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2011-12-08sched, nohz: Fix missing RCU read lockPeter Zijlstra
Yong Zhang reported: > [ INFO: suspicious RCU usage. ] > kernel/sched/fair.c:5091 suspicious rcu_dereference_check() usage! This is due to the sched_domain stuff being RCU protected and commit 0b005cf5 ("sched, nohz: Implement sched group, domain aware nohz idle load balancing") overlooking this fact. The sd variable only lives inside the for_each_domain() block, so we only need to wrap that. Reported-by: Yong Zhang <yong.zhang0@gmail.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1323264728.32012.107.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Set the NOHZ_BALANCE_KICK flag for idle load balancerSuresh Siddha
Intention is to set the NOHZ_BALANCE_KICK flag for the 'ilb_cpu'. Not for the 'cpu' which is the local cpu. Fix the typo. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1323199594.1984.18.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Fix the idle cpu check in nohz_idle_balanceSuresh Siddha
cpu bit in the nohz.idle_cpu_mask are reset in the first busy tick after exiting idle. So during nohz_idle_balance(), intention is to double check if the cpu that is part of the idle_cpu_mask is indeed idle before going ahead in performing idle balance for that cpu. Fix the cpu typo in the idle_cpu() check during nohz_idle_balance(). Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1323199177.1984.12.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Use jump_labels for sched_featPeter Zijlstra
Now that we initialize jump_labels before sched_init() we can use them for the debug features without having to worry about a window where they have the wrong setting. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-vpreo4hal9e0kzqmg5y0io2k@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/accounting: Fix parameter passing in task_group_account_fieldGlauber Costa
The order of parameters is inverted. The index parameter should come first. Signed-off-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322863119-14225-3-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/accounting: Fix user/system tick double accountingGlauber Costa
Now that we're pointing cpuacct's root cgroup to cpustat and accounting through task_group_account_field(), we should not access cpustat directly. Since it is done anyway inside the acessor function, we end up accounting it twice, which is wrong. Signed-off-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322863119-14225-2-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/accounting: Re-use scheduler statistics for the root cgroupGlauber Costa
Right now, after we collect tick statistics for user and system and store them in a well known location, we keep the same statistics again for cpuacct. Since cpuacct is hierarchical, the numbers for the root cgroup should be absolutely equal to the system-wide numbers. So it would be better to just use it: this patch changes cpuacct accounting in a way that the cpustat statistics are kept in a struct kernel_cpustat percpu array. In the root cgroup case, we just point it to the main array. The rest of the hierarchy walk can be totally disabled later with a static branch - but I am not doing it here. Signed-off-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Tuner <pjt@google.com> Link: http://lkml.kernel.org/r/1322498719-2255-4-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Save some hrtick_start_fair cyclesMike Galbraith
hrtick_start_fair() shows up in profiles even when disabled. v3.0.6 taskset -c 3 pipe-test PerfTop: 997 irqs/sec kernel:89.5% exact: 0.0% [1000Hz cycles], (all, CPU: 3) ------------------------------------------------------------------------------------------------ Virgin Patched samples pcnt function samples pcnt function _______ _____ ___________________________ _______ _____ ___________________________ 2880.00 10.2% __schedule 3136.00 11.3% __schedule 1634.00 5.8% pipe_read 1615.00 5.8% pipe_read 1458.00 5.2% system_call 1534.00 5.5% system_call 1382.00 4.9% _raw_spin_lock_irqsave 1412.00 5.1% _raw_spin_lock_irqsave 1202.00 4.3% pipe_write 1255.00 4.5% copy_user_generic_string 1164.00 4.1% copy_user_generic_string 1241.00 4.5% __switch_to 1097.00 3.9% __switch_to 929.00 3.3% mutex_lock 872.00 3.1% mutex_lock 846.00 3.0% mutex_unlock 687.00 2.4% mutex_unlock 804.00 2.9% pipe_write 682.00 2.4% native_sched_clock 713.00 2.6% native_sched_clock 643.00 2.3% system_call_after_swapgs 653.00 2.3% _raw_spin_unlock_irqrestore 617.00 2.2% sched_clock_local 633.00 2.3% fsnotify 612.00 2.2% fsnotify 605.00 2.2% sched_clock_local 596.00 2.1% _raw_spin_unlock_irqrestore 593.00 2.1% system_call_after_swapgs 542.00 1.9% sysret_check 559.00 2.0% sysret_check 467.00 1.7% fget_light 472.00 1.7% fget_light 462.00 1.6% finish_task_switch 461.00 1.7% finish_task_switch 437.00 1.5% vfs_write 442.00 1.6% vfs_write 431.00 1.5% do_sync_write 428.00 1.5% do_sync_write 413.00 1.5% select_task_rq_fair 404.00 1.5% _raw_spin_lock_irq 386.00 1.4% update_curr 402.00 1.4% update_curr 385.00 1.4% rw_verify_area 389.00 1.4% do_sync_read 377.00 1.3% _raw_spin_lock_irq 378.00 1.4% vfs_read 369.00 1.3% do_sync_read 340.00 1.2% pipe_iov_copy_from_user 360.00 1.3% vfs_read 316.00 1.1% __wake_up_sync_key * 342.00 1.2% hrtick_start_fair 313.00 1.1% __wake_up_common Signed-off-by: Mike Galbraith <efault@gmx.de> [ fixed !CONFIG_SCHED_HRTICK borkage ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321971607.6855.17.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Fix compile error for UP,!NOHZPeter Zijlstra
Commit 69e1e811 ("sched, nohz: Track nr_busy_cpus in the sched_group_power") messed up the static inline function definition. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/n/tip-abjah8ctq5qrjjtdiabe8lph@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/accounting, cgroups: Reuse cgroup's parent pointerGlauber Costa
We already have a pointer to the cgroup parent (whose data is more likely to be in the cache than this, anyway), so there is no need to have this one in cpuacct. This patch makes the underlying cgroup be used instead. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Tuner <pjt@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322498719-2255-3-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/accounting: Change cpustat fields to an arrayGlauber Costa
This patch changes fields in cpustat from a structure, to an u64 array. Math gets easier, and the code is more flexible. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Tuner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322498719-2255-2-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Clean up the find_new_ilb() using sched groups nr_busy_cpusSuresh Siddha
nr_busy_cpus in the sched_group_power indicates whether the group is semi idle or not. This helps remove the is_semi_idle_group() and simplify the find_new_ilb() in the context of finding an optimal cpu that can do idle load balancing. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20111202010832.656983582@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Implement sched group, domain aware nohz idle load balancingSuresh Siddha
When there are many logical cpu's that enter and exit idle often, members of the global nohz data structure are getting modified very frequently causing lot of cache-line contention. Make the nohz idle load balancing more scalabale by using the sched domain topology and 'nr_busy_cpu's in the struct sched_group_power. Idle load balance is kicked on one of the idle cpu's when there is atleast one idle cpu and: - a busy rq having more than one task or - a busy rq's scheduler group that share package resources (like HT/MC siblings) and has more than one member in that group busy or - for the SD_ASYM_PACKING domain, if the lower numbered cpu's in that domain are idle compared to the busy ones. This will help in kicking the idle load balancing request only when there is a potential imbalance. And once it is mostly balanced, these kicks will be minimized. These changes helped improve the workload that is context switch intensive between number of task pairs by 2x on a 8 socket NHM-EX based system. Reported-by: Tim Chen <tim.c.chen@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Track nr_busy_cpus in the sched_group_powerSuresh Siddha
Introduce nr_busy_cpus in the struct sched_group_power [Not in sched_group because sched groups are duplicated for the SD_OVERLAP scheduler domain] and for each cpu that enters and exits idle, this parameter will be updated in each scheduler group of the scheduler domain that this cpu belongs to. To avoid the frequent update of this state as the cpu enters and exits idle, the update of the stat during idle exit is delayed to the first timer tick that happens after the cpu becomes busy. This is done using NOHZ_IDLE flag in the struct rq's nohz_flags. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20111202010832.555984323@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched, nohz: Introduce nohz_flags in 'struct rq'Suresh Siddha
Introduce nohz_flags in the struct rq, which will track these two flags for now. NOHZ_TICK_STOPPED keeps track of the tick stopped status that gets set when the tick is stopped. It will be used to update the nohz idle load balancer data structures during the first busy tick after the tick is restarted. At this first busy tick after tickless idle, NOHZ_TICK_STOPPED flag will be reset. This will minimize the nohz idle load balancer status updates that currently happen for every tickless exit, making it more scalable when there are many logical cpu's that enter and exit idle often. NOHZ_BALANCE_KICK will track the need for nohz idle load balance on this rq. This will replace the nohz_balance_kick in the rq, which was not being updated atomically. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20111202010832.499438999@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched/rt: Code cleanup, remove a redundant function callShan Hai
The second call to sched_rt_period() is redundant, because the value of the rt_runtime was already read and it was protected by the ->rt_runtime_lock. Signed-off-by: Shan Hai <haishan.bai@gmail.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322535836-13590-2-git-send-email-haishan.bai@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Fix the sched group node allocation for SD_OVERLAP domainsSuresh Siddha
For the SD_OVERLAP domain, sched_groups for each CPU's sched_domain are privately allocated and not shared with any other cpu. So the sched group allocation should come from the cpu's node for which SD_OVERLAP sched domain is being setup. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111118230554.164910950@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Set skip_clock_update in yield_task_fair()Mike Galbraith
This is another case where we are on our way to schedule(), so can save a useless clock update and resulting microscopic vruntime update. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321971686.6855.18.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Use rt.nr_cpus_allowed to recover select_task_rq() cyclesMike Galbraith
rt.nr_cpus_allowed is always available, use it to bail from select_task_rq() when only one cpu can be used, and saves some cycles for pinned tasks. See the line marked with '*' below: # taskset -c 3 pipe-test PerfTop: 997 irqs/sec kernel:89.5% exact: 0.0% [1000Hz cycles], (all, CPU: 3) ------------------------------------------------------------------------------------------------ Virgin Patched samples pcnt function samples pcnt function _______ _____ ___________________________ _______ _____ ___________________________ 2880.00 10.2% __schedule 3136.00 11.3% __schedule 1634.00 5.8% pipe_read 1615.00 5.8% pipe_read 1458.00 5.2% system_call 1534.00 5.5% system_call 1382.00 4.9% _raw_spin_lock_irqsave 1412.00 5.1% _raw_spin_lock_irqsave 1202.00 4.3% pipe_write 1255.00 4.5% copy_user_generic_string 1164.00 4.1% copy_user_generic_string 1241.00 4.5% __switch_to 1097.00 3.9% __switch_to 929.00 3.3% mutex_lock 872.00 3.1% mutex_lock 846.00 3.0% mutex_unlock 687.00 2.4% mutex_unlock 804.00 2.9% pipe_write 682.00 2.4% native_sched_clock 713.00 2.6% native_sched_clock 643.00 2.3% system_call_after_swapgs 653.00 2.3% _raw_spin_unlock_irqrestore 617.00 2.2% sched_clock_local 633.00 2.3% fsnotify 612.00 2.2% fsnotify 605.00 2.2% sched_clock_local 596.00 2.1% _raw_spin_unlock_irqrestore 593.00 2.1% system_call_after_swapgs 542.00 1.9% sysret_check 559.00 2.0% sysret_check 467.00 1.7% fget_light 472.00 1.7% fget_light 462.00 1.6% finish_task_switch 461.00 1.7% finish_task_switch 437.00 1.5% vfs_write 442.00 1.6% vfs_write 431.00 1.5% do_sync_write 428.00 1.5% do_sync_write * 413.00 1.5% select_task_rq_fair 404.00 1.5% _raw_spin_lock_irq 386.00 1.4% update_curr 402.00 1.4% update_curr 385.00 1.4% rw_verify_area 389.00 1.4% do_sync_read 377.00 1.3% _raw_spin_lock_irq 378.00 1.4% vfs_read 369.00 1.3% do_sync_read 340.00 1.2% pipe_iov_copy_from_user 360.00 1.3% vfs_read 316.00 1.1% __wake_up_sync_key 342.00 1.2% hrtick_start_fair 313.00 1.1% __wake_up_common Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321971504.6855.15.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06sched: Clean up domain traversal in select_idle_sibling()Suresh Siddha
Instead of going through the scheduler domain hierarchy multiple times (for giving priority to an idle core over an idle SMT sibling in a busy core), start with the highest scheduler domain with the SD_SHARE_PKG_RESOURCES flag and traverse the domain hierarchy down till we find an idle group. This cleanup also addresses an issue reported by Mike where the recent changes returned the busy thread even in the presence of an idle SMT sibling in single socket platforms. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321556904.15339.25.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06events, sched: Add tracepoint for accounting blocked timeAndrew Vagin
This tracepoint shows how long a task is sleeping in uninterruptible state. E.g. it may show how long and where a mutex is waited for. Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322471015-107825-8-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-17sched: Move all scheduler bits into kernel/sched/Peter Zijlstra
There's too many sched*.[ch] files in kernel/, give them their own directory. (No code changed, other than Makefile glue added.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-17sched: Make separate sched*.c translation unitsPeter Zijlstra
Since once needs to do something at conferences and fixing compile warnings doesn't actually require much if any attention I decided to break up the sched.c #include "*.c" fest. This further modularizes the scheduler code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-x0fcd3mnp8f9c99grcpewmhi@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched: Fix comment for requeue_rt_entityRichard Weinberger
Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321117677-3282-1-git-send-email-richard@nod.at Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched: Don't call task_group() too many times in set_task_rq()Andrew Vagin
It improves perfomance, especially if autogroup is enabled. The size of set_task_rq() was 0x180 and now it is 0xa0. Signed-off-by: Andrew Vagin <avagin@openvz.org> Acked-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1321020240-3874331-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched, trivial: Initialize root cgroup's sibling listGlauber Costa
Even though there are no siblings, the list should be initialized to not contain bogus values. Signed-off-by: Glauber Costa <glommer@parallels.com> Acked-by: Paul Menage <paul@paulmenage.org> Acked-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1320182360-20043-2-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched: Use jump labels to reduce overhead when bandwidth control is inactivePaul Turner
Now that the linkage of jump-labels has been fixed they show a measurable improvement in overhead for the enabled-but-unused case. Workload is: 'taskset -c 0 perf stat --repeat 50 -e instructions,cycles,branches bash -c "for ((i=0;i<5;i++)); do $(dirname $0)/pipe-test 20000; done"' There's a speedup for all situations: instructions cycles branches ------------------------------------------------------------------------- Intel Westmere base 806611770 745895590 146765378 +jumplabel 803090165 (-0.44%) 713381840 (-4.36%) 144561130 AMD Barcelona base 824657415 740055589 148855354 +jumplabel 821056910 (-0.44%) 737558389 (-0.34%) 146635229 Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111108042736.560831357@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched: Fix buglet in return_cfs_rq_runtime()Paul Turner
In return_cfs_rq_runtime() we want to return bandwidth when there are no remaining tasks, not "return" when this is the case. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111108042736.623812423@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16sched: Avoid SMT siblings in select_idle_sibling() if possiblePeter Zijlstra
Avoid select_idle_sibling() from picking a sibling thread if there's an idle core that shares cache. This fixes SMT balancing in the increasingly common case where there's a shared cache core available to balance to. Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1321350377.1421.55.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14sched: Set the command name of the idle tasks in SMP kernelsCarsten Emde
In UP systems, the idle task is initialized using the init_task structure from which the command name is taken (currently "swapper"). In SMP systems, one idle task per CPU is forked by the worker thread from which the task structure is copied. The command name is, therefore, "kworker/0:0" or "kworker/0:1", if not updated. Since such update was lacking, all idle tasks in SMP systems were incorrectly named. This longtime bug was not discovered immediately, because there is no /proc/0 entry - the bug only becomes apparent when tracing is enabled. This patch sets the command name of the idle tasks in SMP systems to the name that is used in the INIT_TASK structure suffixed by a slash and the number of the CPU. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111026211708.768925506@osadl.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14sched, rt: Provide means of disabling cross-cpu bandwidth sharingPeter Zijlstra
Normally the RT bandwidth scheme will share bandwidth across the entire root_domain. However sometimes its convenient to disable this sharing for debug purposes. Provide a simple feature switch to this end. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14sched: Document wait_for_completion_*() return valuesJ. Bruce Fields
The return-value convention for these functions varies depending on whether they're interruptible or can timeout. It can be a little confusing--document it. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111006192246.GB28026@fieldses.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14sched_fair: Fix a typo in the comment describing update_sd_lb_statsHui Kang
Signed-off-by: Hui Kang <hkang.sunysb@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1318388459-4427-1-git-send-email-hkang.sunysb@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14sched: Add a comment to effective_load() since it's a painPeter Zijlstra
Every time I have to stare at this function I need to completely reverse engineer its workings, about time I write a comment explaining the thing. Collected bits and pieces from previous changelogs, mostly: 4be9daaa1b33701f011f4117f22dc1e45a3e6e34 83378269a5fad98f562ebc0f09c349575e6cbfe1 Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1318518057.27731.2.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-14Merge branch 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-shLinus Torvalds
* 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-sh: ARM: mach-shmobile: cpuidle single/global and last_state fixes ARM: mach-shmobile: move helper macro PORTCR to sh_pfc.h ARM: mach-shmobile: move helper macro PORT_xx to sh_pfc.h ARM: mach-shmobile: move helper macro PORT_DATA_xx to sh_pfc.h ARM: mach-shmobile: ap4evb: remove white space from end of line ARM: mach-shmobile: clock-sh7372: remove un-necessary index ARM: mach-shmobile: kota2: add comment out separator ARM: mach-shmobile: sh73a0: add MMC data pin pull-up
2011-11-14Merge branch 'sh-fixes-for-linus' of git://github.com/pmundt/linux-shLinus Torvalds
* 'sh-fixes-for-linus' of git://github.com/pmundt/linux-sh: mailmap: Fix up some renesas attributions sh: clkfwk: Kill off remaining debugfs cruft. drivers: sh: Kill off dead pathname for runtime PM stub. drivers: sh: Generalize runtime PM platform stub. sh: Wire up process_vm syscalls. sh: clkfwk: add clk_rate_mult_range_round() serial: sh-sci: Fix up SH-2A SCIF support. sh: Fix cached/uncaced address calculation in 29bit mode
2011-11-14Merge git://github.com/rustyrussell/linuxLinus Torvalds
* git://github.com/rustyrussell/linux: virtio-pci: fix use after free
2011-11-14virtio-pci: fix use after freeMichael S. Tsirkin
Commit 31a3ddda166cda86d2b5111e09ba4bda5239fae6 introduced a use after free in virtio-pci. The main issue is that the release method signals removal of the virtio device, while remove signals removal of the pci device. For example, on driver removal or hot-unplug, virtio_pci_release_dev is called before virtio_pci_remove. We then might get a crash as virtio_pci_remove tries to use the device freed by virtio_pci_release_dev. We allocate/free all resources together with the pci device, so we can leave the release method empty. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2011-11-13Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/radeon/kms/combios: fix dynamic allocation of PM clock modes
2011-11-12ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression)Rafael J. Wysocki
After commit e978aa7d7d57 ("cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state") setting acpi_idle_suspend to 1 by acpi_processor_suspend() causes the ACPI cpuidle routines to return error codes continuously, which in turn causes cpuidle to lock up (hard). However, acpi_idle_suspend doesn't appear to be useful for any particular purpose (it's racy and doesn't really provide any real protection), so it can be removed, which makes the problem go away. Reported-and-tested-by: Tomas M. <tmezzadra@gmail.com> Reported-and-tested-by: Ferenc Wagner <wferi@niif.hu> Tested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-12drm/radeon/kms/combios: fix dynamic allocation of PM clock modesAlex Deucher
I missed the combios path when I updated the atombios pm code. Reported by amarsh04 on IRC. Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-11-12Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: arm/imx: fix imx6q mmc error when mounting rootfs arm/imx: fix AUTO_ZRELADDR selection arm/imx: fix the references to ARCH_MX3 ARM: mx51/53: set pwm clock parent to ipg_perclk arm/tegra: enable headphone detection gpio on seaboard arm/dt: Fix ventana SDHCI power-gpios arm/tegra: Don't create duplicate gpio and pinmux devices ARM: at91: Fix USBA gadget registration atmel/spi: fix missing probe at91/yl-9200: Fix section mismatch at91: vmalloc fix missing AT91_VIRT_BASE define ARM: at91: usart: drop static map regs for dbgu ARM: picoxcell: add extra temp register to addruart ARM: msm: fix compilation flags for MSM_SCM arm/mxs: fix mmc device adding for mach-mx28evk ARM: mxc: Remove test_for_ltirq ARM:i.MX: fix build error in clock-mx51-mx53.c ARM:i.MX: fix build error in tzic/avic.c ARM: mxc: fix local timer interrupt handling msm: boards: Fix fallout from removal of machine_desc in fixup
2011-11-11[CPUFREQ] db8500: fix build error due to undeclared i variableAxel Lin
The variable i is removed by commit ded8433 "[CPUFREQ] db8500: remove unneeded for loop iteration over freq_table", but current code to print available frequencies still uses the i variable. Thus add the i variable back to fix below buld error: CC drivers/cpufreq/db8500-cpufreq.o drivers/cpufreq/db8500-cpufreq.c: In function 'db8500_cpufreq_init': drivers/cpufreq/db8500-cpufreq.c:123: error: 'i' undeclared (first use in this function) drivers/cpufreq/db8500-cpufreq.c:123: error: (Each undeclared identifier is reported only once drivers/cpufreq/db8500-cpufreq.c:123: error: for each function it appears in.) make[2]: *** [drivers/cpufreq/db8500-cpufreq.o] Error 1 make[1]: *** [drivers/cpufreq] Error 2 make: *** [drivers] Error 2 This patch also fixes using uninitialized i variable as array index. Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Dave Jones <davej@redhat.com>
2011-11-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: (29 commits) m68k/mac: Remove mac_irq_{en,dis}able() wrappers m68k/irq: Remove obsolete support for user vector interrupt fixups m68k/irq: Remove obsolete m68k irq framework m68k/q40: Convert Q40/Q60 to genirq m68k/sun3: Convert Sun3/3x to genirq m68k/sun3: Use the kstat_irqs_cpu() wrapper m68k/apollo: Convert Apollo to genirq m68k/vme: Convert VME to genirq m68k/hp300: Convert HP9000/300 and HP9000/400 to genirq m68k/mac: Optimize interrupts using chain handlers m68k/mac: Convert Mac to genirq m68k/amiga: Optimize interrupts using chain handlers m68k/amiga: Convert Amiga to genirq m68k/amiga: Refactor amiints.c m68k/atari: Remove code and comments about different irq types m68k/atari: Convert Atari to genirq m68k/irq: Add genirq support m68k/irq: Remove obsolete IRQ_FLG_* users m68k/irq: Rename {,__}m68k_handle_int() m68k/irq: Add m68k_setup_irq_controller() ...
2011-11-12Merge branch 'v4l_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] v4l2-ctrl: Send change events to all fh for auto cluster slave controls [media] v4l2-event: Don't set sev->fh to NULL on unsubscribe [media] v4l2-event: Remove pending events from fh event queue when unsubscribing [media] v4l2-event: Deny subscribing with a type of V4L2_EVENT_ALL [media] MAINTAINERS: add a maintainer for s5p-mfc driver [media] v4l: s5p-mfc: fix reported capabilities [media] media: vb2: reset queued list on REQBUFS(0) call [media] media: vb2: set buffer length correctly for all buffer types [media] media: vb2: add a check for uninitialized buffer [media] mxl111sf: fix build warning [media] mxl111sf: remove pointless if condition in mxl111sf_config_spi [media] mxl111sf: check for errors after mxl111sf_write_reg in mxl111sf_idac_config [media] mxl111sf: fix return value of mxl111sf_idac_config [media] uvcvideo: GET_RES should only be checked for BITMAP type menu controls
2011-11-12Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/kvm: Fix build failure with HV KVM and CBE powerpc/ps3: Fix lv1_gpu_attribute hcall powerpc/ps3: Fix PS3 repository build warnings powerpc/ps3: irq: Remove IRQF_DISABLED powerpc/irq: Remove IRQF_DISABLED powerpc/numa: NUMA topology support for PowerNV powerpc: Add System RAM to /proc/iomem powerpc: Add KVM as module to defconfigs powerpc/kvm: Fix build with older toolchains powerpc, tqm5200: update tqm5200_defconfig to fit for charon board. powerpc/5200: add support for charon board
2011-11-11Merge branch 'rc-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild * 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: Fix missing system calls check on mips.
2011-11-11bma023: Add SFI translation for this deviceWilliam Douglas
This needed the sfi IRQ 0xFF fix to go in first. It simply plumbs in the bma023 driver with the firmware naming of it. Signed-off-by: William Douglas <william.douglas@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-11vrtc: change its year offset from 1960 to 1972Feng Tang
Real world year equals the value in vrtc YEAR register plus an offset. We used 1960 as the offset to make leap year consistent, but for a device's first use, its YEAR register is 0 and the system year will be parsed as 1960 which is not a valid UNIX time and will cause many applications to fail mysteriously. So we use 1972 instead to fix this issue. Updated patch which adds a sanity check suggested by Mathias This isn't a change in behaviour for systems, because 1972 is the one we actually use. It's the old version in upstream which is out of sync with all devices. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-11ce4100: fix a build errorZhang Rui
Fix a build error. CE4100 with no serial errors because the alternate function is only a prototype not a null function as intended. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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