diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/removed/raw1394_legacy_isochronous | 16 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 11 | ||||
| -rw-r--r-- | Documentation/block/barrier.txt | 16 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 18 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 43 | ||||
| -rw-r--r-- | Documentation/networking/00-INDEX | 3 | ||||
| -rw-r--r-- | Documentation/networking/sk98lin.txt | 568 | ||||
| -rw-r--r-- | Documentation/networking/spider_net.txt | 204 | ||||
| -rw-r--r-- | Documentation/power_supply_class.txt | 167 | ||||
| -rw-r--r-- | Documentation/sched-design-CFS.txt | 119 |
10 files changed, 520 insertions, 645 deletions
diff --git a/Documentation/ABI/removed/raw1394_legacy_isochronous b/Documentation/ABI/removed/raw1394_legacy_isochronous new file mode 100644 index 000000000000..1b629622d883 --- /dev/null +++ b/Documentation/ABI/removed/raw1394_legacy_isochronous @@ -0,0 +1,16 @@ +What: legacy isochronous ABI of raw1394 (1st generation iso ABI) +Date: June 2007 (scheduled), removed in kernel v2.6.23 +Contact: linux1394-devel@lists.sourceforge.net +Description: + The two request types RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN have + been deprecated for quite some time. They are very inefficient as they + come with high interrupt load and several layers of callbacks for each + packet. Because of these deficiencies, the video1394 and dv1394 drivers + and the 3rd-generation isochronous ABI in raw1394 (rawiso) were created. + +Users: + libraw1394 users via the long deprecated API raw1394_iso_write, + raw1394_start_iso_write, raw1394_start_iso_rcv, raw1394_stop_iso_rcv + + libdc1394, which optionally uses these old libraw1394 calls + alternatively to the more efficient video1394 ABI diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index 38f88b6ae405..8c5698a8c2e1 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -643,4 +643,15 @@ X!Idrivers/video/console/fonts.c !Edrivers/spi/spi.c </chapter> + <chapter id="splice"> + <title>splice API</title> + <para>) + splice is a method for moving blocks of data around inside the + kernel, without continually transferring it between the kernel + and user space. + </para> +!Iinclude/linux/splice.h +!Ffs/splice.c + </chapter> + </book> diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt index a272c3db8094..7d279f2f5bb2 100644 --- a/Documentation/block/barrier.txt +++ b/Documentation/block/barrier.txt @@ -82,23 +82,12 @@ including draining and flushing. typedef void (prepare_flush_fn)(request_queue_t *q, struct request *rq); int blk_queue_ordered(request_queue_t *q, unsigned ordered, - prepare_flush_fn *prepare_flush_fn, - unsigned gfp_mask); - -int blk_queue_ordered_locked(request_queue_t *q, unsigned ordered, - prepare_flush_fn *prepare_flush_fn, - unsigned gfp_mask); - -The only difference between the two functions is whether or not the -caller is holding q->queue_lock on entry. The latter expects the -caller is holding the lock. + prepare_flush_fn *prepare_flush_fn); @q : the queue in question @ordered : the ordered mode the driver/device supports @prepare_flush_fn : this function should prepare @rq such that it flushes cache to physical medium when executed -@gfp_mask : gfp_mask used when allocating data structures - for ordered processing For example, SCSI disk driver's prepare_flush_fn looks like the following. @@ -106,9 +95,10 @@ following. static void sd_prepare_flush(request_queue_t *q, struct request *rq) { memset(rq->cmd, 0, sizeof(rq->cmd)); - rq->flags |= REQ_BLOCK_PC; + rq->cmd_type = REQ_TYPE_BLOCK_PC; rq->timeout = SD_TIMEOUT; rq->cmd[0] = SYNCHRONIZE_CACHE; + rq->cmd_len = 10; } The following seven ordered modes are supported. The following table diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 7d3f205b0ba5..3a159dac04f5 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -49,16 +49,6 @@ Who: Adrian Bunk <bunk@stusta.de> --------------------------- -What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN -When: June 2007 -Why: Deprecated in favour of the more efficient and robust rawiso interface. - Affected are applications which use the deprecated part of libraw1394 - (raw1394_iso_write, raw1394_start_iso_write, raw1394_start_iso_rcv, - raw1394_stop_iso_rcv) or bypass libraw1394. -Who: Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de> - ---------------------------- - What: old NCR53C9x driver When: October 2007 Why: Replaced by the much better esp_scsi driver. Actual low-level @@ -258,14 +248,6 @@ Who: Len Brown <len.brown@intel.com> --------------------------- -What: sk98lin network driver -When: July 2007 -Why: In kernel tree version of driver is unmaintained. Sk98lin driver - replaced by the skge driver. -Who: Stephen Hemminger <shemminger@osdl.org> - ---------------------------- - What: Compaq touchscreen device emulation When: Oct 2007 Files: drivers/input/tsdev.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index af50f9bbe68e..4d880b3d1f35 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1014,49 +1014,6 @@ and is between 256 and 4096 characters. It is defined in the file mga= [HW,DRM] - migration_cost= - [KNL,SMP] debug: override scheduler migration costs - Format: <level-1-usecs>,<level-2-usecs>,... - This debugging option can be used to override the - default scheduler migration cost matrix. The numbers - are indexed by 'CPU domain distance'. - E.g. migration_cost=1000,2000,3000 on an SMT NUMA - box will set up an intra-core migration cost of - 1 msec, an inter-core migration cost of 2 msecs, - and an inter-node migration cost of 3 msecs. - - WARNING: using the wrong values here can break - scheduler performance, so it's only for scheduler - development purposes, not production environments. - - migration_debug= - [KNL,SMP] migration cost auto-detect verbosity - Format=<0|1|2> - If a system's migration matrix reported at bootup - seems erroneous then this option can be used to - increase verbosity of the detection process. - We default to 0 (no extra messages), 1 will print - some more information, and 2 will be really - verbose (probably only useful if you also have a - serial console attached to the system). - - migration_factor= - [KNL,SMP] multiply/divide migration costs by a factor - Format=<percent> - This debug option can be used to proportionally - increase or decrease the auto-detected migration - costs for all entries of the migration matrix. - E.g. migration_factor=150 will increase migration - costs by 50%. (and thus the scheduler will be less - eager migrating cache-hot tasks) - migration_factor=80 will decrease migration costs - by 20%. (thus the scheduler will be more eager to - migrate tasks) - - WARNING: using the wrong values here can break - scheduler performance, so it's only for scheduler - development purposes, not production environments. - mousedev.tap_time= [MOUSE] Maximum time between finger touching and leaving touchpad surface for touch to be considered diff --git a/Documentation/networking/00-INDEX b/Documentation/networking/00-INDEX index 153d84d281e6..d63f480afb74 100644 --- a/Documentation/networking/00-INDEX +++ b/Documentation/networking/00-INDEX @@ -96,9 +96,6 @@ routing.txt - the new routing mechanism shaper.txt - info on the module that can shape/limit transmitted traffic. -sk98lin.txt - - Marvell Yukon Chipset / SysKonnect SK-98xx compliant Gigabit - Ethernet Adapter family driver info skfp.txt - SysKonnect FDDI (SK-5xxx, Compaq Netelligent) driver info. smc9.txt diff --git a/Documentation/networking/sk98lin.txt b/Documentation/networking/sk98lin.txt deleted file mode 100644 index 8590a954df1d..000000000000 --- a/Documentation/networking/sk98lin.txt +++ /dev/null @@ -1,568 +0,0 @@ -(C)Copyright 1999-2004 Marvell(R). -All rights reserved -=========================================================================== - -sk98lin.txt created 13-Feb-2004 - -Readme File for sk98lin v6.23 -Marvell Yukon/SysKonnect SK-98xx Gigabit Ethernet Adapter family driver for LINUX - -This file contains - 1 Overview - 2 Required Files - 3 Installation - 3.1 Driver Installation - 3.2 Inclusion of adapter at system start - 4 Driver Parameters - 4.1 Per-Port Parameters - 4.2 Adapter Parameters - 5 Large Frame Support - 6 VLAN and Link Aggregation Support (IEEE 802.1, 802.1q, 802.3ad) - 7 Troubleshooting - -=========================================================================== - - -1 Overview -=========== - -The sk98lin driver supports the Marvell Yukon and SysKonnect -SK-98xx/SK-95xx compliant Gigabit Ethernet Adapter on Linux. It has -been tested with Linux on Intel/x86 machines. -*** - - -2 Required Files -================= - -The linux kernel source. -No additional files required. -*** - - -3 Installation -=============== - -It is recommended to download the latest version of the driver from the -SysKonnect web site www.syskonnect.com. If you have downloaded the latest -driver, the Linux kernel has to be patched before the driver can be -installed. For details on how to patch a Linux kernel, refer to the -patch.txt file. - -3.1 Driver Installation ------------------------- - -The following steps describe the actions that are required to install -the driver and to start it manually. These steps should be carried -out for the initial driver setup. Once confirmed to be ok, they can -be included in the system start. - -NOTE 1: To perform the following tasks you need 'root' access. - -NOTE 2: In case of problems, please read the section "Troubleshooting" - below. - -The driver can either be integrated into the kernel or it can be compiled -as a module. Select the appropriate option during the kernel -configuration. - -Compile/use the driver as a module ----------------------------------- -To compile the driver, go to the directory /usr/src/linux and -execute the command "make menuconfig" or "make xconfig" and proceed as -follows: - -To integrate the driver permanently into the kernel, proceed as follows: - -1. Select the menu "Network device support" and then "Ethernet(1000Mbit)" -2. Mark "Marvell Yukon Chipset / SysKonnect SK-98xx family support" - with (*) -3. Build a new kernel when the configuration of the above options is - finished. -4. Install the new kernel. -5. Reboot your system. - -To use the driver as a module, proceed as follows: - -1. Enable 'loadable module support' in the kernel. -2. For automatic driver start, enable the 'Kernel module loader'. -3. Select the menu "Network device support" and then "Ethernet(1000Mbit)" -4. Mark "Marvell Yukon Chipset / SysKonnect SK-98xx family support" - with (M) -5. Execute the command "make modules". -6. Execute the command "make modules_install". - The appropriate modules will be installed. -7. Reboot your system. - - -Load the module manually ------------------------- -To load the module manually, proceed as follows: - -1. Enter "modprobe sk98lin". -2. If a Marvell Yukon or SysKonnect SK-98xx adapter is installed in - your computer and you have a /proc file system, execute the command: - "ls /proc/net/sk98lin/" - This should produce an output containing a line with the following - format: - eth0 eth1 ... - which indicates that your adapter has been found and initialized. - - NOTE 1: If you have more than one Marvell Yukon or SysKonnect SK-98xx - adapter installed, the adapters will be listed as 'eth0', - 'eth1', 'eth2', etc. - For each adapter, repeat steps 3 and 4 below. - - NOTE 2: If you have other Ethernet adapters installed, your Marvell - Yukon or SysKonnect SK-98xx adapter will be mapped to the - next available number, e.g. 'eth1'. The mapping is executed - automatically. - The module installation message (displayed either in a system - log file or on the console) prints a line for each adapter - found containing the corresponding 'ethX'. - -3. Select an IP address and assign it to the respective adapter by - entering: - ifconfig eth0 <ip-address> - With this command, the adapter is connected to the Ethernet. - - SK-98xx Gigabit Ethernet Server Adapters: The yellow LED on the adapter - is now active, the link status LED of the primary port is active and - the link status LED of the secondary port (on dual port adapters) is - blinking (if the ports are connected to a switch or hub). - SK-98xx V2.0 Gigabit Ethernet Adapters: The link status LED is active. - In addition, you will receive a status message on the console stating - "ethX: network connection up using port Y" and showing the selected - connection parameters (x stands for the ethernet device number - (0,1,2, etc), y stands for the port name (A or B)). - - NOTE: If you are in doubt about IP addresses, ask your network - administrator for assistance. - -4. Your adapter should now be fully operational. - Use 'ping <otherstation>' to verify the connection to other computers - on your network. -5. To check the adapter configuration view /proc/net/sk98lin/[devicename]. - For example by executing: - "cat /proc/net/sk98lin/eth0" - -Unload the module ------------------ -To stop and unload the driver modules, proceed as follows: - -1. Execute the command "ifconfig eth0 down". -2. Execute the command "rmmod sk98lin". - -3.2 Inclusion of adapter at system start ------------------------------------------ - -Since a large number of different Linux distributions are -available, we are unable to describe a general installation procedure -for the driver module. -Because the driver is now integrated in the kernel, installation should -be easy, using the standard mechanism of your distribution. -Refer to the distribution's manual for installation of ethernet adapters. - -*** - -4 Driver Parameters -==================== - -Parameters can be set at the command line after the module has been -loaded with the command 'modprobe'. -In some distributions, the configuration tools are able to pass parameters -to the driver module. - -If you use the kernel module loader, you can set driver parameters -in the file /etc/modprobe.conf (or /etc/modules.conf in 2.4 or earlier). -To set the driver parameters in this file, proceed as follows: - -1. Insert a line of the form : - options sk98lin ... - For "...", the same syntax is required as described for the command - line parameters of modprobe below. -2. To activate the new parameters, either reboot your computer - or - unload and reload the driver. - The syntax of the driver parameters is: - - modprobe sk98lin parameter=value1[,value2[,value3...]] - - where value1 refers to the first adapter, value2 to the second etc. - -NOTE: All parameters are case sensitive. Write them exactly as shown - below. - -Example: -Suppose you have two adapters. You want to set auto-negotiation -on the first adapter to ON and on the second adapter to OFF. -You also want to set DuplexCapabilities on the first adapter -to FULL, and on the second adapter to HALF. -Then, you must enter: - - modprobe sk98lin AutoNeg_A=On,Off DupCap_A=Full,Half - -NOTE: The number of adapters that can be configured this way is - limited in the driver (file skge.c, constant SK_MAX_CARD_PARAM). - The current limit is 16. If you happen to install - more adapters, adjust this and recompile. - - -4.1 Per-Port Parameters ------------------------- - -These settings are available for each port on the adapter. -In the following description, '?' stands for the port for -which you set the parameter (A or B). - -Speed ------ -Parameter: Speed_? -Values: 10, 100, 1000, Auto -Default: Auto - -This parameter is used to set the speed capabilities. It is only valid -for the SK-98xx V2.0 copper adapters. -Usually, the speed is negotiated between the two ports during link -establishment. If this fails, a port can be forced to a specific setting -with this parameter. - -Auto-Negotiation ----------------- -Parameter: AutoNeg_? -Values: On, Off, Sense -Default: On - -The "Sense"-mode automatically detects whether the link partner supports -auto-negotiation or not. - -Duplex Capabilities -------------------- -Parameter: DupCap_? -Values: Half, Full, Both -Default: Both - -This parameters is only relevant if auto-negotiation for this port is -not set to "Sense". If auto-negotiation is set to "On", all three values -are possible. If it is set to "Off", only "Full" and "Half" are allowed. -This parameter is useful if your link partner does not support all -possible combinations. - -Flow Control ------------- -Parameter: FlowCtrl_? -Values: Sym, SymOrRem, LocSend, None -Default: SymOrRem - -This parameter can be used to set the flow control capabilities the -port reports during auto-negotiation. It can be set for each port -individually. -Possible modes: - -- Sym = Symmetric: both link partners are allowed to send - PAUSE frames - -- SymOrRem = SymmetricOrRemote: both or only remote partner - are allowed to send PAUSE frames - -- LocSend = LocalSend: only local link partner is allowed - to send PAUSE frames - -- None = no link partner is allowed to send PAUSE frames - -NOTE: This parameter is ignored if auto-negotiation is set to "Off". - -Role in Master-Slave-Negotiation (1000Base-T only) --------------------------------------------------- -Parameter: Role_? -Values: Auto, Master, Slave -Default: Auto - -This parameter is only valid for the SK-9821 and SK-9822 adapters. -For two 1000Base-T ports to communicate, one must take the role of the -master (providing timing information), while the other must be the -slave. Usually, this is negotiated between the two ports during link -establishment. If this fails, a port can be forced to a specific setting -with this parameter. - - -4.2 Adapter Parameters ------------------------ - -Connection Type (SK-98xx V2.0 copper adapters only) ---------------- -Parameter: ConType -Values: Auto, 100FD, 100HD, 10FD, 10HD -Default: Auto - -The parameter 'ConType' is a combination of all five per-port parameters -within one single parameter. This simplifies the configuration of both ports -of an adapter card! The different values of this variable reflect the most -meaningful combinations of port parameters. - -The following table shows the values of 'ConType' and the corresponding -combinations of the per-port parameters: - - ConType | DupCap AutoNeg FlowCtrl Role Speed - ----------+------------------------------------------------------ - Auto | Both On SymOrRem Auto Auto - 100FD | Full Off None Auto (ignored) 100 - 100HD | Half Off None Auto (ignored) 100 - 10FD | Full Off None Auto (ignored) 10 - 10HD | Half Off None Auto (ignored) 10 - -Stating any other port parameter together with this 'ConType' variable -will result in a merged configuration of those settings. This due to -the fact, that the per-port parameters (e.g. Speed_? ) have a higher -priority than the combined variable 'ConType'. - -NOTE: This parameter is always used on both ports of the adapter card. - -Interrupt Moderation --------------------- -Parameter: Moderation -Values: None, Static, Dynamic -Default: None - -Interrupt moderation is employed to limit the maximum number of interrupts -the driver has to serve. That is, one or more interrupts (which indicate any -transmit or receive packet to be processed) are queued until the driver -processes them. When queued interrupts are to be served, is determined by the -'IntsPerSec' parameter, which is explained later below. - -Possible modes: - - -- None - No interrupt moderation is applied on the adapter card. - Therefore, each transmit or receive interrupt is served immediately - as soon as it appears on the interrupt line of the adapter card. - - -- Static - Interrupt moderation is applied on the adapter card. - All transmit and receive interrupts are queued until a complete - moderation interval ends. If such a moderation interval ends, all - queued interrupts are processed in one big bunch without any delay. - The term 'static' reflects the fact, that interrupt moderation is - always enabled, regardless how much network load is currently - passing via a particular interface. In addition, the duration of - the moderation interval has a fixed length that never changes while - the driver is operational. - - -- Dynamic - Interrupt moderation might be applied on the adapter card, - depending on the load of the system. If the driver detects that the - system load is too high, the driver tries to shield the system against - too much network load by enabling interrupt moderation. If - at a later - time - the CPU utilization decreases again (or if the network load is - negligible) the interrupt moderation will automatically be disabled. - -Interrupt moderation should be used when the driver has to handle one or more -interfaces with a high network load, which - as a consequence - leads also to a -high CPU utilization. When moderation is applied in such high network load -situations, CPU load might be reduced by 20-30%. - -NOTE: The drawback of using interrupt moderation is an increase of the round- -trip-time (RTT), due to the queueing and serving of interrupts at dedicated -moderation times. - -Interrupts per second ---------------------- -Parameter: IntsPerSec -Values: 30...40000 (interrupts per second) -Default: 2000 - -This parameter is only used if either static or dynamic interrupt moderation -is used on a network adapter card. Using this parameter if no moderation is -applied will lead to no action performed. - -This parameter determines the length of any interrupt moderation interval. -Assuming that static interrupt moderation is to be used, an 'IntsPerSec' -parameter value of 2000 will lead to an interrupt moderation interval of -500 microseconds. - -NOTE: The duration of the moderation interval is to be chosen with care. -At first glance, selecting a very long duration (e.g. only 100 interrupts per -second) seems to be meaningful, but the increase of packet-processing delay -is tremendous. On the other hand, selecting a very short moderation time might -compensate the use of any moderation being applied. - - -Preferred Port --------------- -Parameter: PrefPort -Values: A, B -Default: A - -This is used to force the preferred port to A or B (on dual-port network -adapters). The preferred port is the one that is used if both are detected -as fully functional. - -RLMT Mode (Redundant Link Management Technology) ------------------------------------------------- -Parameter: RlmtMode -Values: CheckLinkState,CheckLocalPort, CheckSeg, DualNet -Default: CheckLinkState - -RLMT monitors the status of the port. If the link of the active port -fails, RLMT switches immediately to the standby link. The virtual link is -maintained as long as at least one 'physical' link is up. - -Possible modes: - - -- CheckLinkState - Check link state only: RLMT uses the link state - reported by the adapter hardware for each individual port to - determine whether a port can be used for all network traffic or - not. - - -- CheckLocalPort - In this mode, RLMT monitors the network path - between the two ports of an adapter by regularly exchanging packets - between them. This mode requires a network configuration in which - the two ports are able to "see" each other (i.e. there must not be - any router between the ports). - - -- CheckSeg - Check local port and segmentation: This mode supports the - same functions as the CheckLocalPort mode and additionally checks - network segmentation between the ports. Therefore, this mode is only - to be used if Gigabit Ethernet switches are installed on the network - that have been configured to use the Spanning Tree protocol. - - -- DualNet - In this mode, ports A and B are used as separate devices. - If you have a dual port adapter, port A will be configured as eth0 - and port B as eth1. Both ports can be used independently with - distinct IP addresses. The preferred port setting is not used. - RLMT is turned off. - -NOTE: RLMT modes CLP and CLPSS are designed to operate in configurations - where a network path between the ports on one adapter exists. - Moreover, they are not designed to work where adapters are connected - back-to-back. -*** - - -5 Large Frame Support -====================== - -The driver supports large frames (also called jumbo frames). Using large -frames can result in an improved throughput if transferring large amounts -of data. -To enable large frames, set the MTU (maximum transfer unit) of the -interface to the desired value (up to 9000), execute the following -command: - ifconfig eth0 mtu 9000 -This will only work if you have two adapters connected back-to-back -or if you use a switch that supports large frames. When using a switch, -it should be configured to allow large frames and auto-negotiation should -be set to OFF. The setting must be configured on all adapters that can be -reached by the large frames. If one adapter is not set to receive large -frames, it will simply drop them. - -You can switch back to the standard ethernet frame size by executing the -following command: - ifconfig eth0 mtu 1500 - -To permanently configure this setting, add a script with the 'ifconfig' -line to the system startup sequence (named something like "S99sk98lin" -in /etc/rc.d/rc2.d). -*** - - -6 VLAN and Link Aggregation Support (IEEE 802.1, 802.1q, 802.3ad) -================================================================== - -The Marvell Yukon/SysKonnect Linux drivers are able to support VLAN and -Link Aggregation according to IEEE standards 802.1, 802.1q, and 802.3ad. -These features are only available after installation of open source -modules available on the Internet: -For VLAN go to: http://www.candelatech.com/~greear/vlan.html -For Link Aggregation go to: http://www.st.rim.or.jp/~yumo - -NOTE: SysKonnect GmbH does not offer any support for these open source - modules and does not take the responsibility for any kind of - failures or problems arising in connection with these modules. - -NOTE: Configuring Link Aggregation on a SysKonnect dual link adapter may - cause problems when unloading the driver. - - -7 Troubleshooting -================== - -If any problems occur during the installation process, check the -following list: - - -Problem: The SK-98xx adapter cannot be found by the driver. -Solution: In /proc/pci search for the following entry: - 'Ethernet controller: SysKonnect SK-98xx ...' - If this entry exists, the SK-98xx or SK-98xx V2.0 adapter has - been found by the system and should be operational. - If this entry does not exist or if the file '/proc/pci' is not - found, there may be a hardware problem or the PCI support may - not be enabled in your kernel. - The adapter can be checked using the diagnostics program which - is available on the SysKonnect web site: - www.syskonnect.com - - Some COMPAQ machines have problems dealing with PCI under Linux. - This problem is described in the 'PCI howto' document - (included in some distributions or available from the - web, e.g. at 'www.linux.org'). - - -Problem: Programs such as 'ifconfig' or 'route' cannot be found or the - error message 'Operation not permitted' is displayed. -Reason: You are not logged in as user 'root'. -Solution: Logout and login as 'root' or change to 'root' via 'su'. - - -Problem: Upon use of the command 'ping <address>' the message - "ping: sendto: Network is unreachable" is displayed. -Reason: Your route is not set correctly. -Solution: If you are using RedHat, you probably forgot to set up the - route in the 'network configuration'. - Check the existing routes with the 'route' command and check - if an entry for 'eth0' exists, and if so, if it is set correctly. - - -Problem: The driver can be started, the adapter is connected to the - network, but you cannot receive or transmit any packets; - e.g. 'ping' does not work. -Reason: There is an incorrect route in your routing table. -Solution: Check the routing table with the command 'route' and read the - manual help pages dealing with routes (enter 'man route'). - -NOTE: Although the 2.2.x kernel versions generate the routing entry - automatically, problems of this kind may occur here as well. We've - come across a situation in which the driver started correctly at - system start, but after the driver has been removed and reloaded, - the route of the adapter's network pointed to the 'dummy0'device - and had to be corrected manually. - - -Problem: Your computer should act as a router between multiple - IP subnetworks (using multiple adapters), but computers in - other subnetworks cannot be reached. -Reason: Either the router's kernel is not configured for IP forwarding - or the routing table and gateway configuration of at least one - computer is not working. - -Problem: Upon driver start, the following error message is displayed: - "eth0: -- ERROR -- - Class: internal Software error - Nr: 0xcc - Msg: SkGeInitPort() cannot init running ports" -Reason: You are using a driver compiled for single processor machines - on a multiprocessor machine with SMP (Symmetric MultiProcessor) - kernel. -Solution: Configure your kernel appropriately and recompile the kernel or - the modules. - - - -If your problem is not listed here, please contact SysKonnect's technical -support for help (linux@syskonnect.de). -When contacting our technical support, please ensure that the following -information is available: -- System Manufacturer and HW Informations (CPU, Memory... ) -- PCI-Boards in your system -- Distribution -- Kernel version -- Driver version -*** - - - -***End of Readme File*** diff --git a/Documentation/networking/spider_net.txt b/Documentation/networking/spider_net.txt new file mode 100644 index 000000000000..4b4adb8eb14f --- /dev/null +++ b/Documentation/networking/spider_net.txt @@ -0,0 +1,204 @@ + + The Spidernet Device Driver + =========================== + +Written by Linas Vepstas <linas@austin.ibm.com> + +Version of 7 June 2007 + +Abstract +======== +This document sketches the structure of portions of the spidernet +device driver in the Linux kernel tree. The spidernet is a gigabit +ethernet device built into the Toshiba southbridge commonly used +in the SONY Playstation 3 and the IBM QS20 Cell blade. + +The Structure of the RX Ring. +============================= +The receive (RX) ring is a circular linked list of RX descriptors, +together with three pointers into the ring that are used to manage its +contents. + +The elements of the ring are called "descriptors" or "descrs"; they +describe the received data. This includes a pointer to a buffer +containing the received data, the buffer size, and various status bits. + +There are three primary states that a descriptor can be in: "empty", +"full" and "not-in-use". An "empty" or "ready" descriptor is ready +to receive data from the hardware. A "full" descriptor has data in it, +and is waiting to be emptied and processed by the OS. A "not-in-use" +descriptor is neither empty or full; it is simply not ready. It may +not even have a data buffer in it, or is otherwise unusable. + +During normal operation, on device startup, the OS (specifically, the +spidernet device driver) allocates a set of RX descriptors and RX +buffers. These are all marked "empty", ready to receive data. This +ring is handed off to the hardware, which sequentially fills in the +buffers, and marks them "full". The OS follows up, taking the full +buffers, processing them, and re-marking them empty. + +This filling and emptying is managed by three pointers, the "head" +and "tail" pointers, managed by the OS, and a hardware current +descriptor pointer (GDACTDPA). The GDACTDPA points at the descr +currently being filled. When this descr is filled, the hardware +marks it full, and advances the GDACTDPA by one. Thus, when there is +flowing RX traffic, every descr behind it should be marked "full", +and everything in front of it should be "empty". If the hardware +discovers that the current descr is not empty, it will signal an +interrupt, and halt processing. + +The tail pointer tails or trails the hardware pointer. When the +hardware is ahead, the tail pointer will be pointing at a "full" +descr. The OS will process this descr, and then mark it "not-in-use", +and advance the tail pointer. Thus, when there is flowing RX traffic, +all of the descrs in front of the tail pointer should be "full", and +all of those behind it should be "not-in-use". When RX traffic is not +flowing, then the tail pointer can catch up to the hardware pointer. +The OS will then note that the current tail is "empty", and halt +processing. + +The head pointer (somewhat mis-named) follows after the tail pointer. +When traffic is flowing, then the head pointer will be pointing at +a "not-in-use" descr. The OS will perform various housekeeping duties +on this descr. This includes allocating a new data buffer and +dma-mapping it so as to make it visible to the hardware. The OS will +then mark the descr as "empty", ready to receive data. Thus, when there +is flowing RX traffic, everything in front of the head pointer should +be "not-in-use", and everything behind it should be "empty". If no +RX traffic is flowing, then the head pointer can catch up to the tail +pointer, at which point the OS will notice that the head descr is +"empty", and it will halt processing. + +Thus, in an idle system, the GDACTDPA, tail and head pointers will +all be pointing at the same descr, which should be "empty". All of the +other descrs in the ring should be "empty" as well. + +The show_rx_chain() routine will print out the the locations of the +GDACTDPA, tail and head pointers. It will also summarize the contents +of the ring, starting at the tail pointer, and listing the status +of the descrs that follow. + +A typical example of the output, for a nearly idle system, might be + +net eth1: Total number of descrs=256 +net eth1: Chain tail located at descr=20 +net eth1: Chain head is at 20 +net eth1: HW curr desc (GDACTDPA) is at 21 +net eth1: Have 1 descrs with stat=x40800101 +net eth1: HW next desc (GDACNEXTDA) is at 22 +net eth1: Last 255 descrs with stat=xa0800000 + +In the above, the hardware has filled in one descr, number 20. Both +head and tail are pointing at 20, because it has not yet been emptied. +Meanwhile, hw is pointing at 21, which is free. + +The "Have nnn decrs" refers to the descr starting at the tail: in this +case, nnn=1 descr, starting at descr 20. The "Last nnn descrs" refers +to all of the rest of the descrs, from the last status change. The "nnn" +is a count of how many descrs have exactly the same status. + +The status x4... corresponds to "full" and status xa... corresponds +to "empty". The actual value printed is RXCOMST_A. + +In the device driver source code, a different set of names are +used for these same concepts, so that + +"empty" == SPIDER_NET_DESCR_CARDOWNED == 0xa +"full" == SPIDER_NET_DESCR_FRAME_END == 0x4 +"not in use" == SPIDER_NET_DESCR_NOT_IN_USE == 0xf + + +The RX RAM full bug/feature +=========================== + +As long as the OS can empty out the RX buffers at a rate faster than +the hardware can fill them, there is no problem. If, for some reason, +the OS fails to empty the RX ring fast enough, the hardware GDACTDPA +pointer will catch up to the head, notice the not-empty condition, +ad stop. However, RX packets may still continue arriving on the wire. +The spidernet chip can save some limited number of these in local RAM. +When this local ram fills up, the spider chip will issue an interrupt +indicating this (GHIINT0STS will show ERRINT, and the GRMFLLINT bit +will be set in GHIINT1STS). When the RX ram full condition occurs, +a certain bug/feature is triggered that has to be specially handled. +This section describes the special handling for this condition. + +When the OS finally has a chance to run, it will empty out the RX ring. +In particular, it will clear the descriptor on which the hardware had +stopped. However, once the hardware has decided that a certain +descriptor is invalid, it will not restart at that descriptor; instead +it will restart at the next descr. This potentially will lead to a +deadlock condition, as the tail pointer will be pointing at this descr, +which, from the OS point of view, is empty; the OS will be waiting for +this descr to be filled. However, the hardware has skipped this descr, +and is filling the next descrs. Since the OS doesn't see this, there +is a potential deadlock, with the OS waiting for one descr to fill, +while the hardware is waiting for a different set of descrs to become +empty. + +A call to show_rx_chain() at this point indicates the nature of the +problem. A typical print when the network is hung shows the following: + +net eth1: Spider RX RAM full, incoming packets might be discarded! +net eth1: Total number of descrs=256 +net eth1: Chain tail located at descr=255 +net eth1: Chain head is at 255 +net eth1: HW curr desc (GDACTDPA) is at 0 +net eth1: Have 1 descrs with stat=xa0800000 +net eth1: HW next desc (GDACNEXTDA) is at 1 +net eth1: Have 127 descrs with stat=x40800101 +net eth1: Have 1 descrs with stat=x40800001 +net eth1: Have 126 descrs with stat=x40800101 +net eth1: Last 1 descrs with stat=xa0800000 + +Both the tail and head pointers are pointing at descr 255, which is +marked xa... which is "empty". Thus, from the OS point of view, there +is nothing to be done. In particular, there is the implicit assumption +that everything in front of the "empty" descr must surely also be empty, +as explained in the last section. The OS is waiting for descr 255 to +become non-empty, which, in this case, will never happen. + +The HW pointer is at descr 0. This descr is marked 0x4.. or "full". +Since its already full, the hardware can do nothing more, and thus has +halted processing. Notice that descrs 0 through 254 are all marked +"full", while descr 254 and 255 are empty. (The "Last 1 descrs" is +descr 254, since tail was at 255.) Thus, the system is deadlocked, +and there can be no forward progress; the OS thinks there's nothing +to do, and the hardware has nowhere to put incoming data. + +This bug/feature is worked around with the spider_net_resync_head_ptr() +routine. When the driver receives RX interrupts, but an examination +of the RX chain seems to show it is empty, then it is probable that +the hardware has skipped a descr or two (sometimes dozens under heavy +network conditions). The spider_net_resync_head_ptr() subroutine will +search the ring for the next full descr, and the driver will resume +operations there. Since this will leave "holes" in the ring, there +is also a spider_net_resync_tail_ptr() that will skip over such holes. + +As of this writing, the spider_net_resync() strategy seems to work very +well, even under heavy network loads. + + +The TX ring +=========== +The TX ring uses a low-watermark interrupt scheme to make sure that +the TX queue is appropriately serviced for large packet sizes. + +For packet sizes greater than about 1KBytes, the kernel can fill +the TX ring quicker than the device can drain it. Once the ring +is full, the netdev is stopped. When there is room in the ring, +the netdev needs to be reawakened, so that more TX packets are placed +in the ring. The hardware can empty the ring about four times per jiffy, +so its not appropriate to wait for the poll routine to refill, since +the poll routine runs only once per jiffy. The low-watermark mechanism +marks a descr about 1/4th of the way from the bottom of the queue, so +that an interrupt is generated when the descr is processed. This +interrupt wakes up the netdev, which can then refill the queue. +For large packets, this mechanism generates a relatively small number +of interrupts, about 1K/sec. For smaller packets, this will drop to zero +interrupts, as the hardware can empty the queue faster than the kernel +can fill it. + + + ======= END OF DOCUMENT ======== + diff --git a/Documentation/power_supply_class.txt b/Documentation/power_supply_class.txt new file mode 100644 index 000000000000..9758cf433c06 --- /dev/null +++ b/Documentation/power_supply_class.txt @@ -0,0 +1,167 @@ +Linux power supply class +======================== + +Synopsis +~~~~~~~~ +Power supply class used to represent battery, UPS, AC or DC power supply +properties to user-space. + +It defines core set of attributes, which should be applicable to (almost) +every power supply out there. Attributes are available via sysfs and uevent +interfaces. + +Each attribute has well defined meaning, up to unit of measure used. While +the attributes provided are believed to be universally applicable to any +power supply, specific monitoring hardware may not be able to provide them +all, so any of them may be skipped. + +Power supply class is extensible, and allows to define drivers own attributes. +The core attribute set is subject to the standard Linux evolution (i.e. +if it will be found that some attribute is applicable to many power supply +types or their drivers, it can be added to the core set). + +It also integrates with LED framework, for the purpose of providing +typically expected feedback of battery charging/fully charged status and +AC/USB power supply online status. (Note that specific details of the +indication (including whether to use it at all) are fully controllable by +user and/or specific machine defaults, per design principles of LED +framework). + + +Attributes/properties +~~~~~~~~~~~~~~~~~~~~~ +Power supply class has predefined set of attributes, this eliminates code +duplication across drivers. Power supply class insist on reusing its +predefined attributes *and* their units. + +So, userspace gets predictable set of attributes and their units for any +kind of power supply, and can process/present them to a user in consistent +manner. Results for different power supplies and machines are also directly +comparable. + +See drivers/power/ds2760_battery.c and drivers/power/pda_power.c for the +example how to declare and handle attributes. + + +Units +~~~~~ +Quoting include/linux/power_supply.h: + + All voltages, currents, charges, energies, time and temperatures in µV, + µA, µAh, µWh, seconds and tenths of degree Celsius unless otherwise + stated. It's driver's job to convert its raw values to units in which + this class operates. + + +Attributes/properties detailed +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +~ ~ ~ ~ ~ ~ ~ Charge/Energy/Capacity - how to not confuse ~ ~ ~ ~ ~ ~ ~ +~ ~ +~ Because both "charge" (µAh) and "energy" (µWh) represents "capacity" ~ +~ of battery, this class distinguish these terms. Don't mix them! ~ +~ ~ +~ CHARGE_* attributes represents capacity in µAh only. ~ +~ ENERGY_* attributes represents capacity in µWh only. ~ +~ CAPACITY attribute represents capacity in *percents*, from 0 to 100. ~ +~ ~ +~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ + +Postfixes: +_AVG - *hardware* averaged value, use it if your hardware is really able to +report averaged values. +_NOW - momentary/instantaneous values. + +STATUS - this attribute represents operating status (charging, full, +discharging (i.e. powering a load), etc.). This corresponds to +BATTERY_STATUS_* values, as defined in battery.h. + +HEALTH - represents health of the battery, values corresponds to +POWER_SUPPLY_HEALTH_*, defined in battery.h. + +VOLTAGE_MAX_DESIGN, VOLTAGE_MIN_DESIGN - design values for maximal and +minimal power supply voltages. Maximal/minimal means values of voltages +when battery considered "full"/"empty" at normal conditions. Yes, there is +no direct relation between voltage and battery capacity, but some dumb +batteries use voltage for very approximated calculation of capacity. +Battery driver also can use this attribute just to inform userspace +about maximal and minimal voltage thresholds of a given battery. + +CHARGE_FULL_DESIGN, CHARGE_EMPTY_DESIGN - design charge values, when +battery considered full/empty. + +ENERGY_FULL_DESIGN, ENERGY_EMPTY_DESIGN - same as above but for energy. + +CHARGE_FULL, CHARGE_EMPTY - These attributes means "last remembered value +of charge when battery became full/empty". It also could mean "value of +charge when battery considered full/empty at given conditions (temperature, +age)". I.e. these attributes represents real thresholds, not design values. + +ENERGY_FULL, ENERGY_EMPTY - same as above but for energy. + +CAPACITY - capacity in percents. +CAPACITY_LEVEL - capacity level. This corresponds to +POWER_SUPPLY_CAPACITY_LEVEL_*. + +TEMP - temperature of the power supply. +TEMP_AMBIENT - ambient temperature. + +TIME_TO_EMPTY - seconds left for battery to be considered empty (i.e. +while battery powers a load) +TIME_TO_FULL - seconds left for battery to be considered full (i.e. +while battery is charging) + + +Battery <-> external power supply interaction +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Often power supplies are acting as supplies and supplicants at the same +time. Batteries are good example. So, batteries usually care if they're +externally powered or not. + +For that case, power supply class implements notification mechanism for +batteries. + +External power supply (AC) lists supplicants (batteries) names in +"supplied_to" struct member, and each power_supply_changed() call +issued by external power supply will notify supplicants via +external_power_changed callback. + + +QA +~~ +Q: Where is POWER_SUPPLY_PROP_XYZ attribute? +A: If you cannot find attribute suitable for your driver needs, feel free + to add it and send patch along with your driver. + + The attributes available currently are the ones currently provided by the + drivers written. + + Good candidates to add in future: model/part#, cycle_time, manufacturer, + etc. + + +Q: I have some very specific attribute (e.g. battery color), should I add + this attribute to standard ones? +A: Most likely, no. Such attribute can be placed in the driver itself, if + it is useful. Of course, if the attribute in question applicable to + large set of batteries, provided by many drivers, and/or comes from + some general battery specification/standard, it may be a candidate to + be added to the core attribute set. + + +Q: Suppose, my battery monitoring chip/firmware does not provides capacity + in percents, but provides charge_{now,full,empty}. Should I calculate + percentage capacity manually, inside the driver, and register CAPACITY + attribute? The same question about time_to_empty/time_to_full. +A: Most likely, no. This class is designed to export properties which are + directly measurable by the specific hardware available. + + Inferring not available properties using some heuristics or mathematical + model is not subject of work for a battery driver. Such functionality + should be factored out, and in fact, apm_power, the driver to serve + legacy APM API on top of power supply class, uses a simple heuristic of + approximating remaining battery capacity based on its charge, current, + voltage and so on. But full-fledged battery model is likely not subject + for kernel at all, as it would require floating point calculation to deal + with things like differential equations and Kalman filters. This is + better be handled by batteryd/libbattery, yet to be written. diff --git a/Documentation/sched-design-CFS.txt b/Documentation/sched-design-CFS.txt new file mode 100644 index 000000000000..16feebb7bdc0 --- /dev/null +++ b/Documentation/sched-design-CFS.txt @@ -0,0 +1,119 @@ + +This is the CFS scheduler. + +80% of CFS's design can be summed up in a single sentence: CFS basically +models an "ideal, precise multi-tasking CPU" on real hardware. + +"Ideal multi-tasking CPU" is a (non-existent :-)) CPU that has 100% +physical power and which can run each task at precise equal speed, in +parallel, each at 1/nr_running speed. For example: if there are 2 tasks +running then it runs each at 50% physical power - totally in parallel. + +On real hardware, we can run only a single task at once, so while that +one task runs, the other tasks that are waiting for the CPU are at a +disadvantage - the current task gets an unfair amount of CPU time. In +CFS this fairness imbalance is expressed and tracked via the per-task +p->wait_runtime (nanosec-unit) value. "wait_runtime" is the amount of +time the task should now run on the CPU for it to become completely fair +and balanced. + +( small detail: on 'ideal' hardware, the p->wait_runtime value would + always be zero - no task would ever get 'out of balance' from the + 'ideal' share of CPU time. ) + +CFS's task picking logic is based on this p->wait_runtime value and it +is thus very simple: it always tries to run the task with the largest +p->wait_runtime value. In other words, CFS tries to run the task with +the 'gravest need' for more CPU time. So CFS always tries to split up +CPU time between runnable tasks as close to 'ideal multitasking +hardware' as possible. + +Most of the rest of CFS's design just falls out of this really simple +concept, with a few add-on embellishments like nice levels, +multiprocessing and various algorithm variants to recognize sleepers. + +In practice it works like this: the system runs a task a bit, and when +the task schedules (or a scheduler tick happens) the task's CPU usage is +'accounted for': the (small) time it just spent using the physical CPU +is deducted from p->wait_runtime. [minus the 'fair share' it would have +gotten anyway]. Once p->wait_runtime gets low enough so that another +task becomes the 'leftmost task' of the time-ordered rbtree it maintains +(plus a small amount of 'granularity' distance relative to the leftmost +task so that we do not over-schedule tasks and trash the cache) then the +new leftmost task is picked and the current task is preempted. + +The rq->fair_clock value tracks the 'CPU time a runnable task would have +fairly gotten, had it been runnable during that time'. So by using +rq->fair_clock values we can accurately timestamp and measure the +'expected CPU time' a task should have gotten. All runnable tasks are +sorted in the rbtree by the "rq->fair_clock - p->wait_runtime" key, and +CFS picks the 'leftmost' task and sticks to it. As the system progresses +forwards, newly woken tasks are put into the tree more and more to the +right - slowly but surely giving a chance for every task to become the +'leftmost task' and thus get on the CPU within a deterministic amount of +time. + +Some implementation details: + + - the introduction of Scheduling Classes: an extensible hierarchy of + scheduler modules. These modules encapsulate scheduling policy + details and are handled by the scheduler core without the core + code assuming about them too much. + + - sched_fair.c implements the 'CFS desktop scheduler': it is a + replacement for the vanilla scheduler's SCHED_OTHER interactivity + code. + + I'd like to give credit to Con Kolivas for the general approach here: + he has proven via RSDL/SD that 'fair scheduling' is possible and that + it results in better desktop scheduling. Kudos Con! + + The CFS patch uses a completely different approach and implementation + from RSDL/SD. My goal was to make CFS's interactivity quality exceed + that of RSDL/SD, which is a high standard to meet :-) Testing + feedback is welcome to decide this one way or another. [ and, in any + case, all of SD's logic could be added via a kernel/sched_sd.c module + as well, if Con is interested in such an approach. ] + + CFS's design is quite radical: it does not use runqueues, it uses a + time-ordered rbtree to build a 'timeline' of future task execution, + and thus has no 'array switch' artifacts (by which both the vanilla + scheduler and RSDL/SD are affected). + + CFS uses nanosecond granularity accounting and does not rely on any + jiffies or other HZ detail. Thus the CFS scheduler has no notion of + 'timeslices' and has no heuristics whatsoever. There is only one + central tunable: + + /proc/sys/kernel/sched_granularity_ns + + which can be used to tune the scheduler from 'desktop' (low + latencies) to 'server' (good batching) workloads. It defaults to a + setting suitable for desktop workloads. SCHED_BATCH is handled by the + CFS scheduler module too. + + Due to its design, the CFS scheduler is not prone to any of the + 'attacks' that exist today against the heuristics of the stock + scheduler: fiftyp.c, thud.c, chew.c, ring-test.c, massive_intr.c all + work fine and do not impact interactivity and produce the expected + behavior. + + the CFS scheduler has a much stronger handling of nice levels and + SCHED_BATCH: both types of workloads should be isolated much more + agressively than under the vanilla scheduler. + + ( another detail: due to nanosec accounting and timeline sorting, + sched_yield() support is very simple under CFS, and in fact under + CFS sched_yield() behaves much better than under any other + scheduler i have tested so far. ) + + - sched_rt.c implements SCHED_FIFO and SCHED_RR semantics, in a simpler + way than the vanilla scheduler does. It uses 100 runqueues (for all + 100 RT priority levels, instead of 140 in the vanilla scheduler) + and it needs no expired array. + + - reworked/sanitized SMP load-balancing: the runqueue-walking + assumptions are gone from the load-balancing code now, and + iterators of the scheduling modules are used. The balancing code got + quite a bit simpler as a result. + |
