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* Task Control Groups: example CPU accounting subsystemPaul Menage2007-10-19
| | | | | | | | | | | | | | | | | | | | | This example demonstrates how to use the generic cgroup subsystem for a simple resource tracker that counts, for the processes in a cgroup, the total CPU time used and the %CPU used in the last complete 10 second interval. Portions contributed by Balbir Singh <balbir@in.ibm.com> Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-schedLinus Torvalds2007-10-18
|\ | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched: sched: reduce schedstat variable overhead a bit sched: add KERN_CONT annotation sched: cleanup, make struct rq comments more consistent sched: cleanup, fix spacing sched: fix return value of wait_for_completion_interruptible()
| * sched: reduce schedstat variable overhead a bitKen Chen2007-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | schedstat is useful in investigating CPU scheduler behavior. Ideally, I think it is beneficial to have it on all the time. However, the cost of turning it on in production system is quite high, largely due to number of events it collects and also due to its large memory footprint. Most of the fields probably don't need to be full 64-bit on 64-bit arch. Rolling over 4 billion events will most like take a long time and user space tool can be made to accommodate that. I'm proposing kernel to cut back most of variable width on 64-bit system. (note, the following patch doesn't affect 32-bit system). Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: add KERN_CONT annotationIngo Molnar2007-10-18
| | | | | | | | | | | | | | printk: add the KERN_CONT annotation (which is empty string but via which checkpatch.pl can notice that the lacking KERN_ level is fine). Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: cleanup, make struct rq comments more consistentIngo Molnar2007-10-18
| | | | | | | | | | | | | | | | cleanup, make struct rq comments more consistent. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: cleanup, fix spacingIngo Molnar2007-10-18
| | | | | | | | | | | | | | | | | | cleanup: fix sysctl_sched_features initialization spacing, and fix sd_alloc_ctl_cpu_table() prototype spacing. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: fix return value of wait_for_completion_interruptible()Andi Kleen2007-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent wait_for_completion() cleanups: commit 8cbbe86dfcfd68ad69916164bdc838d9e09adca8 Author: Andi Kleen <ak@suse.de> Date: Mon Oct 15 17:00:14 2007 +0200 sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion broke the return value of wait_for_completion_interruptible(). Previously it returned 0 on success, now -1. Fix that. Problem found by Geert Uytterhoeven. [ mingo: fixed whitespace damage ] Reported-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Add scaled time to taskstats based process accountingMichael Neuling2007-10-18
|/ | | | | | | | | | | | | | | | This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-schedLinus Torvalds2007-10-17
|\ | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched: sched: fix new task startup crash sched: fix !SYSFS build breakage sched: fix improper load balance across sched domain sched: more robust sd-sysctl entry freeing
| * sched: fix new task startup crashSrivatsa Vaddagiri2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Child task may be added on a different cpu that the one on which parent is running. In which case, task_new_fair() should check whether the new born task's parent entity should be added as well on the cfs_rq. Patch below fixes the problem in task_new_fair. This could fix the put_prev_task_fair() crashes reported. Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Reported-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: fix improper load balance across sched domainKen Chen2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We recently discovered a nasty performance bug in the kernel CPU load balancer where we were hit by 50% performance regression. When tasks are assigned to a subset of CPUs that span across sched_domains (either ccNUMA node or the new multi-core domain) via cpu affinity, kernel fails to perform proper load balance at these domains, due to several logic in find_busiest_group() miss identified busiest sched group within a given domain. This leads to inadequate load balance and causes 50% performance hit. To give you a concrete example, on a dual-core, 2 socket numa system, there are 4 logical cpu, organized as: CPU0 attaching sched-domain: domain 0: span 0003 groups: 0001 0002 domain 1: span 000f groups: 0003 000c CPU1 attaching sched-domain: domain 0: span 0003 groups: 0002 0001 domain 1: span 000f groups: 0003 000c CPU2 attaching sched-domain: domain 0: span 000c groups: 0004 0008 domain 1: span 000f groups: 000c 0003 CPU3 attaching sched-domain: domain 0: span 000c groups: 0008 0004 domain 1: span 000f groups: 000c 0003 If I run 2 tasks with CPU affinity set to 0x5. There are situation where cpu0 has run queue length of 2, and cpu2 will be idle. The kernel load balancer is unable to balance out these two tasks over cpu0 and cpu2 due to at least three logics in find_busiest_group() that heavily bias load balance towards power saving mode. e.g. while determining "busiest" variable, kernel only set it when "sum_nr_running > group_capacity". This test is flawed that "sum_nr_running" is not necessary same as sum-tasks-allowed-to-run-within-the sched-group. The end result is that kernel "think" everything is balanced, but in reality we have an imbalance and thus causing one CPU to be over-subscribed and leaving other idle. There are two other logic in the same function will also causing similar effect. The nastiness of this bug is that kernel not be able to get unstuck in this unfortunate broken state. From what we've seen in our environment, kernel will stuck in imbalanced state for extended period of time and it is also very easy for the kernel to stuck into that state (it's pretty much 100% reproducible for us). So proposing the following fix: add addition logic in find_busiest_group to detect intrinsic imbalance within the busiest group. When such condition is detected, load balance goes into spread mode instead of default grouping mode. Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: more robust sd-sysctl entry freeingMilton Miller2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It occurred to me this morning that the procname field was dynamically allocated and needed to be freed. I started to put in break statements when allocation failed but it was approaching 50% error handling code. I came up with this alternative of looping while entry->mode is set and checking proc_handler instead of ->table. Alternatively, the string version of the domain name and cpu number could be stored the structs. I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation counts after taking a cpuset exclusive and back. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | migration_call(CPU_DEAD): use spin_lock_irq() instead of task_rq_lock()Oleg Nesterov2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change migration_call(CPU_DEAD) to use direct spin_lock_irq() instead of task_rq_lock(rq->idle), rq->idle can't change its task_rq(). This makes the code a bit more symmetrical with migrate_dead_tasks()'s path which uses spin_lock_irq/spin_unlock_irq. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | do CPU_DEAD migrating under read_lock(tasklist) instead of ↵Oleg Nesterov2007-10-17
|/ | | | | | | | | | | | | | | | | | | | | | | write_lock_irq(tasklist) Currently move_task_off_dead_cpu() is called under write_lock_irq(tasklist). This means it can't use task_lock() which is needed to improve migrating to take task's ->cpuset into account. Change the code to call move_task_off_dead_cpu() with irqs enabled, and change migrate_live_tasks() to use read_lock(tasklist). This all is a preparation for the futher changes proposed by Cliff Wickman, see http://marc.info/?t=117327786100003 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuset: remove sched domain hooks from cpusetsPaul Jackson2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the cpuset hooks that defined sched domains depending on the setting of the 'cpu_exclusive' flag. The cpu_exclusive flag can only be set on a child if it is set on the parent. This made that flag painfully unsuitable for use as a flag defining a partitioning of a system. It was entirely unobvious to a cpuset user what partitioning of sched domains they would be causing when they set that one cpu_exclusive bit on one cpuset, because it depended on what CPUs were in the remainder of that cpusets siblings and child cpusets, after subtracting out other cpu_exclusive cpusets. Furthermore, there was no way on production systems to query the result. Using the cpu_exclusive flag for this was simply wrong from the get go. Fortunately, it was sufficiently borked that so far as I know, almost no successful use has been made of this. One real time group did use it to affectively isolate CPUs from any load balancing efforts. They are willing to adapt to alternative mechanisms for this, such as someway to manipulate the list of isolated CPUs on a running system. They can do without this present cpu_exclusive based mechanism while we develop an alternative. There is a real risk, to the best of my understanding, of users accidentally setting up a partitioned scheduler domains, inhibiting desired load balancing across all their CPUs, due to the nonobvious (from the cpuset perspective) side affects of the cpu_exclusive flag. Furthermore, since there was no way on a running system to see what one was doing with sched domains, this change will be invisible to any using code. Unless they have real insight to the scheduler load balancing choices, they will be unable to detect that this change has been made in the kernel's behaviour. Initial discussion on lkml of this patch has generated much comment. My (probably controversial) take on that discussion is that it has reached a rough concensus that the current cpuset cpu_exclusive mechanism for defining sched domains is borked. There is no concensus on the replacement. But since we can remove this mechanism, and since its continued presence risks causing unwanted partitioning of the schedulers load balancing, we should remove it while we can, as we proceed to work the replacement scheduler domain mechanisms. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Convert cpu_sibling_map to be a per cpu variableMike Travis2007-10-16
| | | | | | | | | | | | | | | | | Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu variable. This saves sizeof(cpumask_t) * NR unused cpus. Access is mostly from startup and CPU HOTPLUG functions. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: sync wakeups preempt tooIngo Molnar2007-10-15
| | | | | | | | | | make sure sync wakeups preempt too - the scheduler will not overschedule as we've got various throttles against that. As a result, sync wakeups can be used more widely in the kernel (to signal wakeup affinity between tasks), and no arbitrary latencies will be introduced either. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: affine sync wakeupsIngo Molnar2007-10-15
| | | | | | | | make sync wakeups affine for cache-cold tasks: if a cache-cold task is woken up by a sync wakeup then use the opportunity to migrate it straight away. (the two tasks are 'related' because they communicate) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: guest CPU accounting: maintain stats in account_system_time()Laurent Vivier2007-10-15
| | | | | | | | | | | | | | | modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: domain sysctl fixes: add terminator commentMilton Miller2007-10-15
| | | | | | | | we had an incorrect-terminator bug in sd_alloc_ctl_domain_table() before, so add a comment that documents it. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: domain sysctl fixes: do not crash on allocation failureMilton Miller2007-10-15
| | | | | | | | | Now that we are calling this at runtime, a more relaxed error path is suggested. If an allocation fails, we just register the partial table, which will show empty directories. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: domain sysctl fixes: unregister the sysctl table before domainsMilton Miller2007-10-15
| | | | | | | | | Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: domain sysctl fixes: use for_each_online_cpu()Milton Miller2007-10-15
| | | | | | | | | | init_sched_domain_sysctl was walking cpus 0-n and referencing per_cpu variables. If the cpus_possible mask is not contigious this will result in a crash referencing unallocated data. If the online mask is not contigious then we would show offline cpus and miss online ones. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: domain sysctl fixes: use kcalloc()Milton Miller2007-10-15
| | | | | | | kcalloc checks for n * sizeof(element) overflows and it zeros. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: allow the immediate migration of cache-cold tasksIngo Molnar2007-10-15
| | | | | | allow the immediate migration of cache-cold tasks. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: debug, improve migration statisticsIngo Molnar2007-10-15
| | | | | | | add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: activate task_hot() only on fair-scheduled tasksPeter Zijlstra2007-10-15
| | | | | | | | activate task_hot() only for fair-scheduled tasks (i.e. disable it for RT tasks). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: reintroduce cache-hot affinityIngo Molnar2007-10-15
| | | | | | | | reintroduce a simplified version of cache-hot/cold scheduling affinity. This improves performance with certain SMP workloads, such as sysbench. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: do not normalize kernel threads via SysRq-NIngo Molnar2007-10-15
| | | | | | | | | | do not normalize kernel threads via SysRq-N: the migration threads, softlockup threads, etc. might be essential for the system to function properly. So only zap user tasks. pointed out by Andi Kleen. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: remove stale comment from sched_group_set_shares()Andi Kleen2007-10-15
| | | | | | | | | remove stale comment from sched_group_set_shares(). Function never returns -EINVAL. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: clean up is_migration_thread()Ingo Molnar2007-10-15
| | | | | | clean up is_migration_thread() and turn it into an inline function. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: cleanup: refactor normalize_rt_tasksAndi Kleen2007-10-15
| | | | | | | | Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: cleanup: refactor common code of sleep_on / wait_for_completionAndi Kleen2007-10-15
| | | | | | | | | | | | | Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: cleanup: remove unnecessary gotosAndi Kleen2007-10-15
| | | | | | | | | | Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: prevent wakeup over-schedulingMike Galbraith2007-10-15
| | | | | | | | | | | Prevent wakeup over-scheduling. Once a task has been preempted by a task of the same or lower priority, it becomes ineligible for repeated preemption by same until it has been ticked, or slept. Instead, the task is marked for preemption at the next tick. Tasks of higher priority still preempt immediately. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: disable forced preemption by defaultPeter Zijlstra2007-10-15
| | | | | | | | Implement feature bit to disable forced preemption. This way it can be checked whether a workload is overscheduling or not. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: some proc entries are missed in sched_domain sys_ctl debug codeZou Nan hai2007-10-15
| | | | | | | | | | | cache_nice_tries and flags entry do not appear in proc fs sched_domain directory, because ctl_table entry is skipped. This patch fixes the issue. Signed-off-by: Zou Nan hai <nanhai.zou@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: fix rt ptracer monopolizing CPUGautham R Shenoy2007-10-15
| | | | | | | | | | | | | yield() in wait_task_inactive(), can cause a high priority thread to be scheduled back in, and there by loop forever while it is waiting for some lower priority thread which is unfortunately still on the runqueue. Use schedule_timeout_uninterruptible(1) instead. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Credit: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: group scheduling, sysfs tunablesDhaval Giani2007-10-15
| | | | | | | | | | | | | | | | | | | | | | | | | Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: export cpu_clock()Paul E. McKenney2007-10-15
| | | | | | | | export cpu_clock() - the preferred API instead of sched_clock(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: fix: move the CPU check into ->task_new_fair()Ingo Molnar2007-10-15
| | | | | | | | | | | | | noticed by Peter Zijlstra: fix: move the CPU check into ->task_new_fair(), this way we can call place_entity() and get child ->vruntime right at initial wakeup time. (without this there can be large latencies) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* sched: cleanup: rename task_grp to task_groupIngo Molnar2007-10-15
| | | | | | | cleanup: rename task_grp to task_group. No need to save two characters and 'grp' is annoying to read. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVGIngo Molnar2007-10-15
| | | | | | | cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVG, to make SCHED_FEAT_ names more consistent. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: kfree(NULL) is validIngo Molnar2007-10-15
| | | | | | | | | | | | | | kfree(NULL) is valid. pointed out by checkpatch.pl. the fix shrinks the code a bit: text data bss dec hex filename 40024 3842 100 43966 abbe sched.o.before 40002 3842 100 43944 aba8 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: style cleanupIngo Molnar2007-10-15
| | | | | | fix up __setup() style bug - noticed via checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: break out if printing a warning in sched_domain_debug()Ingo Molnar2007-10-15
| | | | | | | checkpatch.pl and Andy Whitcroft noticed the following bug: we did not break out after printing an error. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: run sched_domain_debug() if CONFIG_SCHED_DEBUG=yIngo Molnar2007-10-15
| | | | | | | run sched_domain_debug() if CONFIG_SCHED_DEBUG=y, instead of relying on the hand-crafted SCHED_DOMAIN_DEBUG switch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: tidy up SCHED_RRDmitry Adamushko2007-10-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - make timeslices of SCHED_RR tasks constant and not dependent on task's static_prio [1] ; - remove obsolete code (timeslice related bits); - make sched_rr_get_interval() return something more meaningful [2] for SCHED_OTHER tasks. [1] according to the following link, it's not compliant with SUSv3 (not sure though, what is the reference for us :-) http://lkml.org/lkml/2007/3/7/656 [2] the interval is dynamic and can be depicted as follows "should a task be one of the runnable tasks at this particular moment, it would expect to run for this interval of time before being re-scheduled by the scheduler tick". (i.e. it's more precise if a task is runnable at the moment) yeah, this seems to require task_rq_lock/unlock() but this is not a hot path. results: (SCHED_FIFO) dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval time_slice: 0 : 0 (SCHED_RR) dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval time_slice: 0 : 99984800 (SCHED_NORMAL) dimm@earth:~/storage/prog$ ./rr_interval time_slice: 0 : 19996960 (SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result) dimm@earth:~/storage/prog$ taskset 1 ./rr_interval time_slice: 0 : 9998480 Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: uninline schedulerAlexey Dobriyan2007-10-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * save ~300 bytes * activate_idle_task() was moved to avoid a warning bloat-o-meter output: add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295) <=== function old new delta __enqueue_entity - 165 +165 finish_task_switch - 110 +110 update_curr_rt - 79 +79 __load_balance_iterator - 32 +32 __task_rq_unlock - 28 +28 find_process_by_pid - 24 +24 do_sched_setscheduler 133 123 -10 sys_sched_rr_get_interval 176 165 -11 sys_sched_getparam 156 145 -11 normalize_rt_tasks 482 470 -12 sched_getaffinity 112 99 -13 sys_sched_getscheduler 86 72 -14 sched_setaffinity 226 212 -14 sched_setscheduler 666 642 -24 load_balance_start_fair 33 9 -24 load_balance_next_fair 33 9 -24 dequeue_task_rt 133 67 -66 put_prev_task_rt 97 28 -69 schedule_tail 133 50 -83 schedule 682 594 -88 enqueue_entity 499 366 -133 task_new_fair 317 180 -137 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: optimize schedule() a bit on SMPIngo Molnar2007-10-15
| | | | | | | | | | | | | | optimize schedule() a bit on SMP, by moving the rq-clock update outside the rq lock. code size is the same: text data bss dec hex filename 25725 2666 96 28487 6f47 sched.o.before 25725 2666 96 28487 6f47 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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