING SYSTEM INFORMATION
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------------------------------------------------------------------------------
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------------------------------------------------------------------------------
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In This Chapter
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------------------------------------------------------------------------------
|
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* Investigating the properties of the pseudo file system /proc and its
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ability to provide information on the running Linux system
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* Examining /proc's structure
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* Uncovering various information about the kernel and the processes running
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on the system
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------------------------------------------------------------------------------
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|
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The proc file system acts as an interface to internal data structures in the
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kernel. It can be used to obtain information about the system and to change
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certain kernel parameters at runtime (sysctl).
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First, we'll take a look at the read-only parts of /proc. In Chapter 2, we
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show you how you can use /proc/sys to change settings.
|
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|
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1.1 Process-Specific Subdirectories
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-----------------------------------
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The directory /proc contains (among other things) one subdirectory for each
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process running on the system, which is named after the process ID (PID).
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The link self points to the process reading the file system. Each process
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subdirectory has the entries listed in Table 1-1.
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Table 1-1: Process specific entries in /proc
|
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..............................................................................
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File Content
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cmdline Command line arguments
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cpu Current and last cpu in wich it was executed (2.4)(smp)
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cwd Link to the current working directory
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environ Values of environment variables
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exe Link to the executable of this process
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fd Directory, which contains all file descriptors
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maps Memory maps to executables and library files (2.4)
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mem Memory held by this process
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root Link to the root directory of this process
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stat Process status
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statm Process memory status information
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status Process status in human readable form
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..............................................................................
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For example, to get the status information of a process, all you have to do is
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read the file /proc/PID/status:
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138 |
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>cat /proc/self/status
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139 |
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Name: cat
|
140 |
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State: R (running)
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141 |
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Pid: 5452
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142 |
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PPid: 743
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143 |
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TracerPid: 0 (2.4)
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144 |
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Uid: 501 501 501 501
|
145 |
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Gid: 100 100 100 100
|
146 |
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Groups: 100 14 16
|
147 |
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VmSize: 1112 kB
|
148 |
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VmLck: 0 kB
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149 |
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VmRSS: 348 kB
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150 |
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VmData: 24 kB
|
151 |
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VmStk: 12 kB
|
152 |
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VmExe: 8 kB
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153 |
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VmLib: 1044 kB
|
154 |
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SigPnd: 0000000000000000
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155 |
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SigBlk: 0000000000000000
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156 |
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SigIgn: 0000000000000000
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157 |
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SigCgt: 0000000000000000
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CapInh: 00000000fffffeff
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159 |
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CapPrm: 0000000000000000
|
160 |
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CapEff: 0000000000000000
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This shows you nearly the same information you would get if you viewed it with
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the ps command. In fact, ps uses the proc file system to obtain its
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information. The statm file contains more detailed information about the
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process memory usage. Its seven fields are explained in Table 1-2.
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168 |
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Table 1-2: Contents of the statm files
|
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..............................................................................
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File Content
|
172 |
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size total program size
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173 |
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resident size of memory portions
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174 |
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shared number of pages that are shared
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175 |
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trs number of pages that are 'code'
|
176 |
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drs number of pages of data/stack
|
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lrs number of pages of library
|
178 |
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dt number of dirty pages
|
179 |
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..............................................................................
|
180 |
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|
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1.2 Kernel data
|
182 |
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---------------
|
183 |
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|
184 |
|
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Similar to the process entries, the kernel data files give information about
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the running kernel. The files used to obtain this information are contained in
|
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/proc and are listed in Table 1-3. Not all of these will be present in your
|
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system. It depends on the kernel configuration and the loaded modules, which
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files are there, and which are missing.
|
189 |
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|
190 |
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Table 1-3: Kernel info in /proc
|
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..............................................................................
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192 |
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File Content
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193 |
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apm Advanced power management info
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194 |
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bus Directory containing bus specific information
|
195 |
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cmdline Kernel command line
|
196 |
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cpuinfo Info about the CPU
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197 |
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devices Available devices (block and character)
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dma Used DMS channels
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199 |
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filesystems Supported filesystems
|
200 |
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driver Various drivers grouped here, currently rtc (2.4)
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201 |
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execdomains Execdomains, related to security (2.4)
|
202 |
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fb Frame Buffer devices (2.4)
|
203 |
|
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fs File system parameters, currently nfs/exports (2.4)
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204 |
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ide Directory containing info about the IDE subsystem
|
205 |
|
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interrupts Interrupt usage
|
206 |
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iomem Memory map (2.4)
|
207 |
|
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ioports I/O port usage
|
208 |
|
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irq Masks for irq to cpu affinity (2.4)(smp?)
|
209 |
|
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isapnp ISA PnP (Plug&Play) Info (2.4)
|
210 |
|
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kcore Kernel core image (can be ELF or A.OUT(deprecated in 2.4))
|
211 |
|
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kmsg Kernel messages
|
212 |
|
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ksyms Kernel symbol table
|
213 |
|
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loadavg Load average of last 1, 5 & 15 minutes
|
214 |
|
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locks Kernel locks
|
215 |
|
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meminfo Memory info
|
216 |
|
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misc Miscellaneous
|
217 |
|
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modules List of loaded modules
|
218 |
|
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mounts Mounted filesystems
|
219 |
|
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net Networking info (see text)
|
220 |
|
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partitions Table of partitions known to the system
|
221 |
|
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pci Depreciated info of PCI bus (new way -> /proc/bus/pci/,
|
222 |
|
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decoupled by lspci (2.4)
|
223 |
|
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rtc Real time clock
|
224 |
|
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scsi SCSI info (see text)
|
225 |
|
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slabinfo Slab pool info
|
226 |
|
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stat Overall statistics
|
227 |
|
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swaps Swap space utilization
|
228 |
|
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sys See chapter 2
|
229 |
|
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sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4)
|
230 |
|
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tty Info of tty drivers
|
231 |
|
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uptime System uptime
|
232 |
|
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version Kernel version
|
233 |
|
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video bttv info of video resources (2.4)
|
234 |
|
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..............................................................................
|
235 |
|
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|
236 |
|
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You can, for example, check which interrupts are currently in use and what
|
237 |
|
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they are used for by looking in the file /proc/interrupts:
|
238 |
|
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|
239 |
|
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> cat /proc/interrupts
|
240 |
|
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CPU0
|
241 |
|
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0: 8728810 XT-PIC timer
|
242 |
|
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1: 895 XT-PIC keyboard
|
243 |
|
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2: 0 XT-PIC cascade
|
244 |
|
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3: 531695 XT-PIC aha152x
|
245 |
|
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4: 2014133 XT-PIC serial
|
246 |
|
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5: 44401 XT-PIC pcnet_cs
|
247 |
|
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8: 2 XT-PIC rtc
|
248 |
|
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11: 8 XT-PIC i82365
|
249 |
|
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12: 182918 XT-PIC PS/2 Mouse
|
250 |
|
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13: 1 XT-PIC fpu
|
251 |
|
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14: 1232265 XT-PIC ide0
|
252 |
|
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15: 7 XT-PIC ide1
|
253 |
|
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NMI: 0
|
254 |
|
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|
255 |
|
|
In 2.4.* a couple of lines where added to this file LOC & ERR (this time is the
|
256 |
|
|
output of a SMP machine):
|
257 |
|
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|
258 |
|
|
> cat /proc/interrupts
|
259 |
|
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|
260 |
|
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CPU0 CPU1
|
261 |
|
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0: 1243498 1214548 IO-APIC-edge timer
|
262 |
|
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1: 8949 8958 IO-APIC-edge keyboard
|
263 |
|
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2: 0 0 XT-PIC cascade
|
264 |
|
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5: 11286 10161 IO-APIC-edge soundblaster
|
265 |
|
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8: 1 0 IO-APIC-edge rtc
|
266 |
|
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9: 27422 27407 IO-APIC-edge 3c503
|
267 |
|
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12: 113645 113873 IO-APIC-edge PS/2 Mouse
|
268 |
|
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13: 0 0 XT-PIC fpu
|
269 |
|
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14: 22491 24012 IO-APIC-edge ide0
|
270 |
|
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15: 2183 2415 IO-APIC-edge ide1
|
271 |
|
|
17: 30564 30414 IO-APIC-level eth0
|
272 |
|
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18: 177 164 IO-APIC-level bttv
|
273 |
|
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NMI: 2457961 2457959
|
274 |
|
|
LOC: 2457882 2457881
|
275 |
|
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ERR: 2155
|
276 |
|
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|
277 |
|
|
NMI is incremented in this case because every timer interrupt generates a NMI
|
278 |
|
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(Non Maskable Interrupt) which is used by the NMI Watchdog to detect lookups.
|
279 |
|
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|
280 |
|
|
LOC is the local interrupt counter of the internal APIC of every CPU.
|
281 |
|
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|
282 |
|
|
ERR is incremented in the case of errors in the IO-APIC bus (the bus that
|
283 |
|
|
connects the CPUs in a SMP system. This means that an error has been detected,
|
284 |
|
|
the IO-APIC automatically retry the transmission, so it should not be a big
|
285 |
|
|
problem, but you should read the SMP-FAQ.
|
286 |
|
|
|
287 |
|
|
In this context it could be interesting to note the new irq directory in 2.4.
|
288 |
|
|
It could be used to set IRQ to CPU affinity, this means that you can "hook" an
|
289 |
|
|
IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the
|
290 |
|
|
irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask
|
291 |
|
|
|
292 |
|
|
For example
|
293 |
|
|
> ls /proc/irq/
|
294 |
|
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|
295 |
|
|
1 11 13 15 17 19 3 5 7 9
|
296 |
|
|
> ls /proc/irq/0/
|
297 |
|
|
smp_affinity
|
298 |
|
|
|
299 |
|
|
The contents of the prof_cpu_mask file and each smp_affinity file for each IRQ
|
300 |
|
|
is the same by default:
|
301 |
|
|
|
302 |
|
|
> cat /proc/irq/0/smp_affinity
|
303 |
|
|
ffffffff
|
304 |
|
|
|
305 |
|
|
It's a bitmask, in wich you can specify wich CPUs can handle the IRQ, you can
|
306 |
|
|
set it by doing:
|
307 |
|
|
|
308 |
|
|
> echo 1 > /proc/irq/prof_cpu_mask
|
309 |
|
|
|
310 |
|
|
This means that only the first CPU will handle the IRQ, but you can also echo 5
|
311 |
|
|
wich means that only the first and fourth CPU can handle the IRQ.
|
312 |
|
|
|
313 |
|
|
The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
|
314 |
|
|
between all the CPUs which are allowed to handle it. As usual the kernel has
|
315 |
|
|
more info than you and does a better job than you, so the defaults are the
|
316 |
|
|
best choice for almost everyone.
|
317 |
|
|
|
318 |
|
|
There are three more important subdirectories in /proc: net, scsi, and sys.
|
319 |
|
|
The general rule is that the contents, or even the existence of these
|
320 |
|
|
directories, depend on your kernel configuration. If SCSI is not enabled, the
|
321 |
|
|
directory scsi may not exist. The same is true with the net, which is there
|
322 |
|
|
only when networking support is present in the running kernel.
|
323 |
|
|
|
324 |
|
|
The slabinfo file gives information about memory usage at the slab level.
|
325 |
|
|
Linux uses slab pools for memory management above page level in version 2.2.
|
326 |
|
|
Commonly used objects have their own slab pool (such as network buffers,
|
327 |
|
|
directory cache, and so on).
|
328 |
|
|
|
329 |
|
|
1.3 IDE devices in /proc/ide
|
330 |
|
|
----------------------------
|
331 |
|
|
|
332 |
|
|
The subdirectory /proc/ide contains information about all IDE devices of which
|
333 |
|
|
the kernel is aware. There is one subdirectory for each IDE controller, the
|
334 |
|
|
file drivers and a link for each IDE device, pointing to the device directory
|
335 |
|
|
in the controller specific subtree.
|
336 |
|
|
|
337 |
|
|
The file drivers contains general information about the drivers used for the
|
338 |
|
|
IDE devices:
|
339 |
|
|
|
340 |
|
|
> cat /proc/ide/drivers
|
341 |
|
|
ide-cdrom version 4.53
|
342 |
|
|
ide-disk version 1.08
|
343 |
|
|
|
344 |
|
|
|
345 |
|
|
More detailed information can be found in the controller specific
|
346 |
|
|
subdirectories. These are named ide0, ide1 and so on. Each of these
|
347 |
|
|
directories contains the files shown in table 1-4.
|
348 |
|
|
|
349 |
|
|
|
350 |
|
|
Table 1-4: IDE controller info in /proc/ide/ide?
|
351 |
|
|
..............................................................................
|
352 |
|
|
File Content
|
353 |
|
|
channel IDE channel (0 or 1)
|
354 |
|
|
config Configuration (only for PCI/IDE bridge)
|
355 |
|
|
mate Mate name
|
356 |
|
|
model Type/Chipset of IDE controller
|
357 |
|
|
..............................................................................
|
358 |
|
|
|
359 |
|
|
Each device connected to a controller has a separate subdirectory in the
|
360 |
|
|
controllers directory. The files listed in table 1-5 are contained in these
|
361 |
|
|
directories.
|
362 |
|
|
|
363 |
|
|
|
364 |
|
|
Table 1-5: IDE device information
|
365 |
|
|
..............................................................................
|
366 |
|
|
File Content
|
367 |
|
|
cache The cache
|
368 |
|
|
capacity Capacity of the medium (in 512Byte blocks)
|
369 |
|
|
driver driver and version
|
370 |
|
|
geometry physical and logical geometry
|
371 |
|
|
identify device identify block
|
372 |
|
|
media media type
|
373 |
|
|
model device identifier
|
374 |
|
|
settings device setup
|
375 |
|
|
smart_thresholds IDE disk management thresholds
|
376 |
|
|
smart_values IDE disk management values
|
377 |
|
|
..............................................................................
|
378 |
|
|
|
379 |
|
|
The most interesting file is settings. This file contains a nice overview of
|
380 |
|
|
the drive parameters:
|
381 |
|
|
|
382 |
|
|
# cat /proc/ide/ide0/hda/settings
|
383 |
|
|
name value min max mode
|
384 |
|
|
---- ----- --- --- ----
|
385 |
|
|
bios_cyl 526 0 65535 rw
|
386 |
|
|
bios_head 255 0 255 rw
|
387 |
|
|
bios_sect 63 0 63 rw
|
388 |
|
|
breada_readahead 4 0 127 rw
|
389 |
|
|
bswap 0 0 1 r
|
390 |
|
|
file_readahead 72 0 2097151 rw
|
391 |
|
|
io_32bit 0 0 3 rw
|
392 |
|
|
keepsettings 0 0 1 rw
|
393 |
|
|
max_kb_per_request 122 1 127 rw
|
394 |
|
|
multcount 0 0 8 rw
|
395 |
|
|
nice1 1 0 1 rw
|
396 |
|
|
nowerr 0 0 1 rw
|
397 |
|
|
pio_mode write-only 0 255 w
|
398 |
|
|
slow 0 0 1 rw
|
399 |
|
|
unmaskirq 0 0 1 rw
|
400 |
|
|
using_dma 0 0 1 rw
|
401 |
|
|
|
402 |
|
|
|
403 |
|
|
1.4 Networking info in /proc/net
|
404 |
|
|
--------------------------------
|
405 |
|
|
|
406 |
|
|
The subdirectory /proc/net follows the usual pattern. Table 1-6 shows the
|
407 |
|
|
additional values you get for IP version 6 if you configure the kernel to
|
408 |
|
|
support this. Table 1-7 lists the files and their meaning.
|
409 |
|
|
|
410 |
|
|
|
411 |
|
|
Table 1-6: IPv6 info in /proc/net
|
412 |
|
|
..............................................................................
|
413 |
|
|
File Content
|
414 |
|
|
udp6 UDP sockets (IPv6)
|
415 |
|
|
tcp6 TCP sockets (IPv6)
|
416 |
|
|
raw6 Raw device statistics (IPv6)
|
417 |
|
|
igmp6 IP multicast addresses, which this host joined (IPv6)
|
418 |
|
|
if_inet6 List of IPv6 interface addresses
|
419 |
|
|
ipv6_route Kernel routing table for IPv6
|
420 |
|
|
rt6_stats Global IPv6 routing tables statistics
|
421 |
|
|
sockstat6 Socket statistics (IPv6)
|
422 |
|
|
snmp6 Snmp data (IPv6)
|
423 |
|
|
..............................................................................
|
424 |
|
|
|
425 |
|
|
|
426 |
|
|
Table 1-7: Network info in /proc/net
|
427 |
|
|
..............................................................................
|
428 |
|
|
File Content
|
429 |
|
|
arp Kernel ARP table
|
430 |
|
|
dev network devices with statistics
|
431 |
|
|
dev_mcast the Layer2 multicast groups a device is listening too
|
432 |
|
|
(interface index, label, number of references, number of bound
|
433 |
|
|
addresses).
|
434 |
|
|
dev_stat network device status
|
435 |
|
|
ip_fwchains Firewall chain linkage
|
436 |
|
|
ip_fwnames Firewall chain names
|
437 |
|
|
ip_masq Directory containing the masquerading tables
|
438 |
|
|
ip_masquerade Major masquerading table
|
439 |
|
|
netstat Network statistics
|
440 |
|
|
raw raw device statistics
|
441 |
|
|
route Kernel routing table
|
442 |
|
|
rpc Directory containing rpc info
|
443 |
|
|
rt_cache Routing cache
|
444 |
|
|
snmp SNMP data
|
445 |
|
|
sockstat Socket statistics
|
446 |
|
|
tcp TCP sockets
|
447 |
|
|
tr_rif Token ring RIF routing table
|
448 |
|
|
udp UDP sockets
|
449 |
|
|
unix UNIX domain sockets
|
450 |
|
|
wireless Wireless interface data (Wavelan etc)
|
451 |
|
|
igmp IP multicast addresses, which this host joined
|
452 |
|
|
psched Global packet scheduler parameters.
|
453 |
|
|
netlink List of PF_NETLINK sockets
|
454 |
|
|
ip_mr_vifs List of multicast virtual interfaces
|
455 |
|
|
ip_mr_cache List of multicast routing cache
|
456 |
|
|
..............................................................................
|
457 |
|
|
|
458 |
|
|
You can use this information to see which network devices are available in
|
459 |
|
|
your system and how much traffic was routed over those devices:
|
460 |
|
|
|
461 |
|
|
> cat /proc/net/dev
|
462 |
|
|
Inter-|Receive |[...
|
463 |
|
|
face |bytes packets errs drop fifo frame compressed multicast|[...
|
464 |
|
|
lo: 908188 5596 0 0 0 0 0 0 [...
|
465 |
|
|
ppp0:15475140 20721 410 0 0 410 0 0 [...
|
466 |
|
|
eth0: 614530 7085 0 0 0 0 0 1 [...
|
467 |
|
|
|
468 |
|
|
...] Transmit
|
469 |
|
|
...] bytes packets errs drop fifo colls carrier compressed
|
470 |
|
|
...] 908188 5596 0 0 0 0 0 0
|
471 |
|
|
...] 1375103 17405 0 0 0 0 0 0
|
472 |
|
|
...] 1703981 5535 0 0 0 3 0 0
|
473 |
|
|
|
474 |
|
|
In addition, each Channel Bond interface has it's own directory. For
|
475 |
|
|
example, the bond0 device will have a directory called /proc/net/bond0/.
|
476 |
|
|
It will contain information that is specific to that bond, such as the
|
477 |
|
|
current slaves of the bond, the link status of the slaves, and how
|
478 |
|
|
many times the slaves link has failed.
|
479 |
|
|
|
480 |
|
|
1.5 SCSI info
|
481 |
|
|
-------------
|
482 |
|
|
|
483 |
|
|
If you have a SCSI host adapter in your system, you'll find a subdirectory
|
484 |
|
|
named after the driver for this adapter in /proc/scsi. You'll also see a list
|
485 |
|
|
of all recognized SCSI devices in /proc/scsi:
|
486 |
|
|
|
487 |
|
|
>cat /proc/scsi/scsi
|
488 |
|
|
Attached devices:
|
489 |
|
|
Host: scsi0 Channel: 00 Id: 00 Lun: 00
|
490 |
|
|
Vendor: IBM Model: DGHS09U Rev: 03E0
|
491 |
|
|
Type: Direct-Access ANSI SCSI revision: 03
|
492 |
|
|
Host: scsi0 Channel: 00 Id: 06 Lun: 00
|
493 |
|
|
Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04
|
494 |
|
|
Type: CD-ROM ANSI SCSI revision: 02
|
495 |
|
|
|
496 |
|
|
|
497 |
|
|
The directory named after the driver has one file for each adapter found in
|
498 |
|
|
the system. These files contain information about the controller, including
|
499 |
|
|
the used IRQ and the IO address range. The amount of information shown is
|
500 |
|
|
dependent on the adapter you use. The example shows the output for an Adaptec
|
501 |
|
|
AHA-2940 SCSI adapter:
|
502 |
|
|
|
503 |
|
|
> cat /proc/scsi/aic7xxx/0
|
504 |
|
|
|
505 |
|
|
Adaptec AIC7xxx driver version: 5.1.19/3.2.4
|
506 |
|
|
Compile Options:
|
507 |
|
|
TCQ Enabled By Default : Disabled
|
508 |
|
|
AIC7XXX_PROC_STATS : Disabled
|
509 |
|
|
AIC7XXX_RESET_DELAY : 5
|
510 |
|
|
Adapter Configuration:
|
511 |
|
|
SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
|
512 |
|
|
Ultra Wide Controller
|
513 |
|
|
PCI MMAPed I/O Base: 0xeb001000
|
514 |
|
|
Adapter SEEPROM Config: SEEPROM found and used.
|
515 |
|
|
Adaptec SCSI BIOS: Enabled
|
516 |
|
|
IRQ: 10
|
517 |
|
|
SCBs: Active 0, Max Active 2,
|
518 |
|
|
Allocated 15, HW 16, Page 255
|
519 |
|
|
Interrupts: 160328
|
520 |
|
|
BIOS Control Word: 0x18b6
|
521 |
|
|
Adapter Control Word: 0x005b
|
522 |
|
|
Extended Translation: Enabled
|
523 |
|
|
Disconnect Enable Flags: 0xffff
|
524 |
|
|
Ultra Enable Flags: 0x0001
|
525 |
|
|
Tag Queue Enable Flags: 0x0000
|
526 |
|
|
Ordered Queue Tag Flags: 0x0000
|
527 |
|
|
Default Tag Queue Depth: 8
|
528 |
|
|
Tagged Queue By Device array for aic7xxx host instance 0:
|
529 |
|
|
{255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255}
|
530 |
|
|
Actual queue depth per device for aic7xxx host instance 0:
|
531 |
|
|
{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}
|
532 |
|
|
Statistics:
|
533 |
|
|
(scsi0:0:0:0)
|
534 |
|
|
Device using Wide/Sync transfers at 40.0 MByte/sec, offset 8
|
535 |
|
|
Transinfo settings: current(12/8/1/0), goal(12/8/1/0), user(12/15/1/0)
|
536 |
|
|
Total transfers 160151 (74577 reads and 85574 writes)
|
537 |
|
|
(scsi0:0:6:0)
|
538 |
|
|
Device using Narrow/Sync transfers at 5.0 MByte/sec, offset 15
|
539 |
|
|
Transinfo settings: current(50/15/0/0), goal(50/15/0/0), user(50/15/0/0)
|
540 |
|
|
Total transfers 0 (0 reads and 0 writes)
|
541 |
|
|
|
542 |
|
|
|
543 |
|
|
1.6 Parallel port info in /proc/parport
|
544 |
|
|
---------------------------------------
|
545 |
|
|
|
546 |
|
|
The directory /proc/parport contains information about the parallel ports of
|
547 |
|
|
your system. It has one subdirectory for each port, named after the port
|
548 |
|
|
number (0,1,2,...).
|
549 |
|
|
|
550 |
|
|
These directories contain the four files shown in Table 1-8.
|
551 |
|
|
|
552 |
|
|
|
553 |
|
|
Table 1-8: Files in /proc/parport
|
554 |
|
|
..............................................................................
|
555 |
|
|
File Content
|
556 |
|
|
autoprobe Any IEEE-1284 device ID information that has been acquired.
|
557 |
|
|
devices list of the device drivers using that port. A + will appear by the
|
558 |
|
|
name of the device currently using the port (it might not appear
|
559 |
|
|
against any).
|
560 |
|
|
hardware Parallel port's base address, IRQ line and DMA channel.
|
561 |
|
|
irq IRQ that parport is using for that port. This is in a separate
|
562 |
|
|
file to allow you to alter it by writing a new value in (IRQ
|
563 |
|
|
number or none).
|
564 |
|
|
..............................................................................
|
565 |
|
|
|
566 |
|
|
1.7 TTY info in /proc/tty
|
567 |
|
|
-------------------------
|
568 |
|
|
|
569 |
|
|
Information about the available and actually used tty's can be found in the
|
570 |
|
|
directory /proc/tty.You'll find entries for drivers and line disciplines in
|
571 |
|
|
this directory, as shown in Table 1-9.
|
572 |
|
|
|
573 |
|
|
|
574 |
|
|
Table 1-9: Files in /proc/tty
|
575 |
|
|
..............................................................................
|
576 |
|
|
File Content
|
577 |
|
|
drivers list of drivers and their usage
|
578 |
|
|
ldiscs registered line disciplines
|
579 |
|
|
driver/serial usage statistic and status of single tty lines
|
580 |
|
|
..............................................................................
|
581 |
|
|
|
582 |
|
|
To see which tty's are currently in use, you can simply look into the file
|
583 |
|
|
/proc/tty/drivers:
|
584 |
|
|
|
585 |
|
|
> cat /proc/tty/drivers
|
586 |
|
|
pty_slave /dev/pts 136 0-255 pty:slave
|
587 |
|
|
pty_master /dev/ptm 128 0-255 pty:master
|
588 |
|
|
pty_slave /dev/ttyp 3 0-255 pty:slave
|
589 |
|
|
pty_master /dev/pty 2 0-255 pty:master
|
590 |
|
|
serial /dev/cua 5 64-67 serial:callout
|
591 |
|
|
serial /dev/ttyS 4 64-67 serial
|
592 |
|
|
/dev/tty0 /dev/tty0 4 0 system:vtmaster
|
593 |
|
|
/dev/ptmx /dev/ptmx 5 2 system
|
594 |
|
|
/dev/console /dev/console 5 1 system:console
|
595 |
|
|
/dev/tty /dev/tty 5 0 system:/dev/tty
|
596 |
|
|
unknown /dev/tty 4 1-63 console
|
597 |
|
|
|
598 |
|
|
|
599 |
|
|
------------------------------------------------------------------------------
|
600 |
|
|
Summary
|
601 |
|
|
------------------------------------------------------------------------------
|
602 |
|
|
The /proc file system serves information about the running system. It not only
|
603 |
|
|
allows access to process data but also allows you to request the kernel status
|
604 |
|
|
by reading files in the hierarchy.
|
605 |
|
|
|
606 |
|
|
The directory structure of /proc reflects the types of information and makes
|
607 |
|
|
it easy, if not obvious, where to look for specific data.
|
608 |
|
|
------------------------------------------------------------------------------
|
609 |
|
|
|
610 |
|
|
------------------------------------------------------------------------------
|
611 |
|
|
CHAPTER 2: MODIFYING SYSTEM PARAMETERS
|
612 |
|
|
------------------------------------------------------------------------------
|
613 |
|
|
|
614 |
|
|
------------------------------------------------------------------------------
|
615 |
|
|
In This Chapter
|
616 |
|
|
------------------------------------------------------------------------------
|
617 |
|
|
* Modifying kernel parameters by writing into files found in /proc/sys
|
618 |
|
|
* Exploring the files which modify certain parameters
|
619 |
|
|
* Review of the /proc/sys file tree
|
620 |
|
|
------------------------------------------------------------------------------
|
621 |
|
|
|
622 |
|
|
|
623 |
|
|
A very interesting part of /proc is the directory /proc/sys. This is not only
|
624 |
|
|
a source of information, it also allows you to change parameters within the
|
625 |
|
|
kernel. Be very careful when attempting this. You can optimize your system,
|
626 |
|
|
but you can also cause it to crash. Never alter kernel parameters on a
|
627 |
|
|
production system. Set up a development machine and test to make sure that
|
628 |
|
|
everything works the way you want it to. You may have no alternative but to
|
629 |
|
|
reboot the machine once an error has been made.
|
630 |
|
|
|
631 |
|
|
To change a value, simply echo the new value into the file. An example is
|
632 |
|
|
given below in the section on the file system data. You need to be root to do
|
633 |
|
|
this. You can create your own boot script to perform this every time your
|
634 |
|
|
system boots.
|
635 |
|
|
|
636 |
|
|
The files in /proc/sys can be used to fine tune and monitor miscellaneous and
|
637 |
|
|
general things in the operation of the Linux kernel. Since some of the files
|
638 |
|
|
can inadvertently disrupt your system, it is advisable to read both
|
639 |
|
|
documentation and source before actually making adjustments. In any case, be
|
640 |
|
|
very careful when writing to any of these files. The entries in /proc may
|
641 |
|
|
change slightly between the 2.1.* and the 2.2 kernel, so if there is any doubt
|
642 |
|
|
review the kernel documentation in the directory /usr/src/linux/Documentation.
|
643 |
|
|
This chapter is heavily based on the documentation included in the pre 2.2
|
644 |
|
|
kernels, and became part of it in version 2.2.1 of the Linux kernel.
|
645 |
|
|
|
646 |
|
|
2.1 /proc/sys/fs - File system data
|
647 |
|
|
-----------------------------------
|
648 |
|
|
|
649 |
|
|
This subdirectory contains specific file system, file handle, inode, dentry
|
650 |
|
|
and quota information.
|
651 |
|
|
|
652 |
|
|
Currently, these files are in /proc/sys/fs:
|
653 |
|
|
|
654 |
|
|
dentry-state
|
655 |
|
|
------------
|
656 |
|
|
|
657 |
|
|
Status of the directory cache. Since directory entries are dynamically
|
658 |
|
|
allocated and deallocated, this file indicates the current status. It holds
|
659 |
|
|
six values, in which the last two are not used and are always zero. The others
|
660 |
|
|
are listed in table 2-1.
|
661 |
|
|
|
662 |
|
|
|
663 |
|
|
Table 2-1: Status files of the directory cache
|
664 |
|
|
..............................................................................
|
665 |
|
|
File Content
|
666 |
|
|
nr_dentry Almost always zero
|
667 |
|
|
nr_unused Number of unused cache entries
|
668 |
|
|
age_limit
|
669 |
|
|
in seconds after the entry may be reclaimed, when memory is short
|
670 |
|
|
want_pages internally
|
671 |
|
|
..............................................................................
|
672 |
|
|
|
673 |
|
|
dquot-nr and dquot-max
|
674 |
|
|
----------------------
|
675 |
|
|
|
676 |
|
|
The file dquot-max shows the maximum number of cached disk quota entries.
|
677 |
|
|
|
678 |
|
|
The file dquot-nr shows the number of allocated disk quota entries and the
|
679 |
|
|
number of free disk quota entries.
|
680 |
|
|
|
681 |
|
|
If the number of available cached disk quotas is very low and you have a large
|
682 |
|
|
number of simultaneous system users, you might want to raise the limit.
|
683 |
|
|
|
684 |
|
|
file-nr and file-max
|
685 |
|
|
--------------------
|
686 |
|
|
|
687 |
|
|
The kernel allocates file handles dynamically, but doesn't free them again at
|
688 |
|
|
this time.
|
689 |
|
|
|
690 |
|
|
The value in file-max denotes the maximum number of file handles that the
|
691 |
|
|
Linux kernel will allocate. When you get a lot of error messages about running
|
692 |
|
|
out of file handles, you might want to raise this limit. The default value is
|
693 |
|
|
4096. To change it, just write the new number into the file:
|
694 |
|
|
|
695 |
|
|
# cat /proc/sys/fs/file-max
|
696 |
|
|
4096
|
697 |
|
|
# echo 8192 > /proc/sys/fs/file-max
|
698 |
|
|
# cat /proc/sys/fs/file-max
|
699 |
|
|
8192
|
700 |
|
|
|
701 |
|
|
|
702 |
|
|
This method of revision is useful for all customizable parameters of the
|
703 |
|
|
kernel - simply echo the new value to the corresponding file.
|
704 |
|
|
|
705 |
|
|
The three values in file-nr denote the number of allocated file handles, the
|
706 |
|
|
number of used file handles, and the maximum number of file handles. When the
|
707 |
|
|
allocated file handles come close to the maximum, but the number of actually
|
708 |
|
|
used ones is far behind, you've encountered a peak in your usage of file
|
709 |
|
|
handles and you don't need to increase the maximum.
|
710 |
|
|
|
711 |
|
|
inode-state and inode-nr
|
712 |
|
|
------------------------
|
713 |
|
|
|
714 |
|
|
The file inode-nr contains the first two items from inode-state, so we'll skip
|
715 |
|
|
to that file...
|
716 |
|
|
|
717 |
|
|
inode-state contains two actual numbers and five dummy values. The numbers
|
718 |
|
|
are nr_inodes and nr_free_inodes (in order of appearance).
|
719 |
|
|
|
720 |
|
|
nr_inodes
|
721 |
|
|
~~~~~~~~~
|
722 |
|
|
|
723 |
|
|
Denotes the number of inodes the system has allocated. This number will
|
724 |
|
|
grow and shrink dynamically.
|
725 |
|
|
|
726 |
|
|
nr_free_inodes
|
727 |
|
|
--------------
|
728 |
|
|
|
729 |
|
|
Represents the number of free inodes. Ie. The number of inuse inodes is
|
730 |
|
|
(nr_inodes - nr_free_inodes).
|
731 |
|
|
|
732 |
|
|
super-nr and super-max
|
733 |
|
|
----------------------
|
734 |
|
|
|
735 |
|
|
Again, super block structures are allocated by the kernel, but not freed. The
|
736 |
|
|
file super-max contains the maximum number of super block handlers, where
|
737 |
|
|
super-nr shows the number of currently allocated ones.
|
738 |
|
|
|
739 |
|
|
Every mounted file system needs a super block, so if you plan to mount lots of
|
740 |
|
|
file systems, you may want to increase these numbers.
|
741 |
|
|
|
742 |
|
|
2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
|
743 |
|
|
-----------------------------------------------------------
|
744 |
|
|
|
745 |
|
|
Besides these files, there is the subdirectory /proc/sys/fs/binfmt_misc. This
|
746 |
|
|
handles the kernel support for miscellaneous binary formats.
|
747 |
|
|
|
748 |
|
|
Binfmt_misc provides the ability to register additional binary formats to the
|
749 |
|
|
Kernel without compiling an additional module/kernel. Therefore, binfmt_misc
|
750 |
|
|
needs to know magic numbers at the beginning or the filename extension of the
|
751 |
|
|
binary.
|
752 |
|
|
|
753 |
|
|
It works by maintaining a linked list of structs that contain a description of
|
754 |
|
|
a binary format, including a magic with size (or the filename extension),
|
755 |
|
|
offset and mask, and the interpreter name. On request it invokes the given
|
756 |
|
|
interpreter with the original program as argument, as binfmt_java and
|
757 |
|
|
binfmt_em86 and binfmt_mz do. Since binfmt_misc does not define any default
|
758 |
|
|
binary-formats, you have to register an additional binary-format.
|
759 |
|
|
|
760 |
|
|
There are two general files in binfmt_misc and one file per registered format.
|
761 |
|
|
The two general files are register and status.
|
762 |
|
|
|
763 |
|
|
Registering a new binary format
|
764 |
|
|
-------------------------------
|
765 |
|
|
|
766 |
|
|
To register a new binary format you have to issue the command
|
767 |
|
|
|
768 |
|
|
echo :name:type:offset:magic:mask:interpreter: > /proc/sys/fs/binfmt_misc/register
|
769 |
|
|
|
770 |
|
|
|
771 |
|
|
|
772 |
|
|
with appropriate name (the name for the /proc-dir entry), offset (defaults to
|
773 |
|
|
0, if omitted), magic, mask (which can be omitted, defaults to all 0xff) and
|
774 |
|
|
last but not least, the interpreter that is to be invoked (for example and
|
775 |
|
|
testing /bin/echo). Type can be M for usual magic matching or E for filename
|
776 |
|
|
extension matching (give extension in place of magic).
|
777 |
|
|
|
778 |
|
|
Check or reset the status of the binary format handler
|
779 |
|
|
------------------------------------------------------
|
780 |
|
|
|
781 |
|
|
If you do a cat on the file /proc/sys/fs/binfmt_misc/status, you will get the
|
782 |
|
|
current status (enabled/disabled) of binfmt_misc. Change the status by echoing
|
783 |
|
|
|
784 |
|
|
registered binary formats) to status. For example echo 0 > status to disable
|
785 |
|
|
binfmt_misc (temporarily).
|
786 |
|
|
|
787 |
|
|
Status of a single handler
|
788 |
|
|
--------------------------
|
789 |
|
|
|
790 |
|
|
Each registered handler has an entry in /proc/sys/fs/binfmt_misc. These files
|
791 |
|
|
perform the same function as status, but their scope is limited to the actual
|
792 |
|
|
binary format. By cating this file, you also receive all related information
|
793 |
|
|
about the interpreter/magic of the binfmt.
|
794 |
|
|
|
795 |
|
|
Example usage of binfmt_misc (emulate binfmt_java)
|
796 |
|
|
--------------------------------------------------
|
797 |
|
|
|
798 |
|
|
cd /proc/sys/fs/binfmt_misc
|
799 |
|
|
echo ':Java:M::\xca\xfe\xba\xbe::/usr/local/java/bin/javawrapper:' > register
|
800 |
|
|
echo ':HTML:E::html::/usr/local/java/bin/appletviewer:' > register
|
801 |
|
|
echo ':Applet:M::
|