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| * | sched: Rename ttwu_post_activation() to ttwu_do_wakeup()Peter Zijlstra2011-04-141-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ttwu_post_activation() code does the core wakeup, it sets TASK_RUNNING and performs wakeup-preemption, so give is a more descriptive name. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.434609705@chello.nl
| * | sched: Remove rq argument from ttwu_stat()Peter Zijlstra2011-04-141-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to call ttwu_stat() without holding rq->lock we must remove its rq argument. Since we need to change rq stats, account to the local rq instead of the task rq, this is safe since we have IRQs disabled. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl
| * | sched: Remove rq->lock from the first half of ttwu()Peter Zijlstra2011-04-141-28/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
| * | sched: Drop rq->lock from sched_exec()Peter Zijlstra2011-04-141-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we can now call select_task_rq() and set_task_cpu() with only p->pi_lock held, and sched_exec() load-balancing has always been optimistic, drop all rq->lock usage. Oleg also noted that need_migrate_task() will always be true for current, so don't bother calling that at all. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.314204889@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Drop rq->lock from first part of wake_up_new_task()Peter Zijlstra2011-04-141-14/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since p->pi_lock now protects all things needed to call select_task_rq() avoid the double remote rq->lock acquisition and rely on p->pi_lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.273362517@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Add p->pi_lock to task_rq_lock()Peter Zijlstra2011-04-141-56/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Also serialize ttwu_local() with p->pi_lockPeter Zijlstra2011-04-141-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
| * | sched: Delay task_contributes_to_load()Peter Zijlstra2011-04-141-12/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In prepratation of having to call task_contributes_to_load() without holding rq->lock, we need to store the result until we do and can update the rq accounting accordingly. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.151523907@chello.nl
| * | sched: Deal with non-atomic min_vruntime reads on 32bitsPeter Zijlstra2011-04-141-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid reading partial updated min_vruntime values on 32bit implement a seqcount like solution. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.111378493@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Remove rq argument to sched_class::task_waking()Peter Zijlstra2011-04-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of calling this without rq->lock held, remove the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.071474242@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Drop the rq argument to sched_class::select_task_rq()Peter Zijlstra2011-04-141-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of calling select_task_rq() without rq->lock held, drop the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Serialize p->cpus_allowed and ttwu() using p->pi_lockPeter Zijlstra2011-04-141-21/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Provide p->on_rqPeter Zijlstra2011-04-141-18/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
| * | sched: Clean up ttwu() statsPeter Zijlstra2011-04-141-35/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
| * | sched: Change the ttwu() success detailsPeter Zijlstra2011-04-141-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_to_wake_up() would only return a success when it would have to place a task on a rq, change that to every time we change p->state to TASK_RUNNING, because that's the real measure of wakeups. This results in that success is always true for the tracepoints. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.866866929@chello.nl
| * | sched: Move wq_worker_waking to the correct sitePeter Zijlstra2011-04-141-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wq_worker_waking_up() needs to match wq_worker_sleeping(), since the latter is only called on deactivate, move the former near activate. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/n/top-t3m7n70n9frmv4pv2n5fwmov@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | mutex: Use p->on_cpu for the adaptive spinPeter Zijlstra2011-04-141-50/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
| * | sched: Always provide p->on_cpuPeter Zijlstra2011-04-141-17/+29
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * block: don't flush plugged IO on forced preemtion schedulingLinus Torvalds2011-04-131-10/+10
| | | | | | | | | | | | | | | | | | | | | | We really only want to unplug the pending IO when the process actually goes to sleep. So move the test for flushing the plug up to the place where we actually deactivate the task - where we have properly checked for preemption and for the process really sleeping. Acked-by: Jens Axboe <jaxboe@fusionio.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | sched: Dynamic sched_domain::levelPeter Zijlstra2011-04-111-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | Remove the SD_LV_ enum and use dynamic level assignments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.969433965@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Move sched domain storage into the topology listPeter Zijlstra2011-04-111-52/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Reverse the topology listPeter Zijlstra2011-04-111-14/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Unify the sched_domain build functionsPeter Zijlstra2011-04-111-94/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Stuff the sched_domain creation in a data-structurePeter Zijlstra2011-04-111-6/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Create proper cpu_$DOM_mask() functionsPeter Zijlstra2011-04-111-5/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to unify the sched domain creation more, create proper cpu_$DOM_mask() functions for those domains that didn't already have one. Use the sched_domains_tmpmask for the weird NUMA domain span. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.717702108@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Avoid allocations in sched_domain_debug()Peter Zijlstra2011-04-111-12/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we're all serialized by sched_domains_mutex we can use sched_domains_tmpmask and avoid having to do allocations. This means we can use sched_domains_debug() for cpu_attach_domain() again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.664347467@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Create persistent sched_domains_tmpmaskPeter Zijlstra2011-04-111-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since sched domain creation is fully serialized by the sched_domains_mutex we can create a single persistent tmpmask to use during domain creation. This removes the need for s_data::send_covered. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.607287405@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Remove some dead codePeter Zijlstra2011-04-111-16/+0
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.553814623@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Remove nodemask allocationPeter Zijlstra2011-04-111-11/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There's only one nodemask user left so remove it with a direct computation and save some memory and reduce some code-flow complexity. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.505608966@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify NODE/ALLNODES domain creationPeter Zijlstra2011-04-111-18/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't treat ALLNODES/NODE different for difference's sake. Simply always create the ALLNODES domain and let the sd_degenerate() checks kill it when its redundant. This simplifies the code flow. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.455464579@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify the free path somePeter Zijlstra2011-04-111-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If we check the root_domain reference count we can see if its been used or not, use this observation to simplify some of the return paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Dynamically allocate sched_domain/sched_group data-structuresPeter Zijlstra2011-04-111-290/+189
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify sched_groups_power initializationPeter Zijlstra2011-04-111-34/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Again, instead of relying on knowing the possible domains and their order, simply rely on the sched_domain tree and whatever domains are present in there to initialize the sched_group cpu_power. Note: we need to iterate the CPU mask backwards because of the cpumask_first() condition for iterating up the tree. By iterating the mask backwards we ensure all groups of a domain are set-up before starting on the parent groups that rely on its children to be completely done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.187335414@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify finding the lowest sched_domainPeter Zijlstra2011-04-111-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify sched_group creationPeter Zijlstra2011-04-111-19/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of calling build_sched_groups() for each possible sched_domain we might have created, note that we can simply iterate the sched_domain tree and call it for each sched_domain present. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.077862519@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Clean up some ALLNODES codePeter Zijlstra2011-04-111-7/+4
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.025636011@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Change NODE sched_domain group creationPeter Zijlstra2011-04-111-197/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The NODE sched_domain is 'special' in that it allocates sched_groups per CPU, instead of sharing the sched_groups between all CPUs. While this might have some benefits on large NUMA and avoid remote memory accesses when iterating the sched_groups, this does break current code that assumes sched_groups are shared between all sched_domains (since the dynamic cpu_power patches). So refactor the NODE groups to behave like all other groups. (The ALLNODES domain again shared its groups across the CPUs for some reason). If someone does measure a performance decrease due to this change we need to revisit this and come up with another way to have both dynamic cpu_power and NUMA work nice together. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.978111700@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify build_sched_groups()Peter Zijlstra2011-04-111-36/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Notice that the mask being computed is the same as the domain span we just computed. By using the domain_span we can avoid some mask allocations and computations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.925028189@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Simplify ->cpu_power initializationPeter Zijlstra2011-04-111-39/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code in update_group_power() does what init_sched_groups_power() does and more, so remove the special init_ code and call the generic code instead. Also move the sd->span_weight initialization because update_group_power() needs it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.875856012@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sched: Remove obsolete arch_ prefixesPeter Zijlstra2011-04-111-7/+7
|/ | | | | | | | | | | | | Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
*---. Merge branches 'x86-fixes-for-linus', 'sched-fixes-for-linus', ↵Linus Torvalds2011-04-071-0/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'timers-fixes-for-linus', 'irq-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-32, fpu: Fix FPU exception handling on non-SSE systems x86, hibernate: Initialize mmu_cr4_features during boot x86-32, NUMA: Fix ACPI NUMA init broken by recent x86-64 change x86: visws: Fixup irq overhaul fallout * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Clean up rebalance_domains() load-balance interval calculation * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86/mrst/vrtc: Fix boot crash in mrst_rtc_init() rtc, x86/mrst/vrtc: Fix boot crash in rtc_read_alarm() * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix cpumask leak in __setup_irq() * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf probe: Fix listing incorrect line number with inline function perf probe: Fix to find recursively inlined function perf probe: Fix multiple --vars options behavior perf probe: Fix to remove redundant close perf probe: Fix to ensure function declared file
| | * | sched: Clean up rebalance_domains() load-balance interval calculationPeter Zijlstra2011-04-051-0/+3
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of the possible multiple-evaluation of num_online_cpus() in rebalance_domains() that Linus reported, avoid it altogether in the normal case since it's implemented with a Hamming weight function over a cpu bitmask which can be darn expensive for those with big iron. This also makes it cleaner, smaller and documents the code. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1301991265.2225.12.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6Linus Torvalds2011-04-071-3/+3
|\ \ \ | |_|/ |/| | | | | | | | * 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6: Fix common misspellings
| * | Fix common misspellingsLucas De Marchi2011-03-311-3/+3
| |/ | | | | | | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* | sched: Leave sched_setscheduler() earlier if possible, do not disturb ↵Dario Faggioli2011-03-311-0/+11
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SCHED_FIFO tasks sched_setscheduler() (in sched.c) is called in order of changing the scheduling policy and/or the real-time priority of a task. Thus, if we find out that neither of those are actually being modified, it is possible to return earlier and save the overhead of a full deactivate+activate cycle of the task in question. Beside that, if we have more than one SCHED_FIFO task with the same priority on the same rq (which means they share the same priority queue) having one of them changing its position in the priority queue because of a sched_setscheduler (as it happens by means of the deactivate+activate) that does not actually change the priority violates POSIX which states, for SCHED_FIFO: "If a thread whose policy or priority has been modified by pthread_setschedprio() is a running thread or is runnable, the effect on its position in the thread list depends on the direction of the modification, as follows: a. <...> b. If the priority is unchanged, the thread does not change position in the thread list. c. <...>" http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html (ed: And the POSIX specification here does, briefly and somewhat unexpectedly, match what common sense tells us as well. ) Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1300971618.3960.82.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2011-03-251-3/+2
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched, doc: Update sched-design-CFS.txt sched: Remove unused 'rq' variable and cpu_rq() call from alloc_fair_sched_group() sched.h: Fix a typo ("its") sched: Fix yield_to kernel-doc
| * sched: Remove unused 'rq' variable and cpu_rq() call from ↵Sergey Senozhatsky2011-03-231-3/+0
| | | | | | | | | | | | | | | | | | | | alloc_fair_sched_group() Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110323111722.GA4244@swordfish.minsk.epam.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: Fix yield_to kernel-docRandy Dunlap2011-03-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Add missing function parameters for yield_to(): Warning(kernel/sched.c:5470): No description found for parameter 'p' Warning(kernel/sched.c:5470): No description found for parameter 'preempt' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110318093453.8f7489a4.randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched, kernel-doc: Fix runqueue_is_locked() descriptionRandy Dunlap2011-03-161-2/+1
| | | | | | | | | | | | | | | | | | | | | | Fix kernel-doc warning for runqueue_is_locked(): Warning(kernel/sched.c:664): missing initial short description Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110315161230.c4e1e8e3.rdunlap@xenotime.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2011-03-241-0/+12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
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