* Documentation/proc.txt update
@ 2000-11-12 23:32 Jorge Nerin
2000-11-13 1:14 ` Jorge Nerin
0 siblings, 1 reply; 4+ messages in thread
From: Jorge Nerin @ 2000-11-12 23:32 UTC (permalink / raw)
To: bb, Linux Kernel Mailing List
Hello, this is a patch with some updates to the Documetation/proc.txt
file, basically it contains updates to the new files in /proc/<PID>, new
files in /proc, and a paragraph about /proc/sys/net/ipv4/tcp_ecn. It's
far from complete, but it's a start point.
--- old/proc.txt Mon Oct 23 15:20:00 2000
+++ new/proc.txt Mon Nov 13 00:20:24 2000
@@ -46,7 +46,7 @@
the SuSE Linux distribution. As there is no complete documentation
for the
/proc file system and we've used many freely available sources to
write these
chapters, it seems only fair to give the work back to the Linux
community.
-This work is based on the 2.2.* kernel version. I'm afraid it's still
far from
+This work is based on the 2.2.* kernel version and the upcomming 2.4.*.
I'm afraid it's still far from
complete, but we hope it will be useful. As far as we know, it is
the first
'all-in-one' document about the /proc file system. It is focused on
the Intel
x86 hardware, so if you are looking for PPC, ARM, SPARC, APX, etc.,
features,
@@ -92,7 +92,7 @@
The proc file system acts as an interface to internal data structures
in the
kernel. It can be used to obtain information about the system and to
change
-certain kernel parameters at runtime.
+certain kernel parameters at runtime (sysctl).
First, we'll take a look at the read-only parts of /proc. In
Chapter 2, we
show you how you can use /proc/sys to change settings.
@@ -111,16 +111,17 @@
..............................................................................
File Content
cmdline Command line arguments
- environ Values of environment variables
+ cpu Current and last cpu in wich it was executed (2.4)(smp)
+ cwd Link to the Current Working Directory
+ environ Values of environment variables
+ exe Link to the executable in the filesystem
fd Directory, which contains all file descriptors
+ maps Maps to executables and library files (2.4)
mem Memory held by this process
+ root Link to the root directory of this process
stat Process status
- status Process status in human readable form
- cwd Link to the current working directory
- exe Link to the executable of this process
- maps Memory maps
- root Link to the root directory of this process
statm Process memory status information
+ status Process status in human readable form
..............................................................................
For example, to get the status information of a process, all you have
to do is
@@ -131,6 +132,7 @@
State: R (running)
Pid: 5452
PPid: 743
+ TracerPid: 0 (2.4)
Uid: 501 501 501 501
Gid: 100 100 100 100
Groups: 100 14 16
@@ -187,13 +189,20 @@
devices Available devices (block and character)
dma Used DMS channels
filesystems Supported filesystems
+ driver Various drivers grouped here, currently rtc (2.4)
+ execdomains Execdomains, related to security (2.4)
+ fb Frame Buffer devices (2.4)
+ fs File system parameters, currently nfs/exports (2.4)
ide Directory containing info about the IDE subsystem
interrupts Interrupt usage
+ iomem Memory map (2.4)
ioports I/O port usage
- kcore Kernel core image (can be ELF or A.OUT)
+ irq Masks for irq to cpu affinity (2.4)(smp?)
+ isapnp ISA PnP (Plug&Play) Info (2.4)
+ kcore Kernel core image (can be ELF or A.OUT(depreciated in
2.4))
kmsg Kernel messages
ksyms Kernel symbol table
- loadavg Load average
+ loadavg Load average of last 1, 5 & 15 minutes
locks Kernel locks
meminfo Memory info
misc Miscellaneous
@@ -201,14 +210,19 @@
mounts Mounted filesystems
net Networking info (see text)
partitions Table of partitions known to the system
+ pci Depreciated info of PCI bus (new way -> /proc/bus/pci/,
+ decoupled by lspci (2.4)
rtc Real time clock
scsi SCSI info (see text)
slabinfo Slab pool info
stat Overall statistics
swaps Swap space utilization
sys See chapter 2
+ sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4)
+ tty Info of tty drivers
uptime System uptime
version Kernel version
+ video bttv info of video resources (2.4)
..............................................................................
You can, for example, check which interrupts are currently in use
and what
@@ -230,6 +244,68 @@
15: 7 XT-PIC ide1
NMI: 0
+In 2.4.* a couple of lines where added to this file LOC & ERR (this
time is the
+output of a SMP machine):
+
+ > cat /proc/interrupts
+
+ CPU0 CPU1
+ 0: 1243498 1214548 IO-APIC-edge timer
+ 1: 8949 8958 IO-APIC-edge keyboard
+ 2: 0 0 XT-PIC cascade
+ 5: 11286 10161 IO-APIC-edge soundblaster
+ 8: 1 0 IO-APIC-edge rtc
+ 9: 27422 27407 IO-APIC-edge 3c503
+ 12: 113645 113873 IO-APIC-edge PS/2 Mouse
+ 13: 0 0 XT-PIC fpu
+ 14: 22491 24012 IO-APIC-edge ide0
+ 15: 2183 2415 IO-APIC-edge ide1
+ 17: 30564 30414 IO-APIC-level eth0
+ 18: 177 164 IO-APIC-level bttv
+ NMI: 2457961 2457959
+ LOC: 2457882 2457881
+ ERR: 2155
+
+NMI is incremented in this case because every timer interrupt generates
a NMI
+(Non Maskable Interrupt) which is used by the NMI Watchdog to detect
lookups.
+
+LOC is the local interrupt counter of the internal APIC of every CPU.
+
+ERR is incremented in the case of errors in the IO-APIC bus (the bus
that
+connects the CPUs in a SMP system. This means that an error has been
detected,
+the IO-APIC automatically retry the transmision, so it should not be a
big
+problem, but you should read the SMP-FAQ.
+
+In this context it could be interesting to note the new irq directory
in 2.4.
+It could be used to set IRQ to CPU affinity, this means that you can
"hook" an
+IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents
of the
+irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask
+
+For example
+ > ls /proc/irq/
+ 0 10 12 14 16 18 2 4 6 8 prof_cpu_mask
+ 1 11 13 15 17 19 3 5 7 9
+ > ls /proc/irq/0/
+ smp_affinity
+
+The contents of the prof_cpu_mask file and each smp_affinity file for
each IRQ
+is the same by default:
+
+ > cat /proc/irq/0/smp_affinity
+ ffffffff
+
+It's a bitmask, in wich you can specify wich CPUs can handle the IRQ,
you can
+set it by doing:
+
+ > echo 1 > /proc/irq/prof_cpu_mask
+
+This means that only the first CPU will handle the IRQ, but you can
also echo 5
+wich means that only the first and fourth CPU can handle the IRQ.
+
+The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
+between all the CPUs which are allowed to handle it. As usual the
kernel has
+more info than you and does a better job than you, so the defaults are
the
+best choice for almost everyone.
There are three more important subdirectories in /proc: net, scsi,
and sys.
The general rule is that the contents, or even the existence
of these
@@ -1306,6 +1382,15 @@
TCP settings
------------
+
+tcp_ecn
+-------
+
+This file controls the use of the ECN bit in the IPv4 headers, this is
a new
+feature about Explicit Congestion Notification, but some routers and
firewalls
+block trafic that has this bit set, so it could be necessary to echo 0
to
+/proc/sys/net/ipv4/tcp_ecn, if you want to talk to this sites. For more
info
+you could read RFC2481.
tcp_retrans_collapse
--------------------
--
Jorge Nerin
<comandante@zaralinux.com>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Documentation/proc.txt update 2000-11-12 23:32 Documentation/proc.txt update Jorge Nerin @ 2000-11-13 1:14 ` Jorge Nerin 2000-11-14 23:11 ` Jorge Nerin 0 siblings, 1 reply; 4+ messages in thread From: Jorge Nerin @ 2000-11-13 1:14 UTC (permalink / raw) To: Linux Kernel Mailing List [-- Attachment #1: Type: text/plain, Size: 443 bytes --] Jorge Nerin wrote: > > Hello, this is a patch with some updates to the Documetation/proc.txt > file, basically it contains updates to the new files in /proc/<PID>, new > files in /proc, and a paragraph about /proc/sys/net/ipv4/tcp_ecn. It's > far from complete, but it's a start point. > Well, netscape seems to wrap long lines, as Peter Samuelson noticed me, so I send it again as an attachment. -- Jorge Nerin <comandante@zaralinux.com> [-- Attachment #2: Documentation.proc.txt.patch --] [-- Type: text/plain, Size: 8530 bytes --] --- old/proc.txt Mon Oct 23 15:20:00 2000 +++ new/proc.txt Mon Nov 13 00:20:24 2000 @@ -46,7 +46,7 @@ the SuSE Linux distribution. As there is no complete documentation for the /proc file system and we've used many freely available sources to write these chapters, it seems only fair to give the work back to the Linux community. -This work is based on the 2.2.* kernel version. I'm afraid it's still far from +This work is based on the 2.2.* kernel version and the upcomming 2.4.*. I'm afraid it's still far from complete, but we hope it will be useful. As far as we know, it is the first 'all-in-one' document about the /proc file system. It is focused on the Intel x86 hardware, so if you are looking for PPC, ARM, SPARC, APX, etc., features, @@ -92,7 +92,7 @@ The proc file system acts as an interface to internal data structures in the kernel. It can be used to obtain information about the system and to change -certain kernel parameters at runtime. +certain kernel parameters at runtime (sysctl). First, we'll take a look at the read-only parts of /proc. In Chapter 2, we show you how you can use /proc/sys to change settings. @@ -111,16 +111,17 @@ .............................................................................. File Content cmdline Command line arguments - environ Values of environment variables + cpu Current and last cpu in wich it was executed (2.4)(smp) + cwd Link to the Current Working Directory + environ Values of environment variables + exe Link to the executable in the filesystem fd Directory, which contains all file descriptors + maps Maps to executables and library files (2.4) mem Memory held by this process + root Link to the root directory of this process stat Process status - status Process status in human readable form - cwd Link to the current working directory - exe Link to the executable of this process - maps Memory maps - root Link to the root directory of this process statm Process memory status information + status Process status in human readable form .............................................................................. For example, to get the status information of a process, all you have to do is @@ -131,6 +132,7 @@ State: R (running) Pid: 5452 PPid: 743 + TracerPid: 0 (2.4) Uid: 501 501 501 501 Gid: 100 100 100 100 Groups: 100 14 16 @@ -187,13 +189,20 @@ devices Available devices (block and character) dma Used DMS channels filesystems Supported filesystems + driver Various drivers grouped here, currently rtc (2.4) + execdomains Execdomains, related to security (2.4) + fb Frame Buffer devices (2.4) + fs File system parameters, currently nfs/exports (2.4) ide Directory containing info about the IDE subsystem interrupts Interrupt usage + iomem Memory map (2.4) ioports I/O port usage - kcore Kernel core image (can be ELF or A.OUT) + irq Masks for irq to cpu affinity (2.4)(smp?) + isapnp ISA PnP (Plug&Play) Info (2.4) + kcore Kernel core image (can be ELF or A.OUT(depreciated in 2.4)) kmsg Kernel messages ksyms Kernel symbol table - loadavg Load average + loadavg Load average of last 1, 5 & 15 minutes locks Kernel locks meminfo Memory info misc Miscellaneous @@ -201,14 +210,19 @@ mounts Mounted filesystems net Networking info (see text) partitions Table of partitions known to the system + pci Depreciated info of PCI bus (new way -> /proc/bus/pci/, + decoupled by lspci (2.4) rtc Real time clock scsi SCSI info (see text) slabinfo Slab pool info stat Overall statistics swaps Swap space utilization sys See chapter 2 + sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4) + tty Info of tty drivers uptime System uptime version Kernel version + video bttv info of video resources (2.4) .............................................................................. You can, for example, check which interrupts are currently in use and what @@ -230,6 +244,68 @@ 15: 7 XT-PIC ide1 NMI: 0 +In 2.4.* a couple of lines where added to this file LOC & ERR (this time is the +output of a SMP machine): + + > cat /proc/interrupts + + CPU0 CPU1 + 0: 1243498 1214548 IO-APIC-edge timer + 1: 8949 8958 IO-APIC-edge keyboard + 2: 0 0 XT-PIC cascade + 5: 11286 10161 IO-APIC-edge soundblaster + 8: 1 0 IO-APIC-edge rtc + 9: 27422 27407 IO-APIC-edge 3c503 + 12: 113645 113873 IO-APIC-edge PS/2 Mouse + 13: 0 0 XT-PIC fpu + 14: 22491 24012 IO-APIC-edge ide0 + 15: 2183 2415 IO-APIC-edge ide1 + 17: 30564 30414 IO-APIC-level eth0 + 18: 177 164 IO-APIC-level bttv + NMI: 2457961 2457959 + LOC: 2457882 2457881 + ERR: 2155 + +NMI is incremented in this case because every timer interrupt generates a NMI +(Non Maskable Interrupt) which is used by the NMI Watchdog to detect lookups. + +LOC is the local interrupt counter of the internal APIC of every CPU. + +ERR is incremented in the case of errors in the IO-APIC bus (the bus that +connects the CPUs in a SMP system. This means that an error has been detected, +the IO-APIC automatically retry the transmision, so it should not be a big +problem, but you should read the SMP-FAQ. + +In this context it could be interesting to note the new irq directory in 2.4. +It could be used to set IRQ to CPU affinity, this means that you can "hook" an +IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the +irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask + +For example + > ls /proc/irq/ + 0 10 12 14 16 18 2 4 6 8 prof_cpu_mask + 1 11 13 15 17 19 3 5 7 9 + > ls /proc/irq/0/ + smp_affinity + +The contents of the prof_cpu_mask file and each smp_affinity file for each IRQ +is the same by default: + + > cat /proc/irq/0/smp_affinity + ffffffff + +It's a bitmask, in wich you can specify wich CPUs can handle the IRQ, you can +set it by doing: + + > echo 1 > /proc/irq/prof_cpu_mask + +This means that only the first CPU will handle the IRQ, but you can also echo 5 +wich means that only the first and fourth CPU can handle the IRQ. + +The way IRQs are routed is handled by the IO-APIC, and it's Round Robin +between all the CPUs which are allowed to handle it. As usual the kernel has +more info than you and does a better job than you, so the defaults are the +best choice for almost everyone. There are three more important subdirectories in /proc: net, scsi, and sys. The general rule is that the contents, or even the existence of these @@ -1306,6 +1382,15 @@ TCP settings ------------ + +tcp_ecn +------- + +This file controls the use of the ECN bit in the IPv4 headers, this is a new +feature about Explicit Congestion Notification, but some routers and firewalls +block trafic that has this bit set, so it could be necessary to echo 0 to +/proc/sys/net/ipv4/tcp_ecn, if you want to talk to this sites. For more info +you could read RFC2481. tcp_retrans_collapse -------------------- ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Documentation/proc.txt update 2000-11-13 1:14 ` Jorge Nerin @ 2000-11-14 23:11 ` Jorge Nerin 2000-11-15 14:39 ` Jorge Nerin 0 siblings, 1 reply; 4+ messages in thread From: Jorge Nerin @ 2000-11-14 23:11 UTC (permalink / raw) To: Linux Kernel Mailing List Jorge Nerin wrote: > > Jorge Nerin wrote: > > > > Hello, this is a patch with some updates to the Documetation/proc.txt > > file, basically it contains updates to the new files in /proc/<PID>, new > > files in /proc, and a paragraph about /proc/sys/net/ipv4/tcp_ecn. It's > > far from complete, but it's a start point. > > > > Well, netscape seems to wrap long lines, as Peter Samuelson noticed me, > so I send it again as an attachment. > > -- > Jorge Nerin > <comandante@zaralinux.com> Another little update to the patch, this time with bits from Philipp Matthias Hahn, and a little formating change to break a very long line in the middle of a paragraph. -- Jorge Nerin <comandante@zaralinux.com> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Documentation/proc.txt update 2000-11-14 23:11 ` Jorge Nerin @ 2000-11-15 14:39 ` Jorge Nerin 0 siblings, 0 replies; 4+ messages in thread From: Jorge Nerin @ 2000-11-15 14:39 UTC (permalink / raw) To: Linux Kernel Mailing List Jorge Nerin wrote: > > Jorge Nerin wrote: > > > > Jorge Nerin wrote: > > > > > > Hello, this is a patch with some updates to the Documetation/proc.txt > > > file, basically it contains updates to the new files in /proc/<PID>, new > > > files in /proc, and a paragraph about /proc/sys/net/ipv4/tcp_ecn. It's > > > far from complete, but it's a start point. > > > > > > > Well, netscape seems to wrap long lines, as Peter Samuelson noticed me, > > so I send it again as an attachment. > > > > -- > > Jorge Nerin > > <comandante@zaralinux.com> > > Another little update to the patch, this time with bits from Philipp > Matthias Hahn, and a little formating change to break a very long line > in the middle of a paragraph. > > -- > Jorge Nerin > <comandante@zaralinux.com> > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > Please read the FAQ at http://www.tux.org/lkml/ I have to be more careful, I don't know if I forgot to attach the file or if the majordomo has dropped it?, probably the first one. So again, the update: (let's hope it doesn't wrap) --- old/proc.txt Mon Oct 23 15:20:00 2000 +++ new/proc.txt Wed Nov 15 00:04:48 2000 @@ -3,8 +3,11 @@ ------------------------------------------------------------------------------ /proc/sys Terrehon Bowden <terrehon@pacbell.net> October 7 1999 Bodo Bauer <bb@ricochet.net> + +2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000 ------------------------------------------------------------------------------ -Version 1.2 Kernel version 2.2.12 +Version 1.3 Kernel version 2.2.12 + Kernel version 2.4.0-test11-pre4 ------------------------------------------------------------------------------ Table of Contents @@ -42,17 +45,18 @@ 0.1 Introduction/Credits ------------------------ -This documentation is part of a soon (or so we hope) to be released book on -the SuSE Linux distribution. As there is no complete documentation for the -/proc file system and we've used many freely available sources to write these -chapters, it seems only fair to give the work back to the Linux community. -This work is based on the 2.2.* kernel version. I'm afraid it's still far from -complete, but we hope it will be useful. As far as we know, it is the first -'all-in-one' document about the /proc file system. It is focused on the Intel -x86 hardware, so if you are looking for PPC, ARM, SPARC, APX, etc., features, -you probably won't find what you are looking for. It also only covers IPv4 -networking, not IPv6 nor other protocols - sorry. But additions and patches -are welcome and will be added to this document if you mail them to Bodo. +This documentation is part of a soon (or so we hope) to be released book on +the SuSE Linux distribution. As there is no complete documentation for the +/proc file system and we've used many freely available sources to write these +chapters, it seems only fair to give the work back to the Linux community. +This work is based on the 2.2.* kernel version and the upcomming 2.4.*. I'm +afraid it's still far from complete, but we hope it will be useful. As far as +we know, it is the first 'all-in-one' document about the /proc file system. It +is focused on the Intel x86 hardware, so if you are looking for PPC, ARM, +SPARC, APX, etc., features, you probably won't find what you are looking for. +It also only covers IPv4 networking, not IPv6 nor other protocols - sorry. But +additions and patches are welcome and will be added to this document if you +mail them to Bodo. We'd like to thank Alan Cox, Rik van Riel, and Alexey Kuznetsov and a lot of other people for help compiling this documentation. We'd also like to extend a @@ -65,9 +69,13 @@ contact Bodo Bauer at bb@ricochet.net. We'll be happy to add them to this document. -The latest version of this document is available online at +The latest version of this document is available online at http://skaro.nightcrawler.com/~bb/Docs/Proc as HTML version. +If the above direction does not works for you, ypu could try the kernel +mailing list at linux-kernel@vger.kernel.org and/or try to reach me at +comandante@zaralinux.com. + 0.2 Legal Stuff --------------- @@ -92,7 +100,7 @@ The proc file system acts as an interface to internal data structures in the kernel. It can be used to obtain information about the system and to change -certain kernel parameters at runtime. +certain kernel parameters at runtime (sysctl). First, we'll take a look at the read-only parts of /proc. In Chapter 2, we show you how you can use /proc/sys to change settings. @@ -111,16 +119,17 @@ .............................................................................. File Content cmdline Command line arguments - environ Values of environment variables + cpu Current and last cpu in wich it was executed (2.4)(smp) + cwd Link to the current working directory + environ Values of environment variables + exe Link to the executable of this process fd Directory, which contains all file descriptors + maps Memory maps to executables and library files (2.4) mem Memory held by this process + root Link to the root directory of this process stat Process status - status Process status in human readable form - cwd Link to the current working directory - exe Link to the executable of this process - maps Memory maps - root Link to the root directory of this process statm Process memory status information + status Process status in human readable form .............................................................................. For example, to get the status information of a process, all you have to do is @@ -131,6 +140,7 @@ State: R (running) Pid: 5452 PPid: 743 + TracerPid: 0 (2.4) Uid: 501 501 501 501 Gid: 100 100 100 100 Groups: 100 14 16 @@ -187,13 +197,20 @@ devices Available devices (block and character) dma Used DMS channels filesystems Supported filesystems + driver Various drivers grouped here, currently rtc (2.4) + execdomains Execdomains, related to security (2.4) + fb Frame Buffer devices (2.4) + fs File system parameters, currently nfs/exports (2.4) ide Directory containing info about the IDE subsystem interrupts Interrupt usage + iomem Memory map (2.4) ioports I/O port usage - kcore Kernel core image (can be ELF or A.OUT) + irq Masks for irq to cpu affinity (2.4)(smp?) + isapnp ISA PnP (Plug&Play) Info (2.4) + kcore Kernel core image (can be ELF or A.OUT(deprecated in 2.4)) kmsg Kernel messages ksyms Kernel symbol table - loadavg Load average + loadavg Load average of last 1, 5 & 15 minutes locks Kernel locks meminfo Memory info misc Miscellaneous @@ -201,14 +218,19 @@ mounts Mounted filesystems net Networking info (see text) partitions Table of partitions known to the system + pci Depreciated info of PCI bus (new way -> /proc/bus/pci/, + decoupled by lspci (2.4) rtc Real time clock scsi SCSI info (see text) slabinfo Slab pool info stat Overall statistics swaps Swap space utilization sys See chapter 2 + sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4) + tty Info of tty drivers uptime System uptime version Kernel version + video bttv info of video resources (2.4) .............................................................................. You can, for example, check which interrupts are currently in use and what @@ -230,6 +252,68 @@ 15: 7 XT-PIC ide1 NMI: 0 +In 2.4.* a couple of lines where added to this file LOC & ERR (this time is the +output of a SMP machine): + + > cat /proc/interrupts + + CPU0 CPU1 + 0: 1243498 1214548 IO-APIC-edge timer + 1: 8949 8958 IO-APIC-edge keyboard + 2: 0 0 XT-PIC cascade + 5: 11286 10161 IO-APIC-edge soundblaster + 8: 1 0 IO-APIC-edge rtc + 9: 27422 27407 IO-APIC-edge 3c503 + 12: 113645 113873 IO-APIC-edge PS/2 Mouse + 13: 0 0 XT-PIC fpu + 14: 22491 24012 IO-APIC-edge ide0 + 15: 2183 2415 IO-APIC-edge ide1 + 17: 30564 30414 IO-APIC-level eth0 + 18: 177 164 IO-APIC-level bttv + NMI: 2457961 2457959 + LOC: 2457882 2457881 + ERR: 2155 + +NMI is incremented in this case because every timer interrupt generates a NMI +(Non Maskable Interrupt) which is used by the NMI Watchdog to detect lookups. + +LOC is the local interrupt counter of the internal APIC of every CPU. + +ERR is incremented in the case of errors in the IO-APIC bus (the bus that +connects the CPUs in a SMP system. This means that an error has been detected, +the IO-APIC automatically retry the transmision, so it should not be a big +problem, but you should read the SMP-FAQ. + +In this context it could be interesting to note the new irq directory in 2.4. +It could be used to set IRQ to CPU affinity, this means that you can "hook" an +IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the +irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask + +For example + > ls /proc/irq/ + 0 10 12 14 16 18 2 4 6 8 prof_cpu_mask + 1 11 13 15 17 19 3 5 7 9 + > ls /proc/irq/0/ + smp_affinity + +The contents of the prof_cpu_mask file and each smp_affinity file for each IRQ +is the same by default: + + > cat /proc/irq/0/smp_affinity + ffffffff + +It's a bitmask, in wich you can specify wich CPUs can handle the IRQ, you can +set it by doing: + + > echo 1 > /proc/irq/prof_cpu_mask + +This means that only the first CPU will handle the IRQ, but you can also echo 5 +wich means that only the first and fourth CPU can handle the IRQ. + +The way IRQs are routed is handled by the IO-APIC, and it's Round Robin +between all the CPUs which are allowed to handle it. As usual the kernel has +more info than you and does a better job than you, so the defaults are the +best choice for almost everyone. There are three more important subdirectories in /proc: net, scsi, and sys. The general rule is that the contents, or even the existence of these @@ -1306,6 +1390,15 @@ TCP settings ------------ + +tcp_ecn +------- + +This file controls the use of the ECN bit in the IPv4 headers, this is a new +feature about Explicit Congestion Notification, but some routers and firewalls +block trafic that has this bit set, so it could be necessary to echo 0 to +/proc/sys/net/ipv4/tcp_ecn, if you want to talk to this sites. For more info +you could read RFC2481. tcp_retrans_collapse -------------------- -- Jorge Nerin <comandante@zaralinux.com> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2000-11-16 0:20 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2000-11-12 23:32 Documentation/proc.txt update Jorge Nerin 2000-11-13 1:14 ` Jorge Nerin 2000-11-14 23:11 ` Jorge Nerin 2000-11-15 14:39 ` Jorge Nerin
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