diff options
Diffstat (limited to 'Documentation')
20 files changed, 403 insertions, 205 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 5b5aba404aac..73060819ed99 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -251,8 +251,6 @@ mono.txt - how to execute Mono-based .NET binaries with the help of BINFMT_MISC. moxa-smartio - file with info on installing/using Moxa multiport serial driver. -mtrr.txt - - how to use PPro Memory Type Range Registers to increase performance. mutex-design.txt - info on the generic mutex subsystem. namespaces/ diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index d8b63d164e41..b8e86460046e 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -337,7 +337,7 @@ With scatterlists, you use the resulting mapping like this: int i, count = dma_map_sg(dev, sglist, nents, direction); struct scatterlist *sg; - for (i = 0, sg = sglist; i < count; i++, sg++) { + for_each_sg(sglist, sg, count, i) { hw_address[i] = sg_dma_address(sg); hw_len[i] = sg_dma_len(sg); } diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index b7b1482f6e04..9d0058e788e5 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -283,6 +283,7 @@ X!Earch/x86/kernel/mca_32.c <chapter id="security"> <title>Security Framework</title> !Isecurity/security.c +!Esecurity/inode.c </chapter> <chapter id="audit"> @@ -364,6 +365,10 @@ X!Edrivers/pnp/system.c !Eblock/blk-barrier.c !Eblock/blk-tag.c !Iblock/blk-tag.c +!Eblock/blk-integrity.c +!Iblock/blktrace.c +!Iblock/genhd.c +!Eblock/genhd.c </chapter> <chapter id="chrdev"> diff --git a/Documentation/SELinux.txt b/Documentation/SELinux.txt new file mode 100644 index 000000000000..07eae00f3314 --- /dev/null +++ b/Documentation/SELinux.txt @@ -0,0 +1,27 @@ +If you want to use SELinux, chances are you will want +to use the distro-provided policies, or install the +latest reference policy release from + http://oss.tresys.com/projects/refpolicy + +However, if you want to install a dummy policy for +testing, you can do using 'mdp' provided under +scripts/selinux. Note that this requires the selinux +userspace to be installed - in particular you will +need checkpolicy to compile a kernel, and setfiles and +fixfiles to label the filesystem. + + 1. Compile the kernel with selinux enabled. + 2. Type 'make' to compile mdp. + 3. Make sure that you are not running with + SELinux enabled and a real policy. If + you are, reboot with selinux disabled + before continuing. + 4. Run install_policy.sh: + cd scripts/selinux + sh install_policy.sh + +Step 4 will create a new dummy policy valid for your +kernel, with a single selinux user, role, and type. +It will compile the policy, will set your SELINUXTYPE to +dummy in /etc/selinux/config, install the compiled policy +as 'dummy', and relabel your filesystem. diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt index c23cab13c3d1..72576769e0f4 100644 --- a/Documentation/block/deadline-iosched.txt +++ b/Documentation/block/deadline-iosched.txt @@ -30,12 +30,18 @@ write_expire (in ms) Similar to read_expire mentioned above, but for writes. -fifo_batch +fifo_batch (number of requests) ---------- -When a read request expires its deadline, we must move some requests from -the sorted io scheduler list to the block device dispatch queue. fifo_batch -controls how many requests we move. +Requests are grouped into ``batches'' of a particular data direction (read or +write) which are serviced in increasing sector order. To limit extra seeking, +deadline expiries are only checked between batches. fifo_batch controls the +maximum number of requests per batch. + +This parameter tunes the balance between per-request latency and aggregate +throughput. When low latency is the primary concern, smaller is better (where +a value of 1 yields first-come first-served behaviour). Increasing fifo_batch +generally improves throughput, at the cost of latency variation. writes_starved (number of dispatches) diff --git a/Documentation/cdrom/ide-cd b/Documentation/cdrom/ide-cd index 91c0dcc6fa5c..2c558cd6c1ef 100644 --- a/Documentation/cdrom/ide-cd +++ b/Documentation/cdrom/ide-cd @@ -145,8 +145,7 @@ useful for reading photocds. To play an audio CD, you should first unmount and remove any data CDROM. Any of the CDROM player programs should then work (workman, -workbone, cdplayer, etc.). Lacking anything else, you could use the -cdtester program in Documentation/cdrom/sbpcd. +workbone, cdplayer, etc.). On a few drives, you can read digital audio directly using a program such as cdda2wav. The only types of drive which I've heard support diff --git a/Documentation/cpu-freq/index.txt b/Documentation/cpu-freq/index.txt index ffdb5323df37..3d0b915035b9 100644 --- a/Documentation/cpu-freq/index.txt +++ b/Documentation/cpu-freq/index.txt @@ -35,11 +35,9 @@ Mailing List ------------ There is a CPU frequency changing CVS commit and general list where you can report bugs, problems or submit patches. To post a message, -send an email to cpufreq@lists.linux.org.uk, to subscribe go to -http://lists.linux.org.uk/mailman/listinfo/cpufreq. Previous post to the -mailing list are available to subscribers at -http://lists.linux.org.uk/mailman/private/cpufreq/. - +send an email to cpufreq@vger.kernel.org, to subscribe go to +http://vger.kernel.org/vger-lists.html#cpufreq and follow the +instructions there. Links ----- @@ -50,7 +48,7 @@ how to access the CVS repository: * http://cvs.arm.linux.org.uk/ the CPUFreq Mailing list: -* http://lists.linux.org.uk/mailman/listinfo/cpufreq +* http://vger.kernel.org/vger-lists.html#cpufreq Clock and voltage scaling for the SA-1100: * http://www.lartmaker.nl/projects/scaling diff --git a/Documentation/hwmon/adt7473 b/Documentation/hwmon/adt7473 index 2126de34c711..1cbf671822e2 100644 --- a/Documentation/hwmon/adt7473 +++ b/Documentation/hwmon/adt7473 @@ -14,14 +14,14 @@ Description This driver implements support for the Analog Devices ADT7473 chip family. -The LM85 uses the 2-wire interface compatible with the SMBUS 2.0 +The ADT7473 uses the 2-wire interface compatible with the SMBUS 2.0 specification. Using an analog to digital converter it measures three (3) -temperatures and two (2) voltages. It has three (3) 16-bit counters for +temperatures and two (2) voltages. It has four (4) 16-bit counters for measuring fan speed. There are three (3) PWM outputs that can be used to control fan speed. A sophisticated control system for the PWM outputs is designed into the -LM85 that allows fan speed to be adjusted automatically based on any of the +ADT7473 that allows fan speed to be adjusted automatically based on any of the three temperature sensors. Each PWM output is individually adjustable and programmable. Once configured, the ADT7473 will adjust the PWM outputs in response to the measured temperatures without further host intervention. @@ -46,14 +46,6 @@ from the raw value to get the temperature value. The Analog Devices datasheet is very detailed and describes a procedure for determining an optimal configuration for the automatic PWM control. -Hardware Configurations ------------------------ - -The ADT7473 chips have an optional SMBALERT output that can be used to -signal the chipset in case a limit is exceeded or the temperature sensors -fail. Individual sensor interrupts can be masked so they won't trigger -SMBALERT. The SMBALERT output if configured replaces the PWM2 function. - Configuration Notes ------------------- @@ -61,8 +53,8 @@ Besides standard interfaces driver adds the following: * PWM Control -* pwm#_auto_point1_pwm and pwm#_auto_point1_temp and -* pwm#_auto_point2_pwm and pwm#_auto_point2_temp - +* pwm#_auto_point1_pwm and temp#_auto_point1_temp and +* pwm#_auto_point2_pwm and temp#_auto_point2_temp - point1: Set the pwm speed at a lower temperature bound. point2: Set the pwm speed at a higher temperature bound. diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface index 2d845730d4e0..6dbfd5efd991 100644 --- a/Documentation/hwmon/sysfs-interface +++ b/Documentation/hwmon/sysfs-interface @@ -329,6 +329,10 @@ power[1-*]_average Average power use Unit: microWatt RO +power[1-*]_average_interval Power use averaging interval + Unit: milliseconds + RW + power[1-*]_average_highest Historical average maximum power use Unit: microWatt RO @@ -354,6 +358,14 @@ power[1-*]_reset_history Reset input_highest, input_lowest, WO ********** +* Energy * +********** + +energy[1-*]_input Cumulative energy use + Unit: microJoule + RO + +********** * Alarms * ********** diff --git a/Documentation/kernel-doc-nano-HOWTO.txt b/Documentation/kernel-doc-nano-HOWTO.txt index 0bd32748a467..c6841eee9598 100644 --- a/Documentation/kernel-doc-nano-HOWTO.txt +++ b/Documentation/kernel-doc-nano-HOWTO.txt @@ -168,10 +168,10 @@ if ($#ARGV < 0) { mkdir $ARGV[0],0777; $state = 0; while (<STDIN>) { - if (/^\.TH \"[^\"]*\" 4 \"([^\"]*)\"/) { + if (/^\.TH \"[^\"]*\" 9 \"([^\"]*)\"/) { if ($state == 1) { close OUT } $state = 1; - $fn = "$ARGV[0]/$1.4"; + $fn = "$ARGV[0]/$1.9"; print STDERR "Creating $fn\n"; open OUT, ">$fn" or die "can't open $fn: $!\n"; print OUT $_; diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 1150444a21ab..329dcabe4c5e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -463,12 +463,6 @@ and is between 256 and 4096 characters. It is defined in the file Range: 0 - 8192 Default: 64 - disable_8254_timer - enable_8254_timer - [IA32/X86_64] Disable/Enable interrupt 0 timer routing - over the 8254 in addition to over the IO-APIC. The - kernel tries to set a sensible default. - hpet= [X86-32,HPET] option to control HPET usage Format: { enable (default) | disable | force } disable: disable HPET and use PIT instead @@ -1882,6 +1876,12 @@ and is between 256 and 4096 characters. It is defined in the file shapers= [NET] Maximal number of shapers. + show_msr= [x86] show boot-time MSR settings + Format: { <integer> } + Show boot-time (BIOS-initialized) MSR settings. + The parameter means the number of CPUs to show, + for example 1 means boot CPU only. + sim710= [SCSI,HW] See header of drivers/scsi/sim710.c. diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt index 88bcb8767335..9d8eb553884c 100644 --- a/Documentation/scheduler/sched-design-CFS.txt +++ b/Documentation/scheduler/sched-design-CFS.txt @@ -1,151 +1,242 @@ + ============= + CFS Scheduler + ============= -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 (you have to switch on CONFIG_SCHED_DEBUG): - - /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. - - -Group scheduler extension to CFS -================================ - -Normally the scheduler operates on individual tasks and strives to provide -fair CPU time to each task. Sometimes, it may be desirable to group tasks -and provide fair CPU time to each such task group. For example, it may -be desirable to first provide fair CPU time to each user on the system -and then to each task belonging to a user. - -CONFIG_FAIR_GROUP_SCHED strives to achieve exactly that. It lets -SCHED_NORMAL/BATCH tasks be be grouped and divides CPU time fairly among such -groups. At present, there are two (mutually exclusive) mechanisms to group -tasks for CPU bandwidth control purpose: - - - Based on user id (CONFIG_FAIR_USER_SCHED) - In this option, tasks are grouped according to their user id. - - Based on "cgroup" pseudo filesystem (CONFIG_FAIR_CGROUP_SCHED) - This options lets the administrator create arbitrary groups - of tasks, using the "cgroup" pseudo filesystem. See - Documentation/cgroups.txt for more information about this - filesystem. -Only one of these options to group tasks can be chosen and not both. +1. OVERVIEW + +CFS stands for "Completely Fair Scheduler," and is the new "desktop" process +scheduler implemented by Ingo Molnar and merged in Linux 2.6.23. It is the +replacement for the previous vanilla scheduler's SCHED_OTHER interactivity +code. + +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 --- i.e., actually in parallel. + +On real hardware, we can run only a single task at once, so we have to +introduce the concept of "virtual runtime." The virtual runtime of a task +specifies when its next timeslice would start execution on the ideal +multi-tasking CPU described above. In practice, the virtual runtime of a task +is its actual runtime normalized to the total number of running tasks. + + + +2. FEW IMPLEMENTATION DETAILS + +In CFS the virtual runtime is expressed and tracked via the per-task +p->se.vruntime (nanosec-unit) value. This way, it's possible to accurately +timestamp and measure the "expected CPU time" a task should have gotten. + +[ small detail: on "ideal" hardware, at any time all tasks would have the same + p->se.vruntime value --- i.e., tasks would execute simultaneously and 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->se.vruntime value and it is thus +very simple: it always tries to run the task with the smallest p->se.vruntime +value (i.e., the task which executed least so far). 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. + + + +3. THE RBTREE + +CFS's design is quite radical: it does not use the old data structures for the +runqueues, but 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 +previous vanilla scheduler and RSDL/SD are affected). + +CFS also maintains the rq->cfs.min_vruntime value, which is a monotonic +increasing value tracking the smallest vruntime among all tasks in the +runqueue. The total amount of work done by the system is tracked using +min_vruntime; that value is used to place newly activated entities on the left +side of the tree as much as possible. + +The total number of running tasks in the runqueue is accounted through the +rq->cfs.load value, which is the sum of the weights of the tasks queued on the +runqueue. + +CFS maintains a time-ordered rbtree, where all runnable tasks are sorted by the +p->se.vruntime key (there is a subtraction using rq->cfs.min_vruntime to +account for possible wraparounds). CFS picks the "leftmost" task from this +tree and sticks to it. +As the system progresses forwards, the executed 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. + +Summing up, CFS works like this: it 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 added to +p->se.vruntime. Once p->se.vruntime gets high 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. + + + +4. SOME FEATURES OF CFS + +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" in the +way the previous scheduler had, and has no heuristics whatsoever. There is +only one central tunable (you have to switch on CONFIG_SCHED_DEBUG): + + /proc/sys/kernel/sched_granularity_ns + +which can be used to tune the scheduler from "desktop" (i.e., low latencies) to +"server" (i.e., 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 +than the previous vanilla scheduler: both types of workloads are isolated much +more aggressively. + +SMP load-balancing has been reworked/sanitized: 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. + + + +5. Scheduling policies + +CFS implements three scheduling policies: + + - SCHED_NORMAL (traditionally called SCHED_OTHER): The scheduling + policy that is used for regular tasks. + + - SCHED_BATCH: Does not preempt nearly as often as regular tasks + would, thereby allowing tasks to run longer and make better use of + caches but at the cost of interactivity. This is well suited for + batch jobs. + + - SCHED_IDLE: This is even weaker than nice 19, but its not a true + idle timer scheduler in order to avoid to get into priority + inversion problems which would deadlock the machine. + +SCHED_FIFO/_RR are implemented in sched_rt.c and are as specified by +POSIX. + +The command chrt from util-linux-ng 2.13.1.1 can set all of these except +SCHED_IDLE. -Group scheduler tunables: -When CONFIG_FAIR_USER_SCHED is defined, a directory is created in sysfs for -each new user and a "cpu_share" file is added in that directory. + +6. SCHEDULING CLASSES + +The new CFS scheduler has been designed in such a way to introduce "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 too much about them. + +sched_fair.c implements the CFS scheduler described above. + +sched_rt.c implements SCHED_FIFO and SCHED_RR semantics, in a simpler way than +the previous vanilla scheduler did. It uses 100 runqueues (for all 100 RT +priority levels, instead of 140 in the previous scheduler) and it needs no +expired array. + +Scheduling classes are implemented through the sched_class structure, which +contains hooks to functions that must be called whenever an interesting event +occurs. + +This is the (partial) list of the hooks: + + - enqueue_task(...) + + Called when a task enters a runnable state. + It puts the scheduling entity (task) into the red-black tree and + increments the nr_running variable. + + - dequeue_tree(...) + + When a task is no longer runnable, this function is called to keep the + corresponding scheduling entity out of the red-black tree. It decrements + the nr_running variable. + + - yield_task(...) + + This function is basically just a dequeue followed by an enqueue, unless the + compat_yield sysctl is turned on; in that case, it places the scheduling + entity at the right-most end of the red-black tree. + + - check_preempt_curr(...) + + This function checks if a task that entered the runnable state should + preempt the currently running task. + + - pick_next_task(...) + + This function chooses the most appropriate task eligible to run next. + + - set_curr_task(...) + + This function is called when a task changes its scheduling class or changes + its task group. + + - task_tick(...) + + This function is mostly called from time tick functions; it might lead to + process switch. This drives the running preemption. + + - task_new(...) + + The core scheduler gives the scheduling module an opportunity to manage new + task startup. The CFS scheduling module uses it for group scheduling, while + the scheduling module for a real-time task does not use it. + + + +7. GROUP SCHEDULER EXTENSIONS TO CFS + +Normally, the scheduler operates on individual tasks and strives to provide +fair CPU time to each task. Sometimes, it may be desirable to group tasks and +provide fair CPU time to each such task group. For example, it may be +desirable to first provide fair CPU time to each user on the system and then to +each task belonging to a user. + +CONFIG_GROUP_SCHED strives to achieve exactly that. It lets tasks to be +grouped and divides CPU time fairly among such groups. + +CONFIG_RT_GROUP_SCHED permits to group real-time (i.e., SCHED_FIFO and +SCHED_RR) tasks. + +CONFIG_FAIR_GROUP_SCHED permits to group CFS (i.e., SCHED_NORMAL and +SCHED_BATCH) tasks. + +At present, there are two (mutually exclusive) mechanisms to group tasks for +CPU bandwidth control purposes: + + - Based on user id (CONFIG_USER_SCHED) + + With this option, tasks are grouped according to their user id. + + - Based on "cgroup" pseudo filesystem (CONFIG_CGROUP_SCHED) + + This options needs CONFIG_CGROUPS to be defined, and lets the administrator + create arbitrary groups of tasks, using the "cgroup" pseudo filesystem. See + Documentation/cgroups.txt for more information about this filesystem. + +Only one of these options to group tasks can be chosen and not both. + +When CONFIG_USER_SCHED is defined, a directory is created in sysfs for each new +user and a "cpu_share" file is added in that directory. # cd /sys/kernel/uids # cat 512/cpu_share # Display user 512's CPU share @@ -155,16 +246,14 @@ each new user and a "cpu_share" file is added in that directory. 2048 # -CPU bandwidth between two users are divided in the ratio of their CPU shares. -For ex: if you would like user "root" to get twice the bandwidth of user -"guest", then set the cpu_share for both the users such that "root"'s -cpu_share is twice "guest"'s cpu_share - +CPU bandwidth between two users is divided in the ratio of their CPU shares. +For example: if you would like user "root" to get twice the bandwidth of user +"guest," then set the cpu_share for both the users such that "root"'s cpu_share +is twice "guest"'s cpu_share. -When CONFIG_FAIR_CGROUP_SCHED is defined, a "cpu.shares" file is created -for each group created using the pseudo filesystem. See example steps -below to create task groups and modify their CPU share using the "cgroups" -pseudo filesystem +When CONFIG_CGROUP_SCHED is defined, a "cpu.shares" file is created for each +group created using the pseudo filesystem. See example steps below to create +task groups and modify their CPU share using the "cgroups" pseudo filesystem. # mkdir /dev/cpuctl # mount -t cgroup -ocpu none /dev/cpuctl diff --git a/Documentation/scsi/scsi_fc_transport.txt b/Documentation/scsi/scsi_fc_transport.txt index 75143f0c23b6..38d324d62b25 100644 --- a/Documentation/scsi/scsi_fc_transport.txt +++ b/Documentation/scsi/scsi_fc_transport.txt @@ -436,6 +436,42 @@ Other: was updated to remove all vports for the fc_host as well. +Transport supplied functions +---------------------------- + +The following functions are supplied by the FC-transport for use by LLDs. + + fc_vport_create - create a vport + fc_vport_terminate - detach and remove a vport + +Details: + +/** + * fc_vport_create - Admin App or LLDD requests creation of a vport + * @shost: scsi host the virtual port is connected to. + * @ids: The world wide names, FC4 port roles, etc for + * the virtual port. + * + * Notes: + * This routine assumes no locks are held on entry. + */ +struct fc_vport * +fc_vport_create(struct Scsi_Host *shost, struct fc_vport_identifiers *ids) + +/** + * fc_vport_terminate - Admin App or LLDD requests termination of a vport + * @vport: fc_vport to be terminated + * + * Calls the LLDD vport_delete() function, then deallocates and removes + * the vport from the shost and object tree. + * + * Notes: + * This routine assumes no locks are held on entry. + */ +int +fc_vport_terminate(struct fc_vport *vport) + + Credits ======= The following people have contributed to this document: diff --git a/Documentation/x86/00-INDEX b/Documentation/x86/00-INDEX new file mode 100644 index 000000000000..dbe3377754af --- /dev/null +++ b/Documentation/x86/00-INDEX @@ -0,0 +1,4 @@ +00-INDEX + - this file +mtrr.txt + - how to use x86 Memory Type Range Registers to increase performance diff --git a/Documentation/x86/i386/boot.txt b/Documentation/x86/boot.txt index 147bfe511cdd..83c0033ee9e0 100644 --- a/Documentation/x86/i386/boot.txt +++ b/Documentation/x86/boot.txt @@ -308,7 +308,7 @@ Protocol: 2.00+ Field name: start_sys Type: read -Offset/size: 0x20c/4 +Offset/size: 0x20c/2 Protocol: 2.00+ The load low segment (0x1000). Obsolete. diff --git a/Documentation/mtrr.txt b/Documentation/x86/mtrr.txt index c39ac395970e..cc071dc333c2 100644 --- a/Documentation/mtrr.txt +++ b/Documentation/x86/mtrr.txt @@ -18,7 +18,7 @@ Richard Gooch The AMD K6-2 (stepping 8 and above) and K6-3 processors have two MTRRs. These are supported. The AMD Athlon family provide 8 Intel style MTRRs. - + The Centaur C6 (WinChip) has 8 MCRs, allowing write-combining. These are supported. @@ -87,7 +87,7 @@ reg00: base=0x00000000 ( 0MB), size= 64MB: write-back, count=1 reg01: base=0xfb000000 (4016MB), size= 16MB: write-combining, count=1 reg02: base=0xfb000000 (4016MB), size= 4kB: uncachable, count=1 -Some cards (especially Voodoo Graphics boards) need this 4 kB area +Some cards (especially Voodoo Graphics boards) need this 4 kB area excluded from the beginning of the region because it is used for registers. diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt index 17965f927c15..c93ff5f4c0dd 100644 --- a/Documentation/x86/pat.txt +++ b/Documentation/x86/pat.txt @@ -14,6 +14,10 @@ PAT allows for different types of memory attributes. The most commonly used ones that will be supported at this time are Write-back, Uncached, Write-combined and Uncached Minus. + +PAT APIs +-------- + There are many different APIs in the kernel that allows setting of memory attributes at the page level. In order to avoid aliasing, these interfaces should be used thoughtfully. Below is a table of interfaces available, @@ -26,38 +30,38 @@ address range to avoid any aliasing. API | RAM | ACPI,... | Reserved/Holes | -----------------------|----------|------------|------------------| | | | | -ioremap | -- | UC | UC | +ioremap | -- | UC- | UC- | | | | | ioremap_cache | -- | WB | WB | | | | | -ioremap_nocache | -- | UC | UC | +ioremap_nocache | -- | UC- | UC- | | | | | ioremap_wc | -- | -- | WC | | | | | -set_memory_uc | UC | -- | -- | +set_memory_uc | UC- | -- | -- | set_memory_wb | | | | | | | | set_memory_wc | WC | -- | -- | set_memory_wb | | | | | | | | -pci sysfs resource | -- | -- | UC | +pci sysfs resource | -- | -- | UC- | | | | | pci sysfs resource_wc | -- | -- | WC | is IORESOURCE_PREFETCH| | | | | | | | -pci proc | -- | -- | UC | +pci proc | -- | -- | UC- | !PCIIOC_WRITE_COMBINE | | | | | | | | pci proc | -- | -- | WC | PCIIOC_WRITE_COMBINE | | | | | | | | -/dev/mem | -- | UC | UC | +/dev/mem | -- | WB/WC/UC- | WB/WC/UC- | read-write | | | | | | | | -/dev/mem | -- | UC | UC | +/dev/mem | -- | UC- | UC- | mmap SYNC flag | | | | | | | | -/dev/mem | -- | WB/WC/UC | WB/WC/UC | +/dev/mem | -- | WB/WC/UC- | WB/WC/UC- | mmap !SYNC flag | |(from exist-| (from exist- | and | | ing alias)| ing alias) | any alias to this area| | | | @@ -68,7 +72,7 @@ pci proc | -- | -- | WC | and | | | | MTRR says WB | | | | | | | | -/dev/mem | -- | -- | UC_MINUS | +/dev/mem | -- | -- | UC- | mmap !SYNC flag | | | | no alias to this area | | | | and | | | | @@ -98,3 +102,35 @@ types. Drivers should use set_memory_[uc|wc] to set access type for RAM ranges. + +PAT debugging +------------- + +With CONFIG_DEBUG_FS enabled, PAT memtype list can be examined by + +# mount -t debugfs debugfs /sys/kernel/debug +# cat /sys/kernel/debug/x86/pat_memtype_list +PAT memtype list: +uncached-minus @ 0x7fadf000-0x7fae0000 +uncached-minus @ 0x7fb19000-0x7fb1a000 +uncached-minus @ 0x7fb1a000-0x7fb1b000 +uncached-minus @ 0x7fb1b000-0x7fb1c000 +uncached-minus @ 0x7fb1c000-0x7fb1d000 +uncached-minus @ 0x7fb1d000-0x7fb1e000 +uncached-minus @ 0x7fb1e000-0x7fb25000 +uncached-minus @ 0x7fb25000-0x7fb26000 +uncached-minus @ 0x7fb26000-0x7fb27000 +uncached-minus @ 0x7fb27000-0x7fb28000 +uncached-minus @ 0x7fb28000-0x7fb2e000 +uncached-minus @ 0x7fb2e000-0x7fb2f000 +uncached-minus @ 0x7fb2f000-0x7fb30000 +uncached-minus @ 0x7fb31000-0x7fb32000 +uncached-minus @ 0x80000000-0x90000000 + +This list shows physical address ranges and various PAT settings used to +access those physical address ranges. + +Another, more verbose way of getting PAT related debug messages is with +"debugpat" boot parameter. With this parameter, various debug messages are +printed to dmesg log. + diff --git a/Documentation/x86/i386/usb-legacy-support.txt b/Documentation/x86/usb-legacy-support.txt index 1894cdfc69d9..1894cdfc69d9 100644 --- a/Documentation/x86/i386/usb-legacy-support.txt +++ b/Documentation/x86/usb-legacy-support.txt diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index b0c7b6c4abda..72ffb5373ec7 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -54,10 +54,6 @@ APICs apicmaintimer. Useful when your PIT timer is totally broken. - disable_8254_timer / enable_8254_timer - Enable interrupt 0 timer routing over the 8254 in addition to over - the IO-APIC. The kernel tries to set a sensible default. - Early Console syntax: earlyprintk=vga diff --git a/Documentation/x86/i386/zero-page.txt b/Documentation/x86/zero-page.txt index 169ad423a3d1..169ad423a3d1 100644 --- a/Documentation/x86/i386/zero-page.txt +++ b/Documentation/x86/zero-page.txt |