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| | * | | | | | | | sched: Calculate energy consumption of sched_groupMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For energy-aware load-balancing decisions it is necessary to know the energy consumption estimates of groups of cpus. This patch introduces a basic function, sched_group_energy(), which estimates the energy consumption of the cpus in the group and any resources shared by the members of the group. NOTE: The function has five levels of identation and breaks the 80 character limit. Refactoring is necessary. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Highest energy aware balancing sched_domain level pointerMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add another member to the family of per-cpu sched_domain shortcut pointers. This one, sd_ea, points to the highest level at which energy model is provided. At this level and all levels below all sched_groups have energy model data attached. Partial energy model information is possible but restricted to providing energy model data for lower level sched_domains (sd_ea and below) and leaving load-balancing on levels above to non-energy-aware load-balancing. For example, it is possible to apply energy-aware scheduling within each socket on a multi-socket system and let normal scheduling handle load-balancing between sockets. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Relocated cpu_util() and change return typeMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move cpu_util() to an earlier position in fair.c and change return type to unsigned long as negative usage doesn't make much sense. All other load and capacity related functions use unsigned long including the caller of cpu_util(). cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Compute cpu capacity available at current frequencyMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | capacity_orig_of() returns the max available compute capacity of a cpu. For scale-invariant utilization tracking and energy-aware scheduling decisions it is useful to know the compute capacity available at the current OPP of a cpu. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Introduce SD_SHARE_CAP_STATES sched_domain flagMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq is currently keeping it a secret which cpus are sharing clock source. The scheduler needs to know about clock domains as well to become more energy aware. The SD_SHARE_CAP_STATES domain flag indicates whether cpus belonging to the sched_domain share capacity states (P-states). There is no connection with cpufreq (yet). The flag must be set by the arch specific topology code. cc: Russell King <linux@arm.linux.org.uk> cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Initialize energy data structuresDietmar Eggemann2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sched_group_energy (sge) pointer of the first sched_group (sg) in the sched_domain (sd) is initialized to point to the appropriate (in terms of sd level and cpu) sge data defined in the arch and so to the correct part of the Energy Model (EM). Energy-aware scheduling allows that a system has only EM data up to a certain sd level (so called highest energy aware balancing sd level). A check in init_sched_energy() enforces that all sd's below this sd level contain EM data. The 'int cpu' parameter of sched_domain_energy_f requires that check_sched_energy_data() makes sure that all cpus spanned by a sg are provisioned with the same EM data. This patch has also been tested with feature FORCE_SD_OVERLAP enabled. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| | * | | | | | | | sched: Introduce energy data structuresDietmar Eggemann2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The struct sched_group_energy represents the per sched_group related data which is needed for energy aware scheduling. It contains: (1) number of elements of the idle state array (2) pointer to the idle state array which comprises 'power consumption' for each idle state (3) number of elements of the capacity state array (4) pointer to the capacity state array which comprises 'compute capacity and power consumption' tuples for each capacity state The struct sched_group obtains a pointer to a struct sched_group_energy. The function pointer sched_domain_energy_f is introduced into struct sched_domain_topology_level which will allow the arch to pass a particular struct sched_group_energy from the topology shim layer into the scheduler core. The function pointer sched_domain_energy_f has an 'int cpu' parameter since the folding of two adjacent sd levels via sd degenerate doesn't work for all sd levels. I.e. it is not possible for example to use this feature to provide per-cpu energy in sd level DIE on ARM's TC2 platform. It was discussed that the folding of sd levels approach is preferable over the cpu parameter approach, simply because the user (the arch specifying the sd topology table) can introduce less errors. But since it is not working, the 'int cpu' parameter is the only way out. It's possible to use the folding of sd levels approach for sched_domain_flags_f and the cpu parameter approach for the sched_domain_energy_f at the same time though. With the use of the 'int cpu' parameter, an extra check function has to be provided to make sure that all cpus spanned by a sched group are provisioned with the same energy data. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| | * | | | | | | | sched: Make energy awareness a sched featureMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces the ENERGY_AWARE sched feature, which is implemented using jump labels when SCHED_DEBUG is defined. It is statically set false when SCHED_DEBUG is not defined. Hence this doesn't allow energy awareness to be enabled without SCHED_DEBUG. This sched_feature knob will be replaced later with a more appropriate control knob when things have matured a bit. ENERGY_AWARE is based on per-entity load-tracking hence FAIR_GROUP_SCHED must be enable. This dependency isn't checked at compile time yet. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Prevent unnecessary active balance of single task in sched groupMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scenarios with the busiest group having just one task and the local being idle on topologies with sched groups with different numbers of cpus manage to dodge all load-balance bailout conditions resulting the nr_balance_failed counter to be incremented. This eventually causes a pointless active migration of the task. This patch prevents this by not incrementing the counter when the busiest group only has one task. ASYM_PACKING migrations and migrations due to reduced capacity should still take place as these are explicitly captured by need_active_balance(). A better solution would be to not attempt the load-balance in the first place, but that requires significant changes to the order of bailout conditions and statistics gathering. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Enable idle balance to pull single task towards cpu with higher capacityDietmar Eggemann2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We do not want to miss out on the ability to pull a single remaining task from a potential source cpu towards an idle destination cpu. Add an extra criteria to need_active_balance() to kick off active load balance if the source cpu is over-utilized and has lower capacity than the destination cpu. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| | * | | | | | | | sched: Consider spare cpu capacity at task wake-upMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_idlest_group() selects the wake-up target group purely based on group load which leads to suboptimal choices in low load scenarios. An idle group with reduced capacity (due to RT tasks or different cpu type) isn't necessarily a better target than a lightly loaded group with higher capacity. The patch adds spare capacity as an additional group selection parameter. The target group is now selected based on the following criteria: 1. Return the group with the cpu with most spare capacity and this capacity is significant if such group exists. Significant spare capacity is currently at least 20% to spare. 2. Return the group with the lowest load, unless it is the local group in which case NULL is returned and the search is continued at the next (lower) level. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Add cpu capacity awareness to wakeup balancingMorten Rasmussen2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wakeup balancing is completely unaware of cpu capacity, cpu utilization and task utilization. The task is preferably placed on a cpu which is idle in the instant the wakeup happens. New tasks (SD_BALANCE_{FORK,EXEC} are placed on an idle cpu in the idlest group if such can be found, otherwise it goes on the least loaded one. Existing tasks (SD_BALANCE_WAKE) are placed on the previous cpu or an idle cpu sharing the same last level cache unless the wakee_flips heuristic in wake_wide() decides to fallback to considering cpus outside SD_LLC. Hence existing tasks are not guaranteed to get a chance to migrate to a different group at wakeup in case the current one has reduced cpu capacity (due RT/IRQ pressure or different uarch e.g. ARM big.LITTLE). They may eventually get pulled by other cpus doing periodic/idle/nohz_idle balance, but it may take quite a while before it happens. This patch adds capacity awareness to find_idlest_{group,queue} (used by SD_BALANCE_{FORK,EXEC} and SD_BALANCE_WAKE under certain circumstances) such that groups/cpus that can accommodate the waking task based on task utilization are preferred. In addition, wakeup of existing tasks (SD_BALANCE_WAKE) is sent through find_idlest_{group,queue} also if the task doesn't fit the capacity of the previous cpu to allow it to escape (override wake_affine) when necessary instead of relying on periodic/idle/nohz_idle balance to eventually sort it out. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| | * | | | | | | | sched: Store system-wide maximum cpu capacity in root domainDietmar Eggemann2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To be able to compare the capacity of the target cpu with the highest cpu capacity of the system in the wakeup path, store the system-wide maximum cpu capacity in the root domain. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| | * | | | | | | | sched/fair: Fix new task's load avg removed from source CPU in ↵Yuyang Du2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wake_up_new_task() If a newly created task is selected to go to a different CPU in fork balance when it wakes up the first time, its load averages should not be removed from the source CPU since they are never added to it before. The same is also applicable to a never used group entity. Fix it in remove_entity_load_avg(): when entity's last_update_time is 0, simply return. This should precisely identify the case in question, because in other migrations, the last_update_time is set to 0 after remove_entity_load_avg(). Reported-by: Steve Muckle <steve.muckle@linaro.org> Signed-off-by: Yuyang Du <yuyang.du@intel.com> [peterz: cfs_rq_last_update_time] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <Juri.Lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20151216233427.GJ28098@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | | | cpuset: Make cpusets restore on hotplugRiley Andrews2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This deliberately changes the behavior of the per-cpuset cpus file to not be effected by hotplug. When a cpu is offlined, it will be removed from the cpuset/cpus file. When a cpu is onlined, if the cpuset originally requested that that cpu was part of the cpuset, that cpu will be restored to the cpuset. The cpus files still have to be hierachical, but the ranges no longer have to be out of the currently online cpus, just the physically present cpus. Change-Id: I22cdf33e7d312117bcefba1aeb0125e1ada289a9 Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
| | * | | | | | | | ANDROID: rcu_sync: Export rcu_sync_lockdep_assertGuenter Roeck2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86_64:allmodconfig fails to build with the following error. ERROR: "rcu_sync_lockdep_assert" [kernel/locking/locktorture.ko] undefined! Introduced by commit 3228c5eb7af2 ("RFC: FROMLIST: locking/percpu-rwsem: Optimize readers and reduce global impact"). The applied upstream version exports the missing symbol, so let's do the same. Change-Id: If4e516715c3415fe8c82090f287174857561550d Fixes: 3228c5eb7af2 ("RFC: FROMLIST: locking/percpu-rwsem: Optimize ...") Signed-off-by: Guenter Roeck <groeck@chromium.org>
| | * | | | | | | | RFC: FROMLIST: cgroup: reduce read locked section of ↵Balbir Singh2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_threadgroup_rwsem during fork cgroup_threadgroup_rwsem is acquired in read mode during process exit and fork. It is also grabbed in write mode during __cgroups_proc_write(). I've recently run into a scenario with lots of memory pressure and OOM and I am beginning to see systemd __switch_to+0x1f8/0x350 __schedule+0x30c/0x990 schedule+0x48/0xc0 percpu_down_write+0x114/0x170 __cgroup_procs_write.isra.12+0xb8/0x3c0 cgroup_file_write+0x74/0x1a0 kernfs_fop_write+0x188/0x200 __vfs_write+0x6c/0xe0 vfs_write+0xc0/0x230 SyS_write+0x6c/0x110 system_call+0x38/0xb4 This thread is waiting on the reader of cgroup_threadgroup_rwsem to exit. The reader itself is under memory pressure and has gone into reclaim after fork. There are times the reader also ends up waiting on oom_lock as well. __switch_to+0x1f8/0x350 __schedule+0x30c/0x990 schedule+0x48/0xc0 jbd2_log_wait_commit+0xd4/0x180 ext4_evict_inode+0x88/0x5c0 evict+0xf8/0x2a0 dispose_list+0x50/0x80 prune_icache_sb+0x6c/0x90 super_cache_scan+0x190/0x210 shrink_slab.part.15+0x22c/0x4c0 shrink_zone+0x288/0x3c0 do_try_to_free_pages+0x1dc/0x590 try_to_free_pages+0xdc/0x260 __alloc_pages_nodemask+0x72c/0xc90 alloc_pages_current+0xb4/0x1a0 page_table_alloc+0xc0/0x170 __pte_alloc+0x58/0x1f0 copy_page_range+0x4ec/0x950 copy_process.isra.5+0x15a0/0x1870 _do_fork+0xa8/0x4b0 ppc_clone+0x8/0xc In the meanwhile, all processes exiting/forking are blocked almost stalling the system. This patch moves the threadgroup_change_begin from before cgroup_fork() to just before cgroup_canfork(). There is no nee to worry about threadgroup changes till the task is actually added to the threadgroup. This avoids having to call reclaim with cgroup_threadgroup_rwsem held. tj: Subject and description edits. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Zefan Li <lizefan@huawei.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Tejun Heo <tj@kernel.org> [jstultz: Cherry-picked from: git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git 568ac888215c7f] Change-Id: Ie8ece84fb613cf6a7b08cea1468473a8df2b9661 Signed-off-by: John Stultz <john.stultz@linaro.org>
| | * | | | | | | | RFC: FROMLIST: cgroup: avoid synchronize_sched() in __cgroup_procs_write()Peter Zijlstra2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current percpu-rwsem read side is entirely free of serializing insns at the cost of having a synchronize_sched() in the write path. The latency of the synchronize_sched() is too high for cgroups. The commit 1ed1328792ff talks about the write path being a fairly cold path but this is not the case for Android which moves task to the foreground cgroup and back around binder IPC calls from foreground processes to background processes, so it is significantly hotter than human initiated operations. Switch cgroup_threadgroup_rwsem into the slow mode for now to avoid the problem, hopefully it should not be that slow after another commit 80127a39681b ("locking/percpu-rwsem: Optimize readers and reduce global impact"). We could just add rcu_sync_enter() into cgroup_init() but we do not want another synchronize_sched() at boot time, so this patch adds the new helper which doesn't block but currently can only be called before the first use. Cc: Tejun Heo <tj@kernel.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Reported-by: John Stultz <john.stultz@linaro.org> Reported-by: Dmitry Shmidt <dimitrysh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> [jstultz: backported to 4.4] Change-Id: I34aa9c394d3052779b56976693e96d861bd255f2 Mailing-list-URL: https://lkml.org/lkml/2016/8/11/557 Signed-off-by: John Stultz <john.stultz@linaro.org>
| | * | | | | | | | RFC: FROMLIST: locking/percpu-rwsem: Optimize readers and reduce global impactPeter Zijlstra2016-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the percpu-rwsem switches to (global) atomic ops while a writer is waiting; which could be quite a while and slows down releasing the readers. This patch cures this problem by ordering the reader-state vs reader-count (see the comments in __percpu_down_read() and percpu_down_write()). This changes a global atomic op into a full memory barrier, which doesn't have the global cacheline contention. This also enables using the percpu-rwsem with rcu_sync disabled in order to bias the implementation differently, reducing the writer latency by adding some cost to readers. Mailing-list-URL: https://lkml.org/lkml/2016/8/9/181 Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [jstultz: Backported to 4.4] Change-Id: I8ea04b4dca2ec36f1c2469eccafde1423490572f Signed-off-by: John Stultz <john.stultz@linaro.org>
| | * | | | | | | | Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidAlex Shi2016-08-30
| | |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/arm/Kconfig
| | | * | | | | | | x86: remove more uaccess_32.h complexityLinus Torvalds2016-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm looking at trying to possibly merge the 32-bit and 64-bit versions of the x86 uaccess.h implementation, but first this needs to be cleaned up. For example, the 32-bit version of "__copy_from_user_inatomic()" is mostly the special cases for the constant size, and it's actually almost never relevant. Most users aren't actually using a constant size anyway, and the few cases that do small constant copies are better off just using __get_user() instead. So get rid of the unnecessary complexity. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit bd28b14591b98f696bc9f94c5ba2e598ca487dfd) Signed-off-by: Alex Shi <alex.shi@linaro.org>
| | * | | | | | | | Revert "panic: Add board ID to panic output"Amit Pundir2016-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 4e09c510185cb4db2277ce81cce81b7aa06bea45. I checked for the usage of this debug helper in AOSP common kernels as well as vendor kernels (e.g exynos, msm, mediatek, omap, tegra, x86, x86_64) hosted at https://android.googlesource.com/kernel/ and I found out that other than few fairly obsolete Omap trees (for tuna & Glass) and Exynos tree (for Manta), there is no active user of this debug helper. So we can safely remove this helper code. Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
| | * | | | | | | | cpuset: Add allow_attach hook for cpusets on android.Riley Andrews2016-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides a allow_attach hook for cpusets, which resolves lots of the following logcat noise. W SchedPolicy: add_tid_to_cgroup failed to write '2816' (Permission denied); fd=29 W ActivityManager: Failed setting process group of 2816 to 0 W System.err: java.lang.IllegalArgumentException W System.err: at android.os.Process.setProcessGroup(Native Method) W System.err: at com.android.server.am.ActivityManagerService.applyOomAdjLocked(ActivityManagerService.java:18763) W System.err: at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:19028) W System.err: at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:19106) W System.err: at com.android.server.am.ActiveServices.serviceDoneExecutingLocked(ActiveServices.java:2015) W System.err: at com.android.server.am.ActiveServices.publishServiceLocked(ActiveServices.java:905) W System.err: at com.android.server.am.ActivityManagerService.publishService(ActivityManagerService.java:16065) W System.err: at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:1007) W System.err: at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2493) W System.err: at android.os.Binder.execTransact(Binder.java:453) Change-Id: Ic1b61b2bbb7ce74c9e9422b5e22ee9078251de21 [Ported to 4.4, added commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
| | * | | | | | | | Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidAlex Shi2016-08-11
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| | | * | | | | | | Merge tag 'v4.4.17' into linux-linaro-lsk-v4.4Alex Shi2016-08-11
| | | |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the 4.4.17 stable release
| | | | * | | | | | posix_cpu_timer: Exit early when process has been reapedAlexey Dobriyan2016-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2c13ce8f6b2f6fd9ba2f9261b1939fc0f62d1307 upstream. Variable "now" seems to be genuinely used unintialized if branch if (CPUCLOCK_PERTHREAD(timer->it_clock)) { is not taken and branch if (unlikely(sighand == NULL)) { is taken. In this case the process has been reaped and the timer is marked as disarmed anyway. So none of the postprocessing of the sample is required. Return right away. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Link: http://lkml.kernel.org/r/20160707223911.GA26483@p183.telecom.by Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | | | * | | | | | sched/fair: Fix effective_load() to consistently use smoothed loadPeter Zijlstra2016-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7dd4912594daf769a46744848b05bd5bc6d62469 upstream. Starting with the following commit: fde7d22e01aa ("sched/fair: Fix overly small weight for interactive group entities") calc_tg_weight() doesn't compute the right value as expected by effective_load(). The difference is in the 'correction' term. In order to ensure \Sum rw_j >= rw_i we cannot use tg->load_avg directly, since that might be lagging a correction on the current cfs_rq->avg.load_avg value. Therefore we use tg->load_avg - cfs_rq->tg_load_avg_contrib + cfs_rq->avg.load_avg. Now, per the referenced commit, calc_tg_weight() doesn't use cfs_rq->avg.load_avg, as is later used in @w, but uses cfs_rq->load.weight instead. So stop using calc_tg_weight() and do it explicitly. The effects of this bug are wake_affine() making randomly poor choices in cgroup-intense workloads. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: fde7d22e01aa ("sched/fair: Fix overly small weight for interactive group entities") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | | | * | | | | | cgroup: set css->id to -1 during initTejun Heo2016-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8fa3b8d689a54d6d04ff7803c724fb7aca6ce98e upstream. If percpu_ref initialization fails during css_create(), the free path can end up trying to free css->id of zero. As ID 0 is unused, it doesn't cause a critical breakage but it does trigger a warning message. Fix it by setting css->id to -1 from init_and_link_css(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Wenwei Tao <ww.tao0320@gmail.com> Fixes: 01e586598b22 ("cgroup: release css->id after css_free") Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | | | * | | | | | kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while ↵Andrey Ryabinin2016-08-10
| | | | | |_|_|_|/ | | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | processing sysrq-w commit 57675cb976eff977aefb428e68e4e0236d48a9ff upstream. Lengthy output of sysrq-w may take a lot of time on slow serial console. Currently we reset NMI-watchdog on the current CPU to avoid spurious lockup messages. Sometimes this doesn't work since softlockup watchdog might trigger on another CPU which is waiting for an IPI to proceed. We reset softlockup watchdogs on all CPUs, but we do this only after listing all tasks, and this may be too late on a busy system. So, reset watchdogs CPUs earlier, in for_each_process_thread() loop. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1465474805-14641-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | / | | | | Revert "sched/cputime: Fix steal time accounting vs. CPU hotplug"Syed Rameez Mustafa2016-12-14
|/ / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 2a8225ef46968444fb1c4c632ec28e4cc2be633f ("sched/cputime: Fix steal time accounting vs. CPU hotplug"). The commit introduces a bug in scheduler book-keeping whereby if a CPU is hotplugged out for a small duration of time, subsequent time spent executing tasks gets mis-attributed to interrupts. This in turn results in unfair scheduling whereby a task can keep executing for a very long time without any update to it's vruntime. This revert has no side effects for msm based systems. Change-Id: Ibb506824c4223551bceb449594ac99f9dfd8064b Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
* | | | | | | | Merge "sched: Ensure proper task migration when a CPU is isolated"Linux Build Service Account2016-12-10
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| * | | | | | | | sched: Ensure proper task migration when a CPU is isolatedSyed Rameez Mustafa2016-12-09
| | |_|_|/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | migrate_tasks() migrates all tasks of a CPU by using pick_next_task(). This works in the hotplug case as we force migrate every single task allowing pick_next_task() to return a new task on every loop iteration. In the case of isolation, however, task migration is not guaranteed which causes pick_next_task() to keep returning the same task over and over again until we terminate the loop without having migrated all the tasks that were supposed to migrated. Fix the above problem by temporarily dequeuing tasks that are pinned and marking them with TASK_ON_RQ_MIGRATING. This not only allows pick_next_task() to properly walk the runqueue but also prevents any migrations or changes in affinity for the dequeued tasks. Once we are done with migrating all possible tasks, we re-enqueue all the dequeued tasks. While at it, ensure consistent ordering between task de-activation and setting the TASK_ON_RQ_MIGRATING flag across all scheduling classes. Change-Id: Id06151a8e34edab49ac76b4bffd50c132f0b792f Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
* | | | | | | | sched/core: Fix race condition in clearing hmp requestOlav Haugan2016-12-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race condition between clearing an HMP request for active migration and the actual active migration. Active migration can he half-way through doing the migration when the HMP request can be cleared by another core. Move clearing of HMP request to the stopper thread to avoid this. Change-Id: I6d73b8f246ae3754ab60984af198333fd284ae16 Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
* | | | | | | | sched/core: Prevent (user) space tasks from affining to isolated cpusOlav Haugan2016-12-09
|/ / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't want user space tasks to run on isolated cpus. If the affinity mask that the user space task is trying to set only includes online cpus that are isolated return error. Also ensure that tasks do not get stuck on isolated cores. We are not properly updating the mask that we check against the current CPU so we might end up thinking we can run on the current CPU. Fix this. Change-Id: I078d01e63860d1fc60fc96eb0c739c0f680ae983 Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
* | | | | | | Merge "sched: pre-allocate colocation groups"Linux Build Service Account2016-12-01
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| * | | | | | | sched: pre-allocate colocation groupsJoonwoo Park2016-12-01
| | |_|_|/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At present, sched_set_group_id() dynamically allocates structure for colocation group to assign the given task to the group. However this can cause deadlock as memory allocator can wakeup a task which also tries to acquire related_thread_group_lock. Avoid such deadlock by pre-allocating colocation structures. This limits maximum colocation groups to static number but it's fine as it's never expected to be a lot. Change-Id: Ifc32ab4ead63c382ae390358ed86f7cc5b6eb2dc Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
* | | | | | | Merge "sched: Disable interrupts while holding related_thread_group_lock"Linux Build Service Account2016-11-29
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| * | | | | | | sched: Disable interrupts while holding related_thread_group_lockPavankumar Kondeti2016-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a potential deadlock condition if interrupts are enabled while holding the related_thread_group_lock. Prevent this. ---------------- -------------------- CPU 0 CPU 1 --------------- -------------------- check_for_migration() cgroup_file_write(p) check_for_freq_change() cgroup_attach_task(p) send_notification() schedtune_attach(p) read_lock(&related_thread_group_lock) sched_set_group_id(p) raw_spin_lock_irqsave( &p->pi_lock, flags) write_lock_irqsave( &related_thread_group_lock) waiting on CPU#0 raw_spin_lock_irqsave(&rq->lock, flags) raw_spin_unlock_irqrestore(&rq->lock, flags) --> interrupt() ----> ttwu(p) -------> waiting for p's pi_lock on CPU#1 Change-Id: I6f0f8f742d6e1b3ff735dcbeabd54ef101329cdf Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
* | | | | | | | Merge "sched/core: Do not free task while holding rq lock"Linux Build Service Account2016-11-28
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| * | | | | | | | sched/core: Do not free task while holding rq lockOlav Haugan2016-11-28
| |/ / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clearing the hmp request can cause a task to be freed. When a task is freed the free call might wake up a kworker which will cause a spinlock lockup (rq lock). Fix this by avoiding calling put_task_struct when holding the rq lock. In addition move call to clear_hmp_request out of stopper thread context since it is not necessary to do this on the cpu being isolated. Change-Id: Ie577db4701a88849560df385869ff7cf73695a05 Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
* | | | | | | | Merge "qos: Register irq notify after adding the qos request"Linux Build Service Account2016-11-28
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| * | | | | | | qos: Register irq notify after adding the qos requestAnil Kumar Mamidala2016-11-27
| |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before adding the irq affinity based qos request to the list, if the affinity of the interrupt changes it will trigger notify call. This notifier call will try to update the qos request. Accessing the qos request which is not yet added to the list leads to a NULL pointer exception. Avoid this race by registering the notifier after adding the qos request. Change-Id: I99869cc233573b5db10e4f3224d65c29511050ea Signed-off-by: Anil Kumar Mamidala <amami@codeaurora.org>
* | | | | | | Merge "sched: Ensure proper synch between isolation, hotplug, and suspend"Linux Build Service Account2016-11-27
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| * | | | | | sched: Ensure proper synch between isolation, hotplug, and suspendOlav Haugan2016-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Isolation code needs to be synchronized with both hotplug and suspend. Ensure this by taking the lock that is taken by both paths and ensure hotplug notifiers are processed for suspend/resume. Change-Id: I663588cfd2f9e3972b9adc1a10887ef36cd70c57 Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
* | | | | | | Merge "qos: wake up cores based on the qos updated cpu mask"Linux Build Service Account2016-11-26
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| * | | | | | | qos: wake up cores based on the qos updated cpu maskAnil Kumar Mamidala2016-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the qos value is increased only for a subset of cpu's aggregated qos for those cpu's is still the previous value. This is because the qos request list is maintained per request and not per cpu. In this case as there is no change in aggregated qos value, these cpu's are not wokenup to take the new qos value into effect. So wakeup cpu's even if the aggregated qos value does not change but the cpumask changes. Change-Id: If5a4a100108e85e04beb77e5249bd6c452672edf Signed-off-by: Anil Kumar Mamidala <amami@codeaurora.org>
* | | | | | | | Merge "audit: fix a double fetch in audit_log_single_execve_arg()"Linux Build Service Account2016-11-25
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| * | | | | | | audit: fix a double fetch in audit_log_single_execve_arg()Paul Moore2016-11-23
| |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a double fetch problem in audit_log_single_execve_arg() where we first check the execve(2) argumnets for any "bad" characters which would require hex encoding and then re-fetch the arguments for logging in the audit record[1]. Of course this leaves a window of opportunity for an unsavory application to munge with the data. This patch reworks things by only fetching the argument data once[2] into a buffer where it is scanned and logged into the audit records(s). In addition to fixing the double fetch, this patch improves on the original code in a few other ways: better handling of large arguments which require encoding, stricter record length checking, and some performance improvements (completely unverified, but we got rid of some strlen() calls, that's got to be a good thing). As part of the development of this patch, I've also created a basic regression test for the audit-testsuite, the test can be tracked on GitHub at the following link: * https://github.com/linux-audit/audit-testsuite/issues/25 [1] If you pay careful attention, there is actually a triple fetch problem due to a strnlen_user() call at the top of the function. [2] This is a tiny white lie, we do make a call to strnlen_user() prior to fetching the argument data. I don't like it, but due to the way the audit record is structured we really have no choice unless we copy the entire argument at once (which would require a rather wasteful allocation). The good news is that with this patch the kernel no longer relies on this strnlen_user() value for anything beyond recording it in the log, we also update it with a trustworthy value whenever possible. Reported-by: Pengfei Wang <wpengfeinudt@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com> Change-Id: Ie9848961d236739df5014474f2c2a781af9fb811 Git-repo: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git Git-commit: 43761473c254b45883a64441dd0bc85a42f3645c Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
* / / / / / / cgroup: prefer %pK to %pNick Desaulniers2016-11-18
|/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prevents leaking kernel pointers when using kptr_restrict. Bug: 30149174 Change-Id: I0fa3cd8d4a0d9ea76d085bba6020f1eda073c09b Git-repo: https://android.googlesource.com/kernel/msm.git Git-commit: 505e48f32f1321ed7cf80d49dd5f31b16da445a8 Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
* | | | | | sched/hmp: Enhance co-location and scheduler boost featuresSyed Rameez Mustafa2016-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent introduction of the schedtune cgroup controller has provided the scheduler with added flexibility in terms of some of it's placement features. In particular each cgroup under the schedtune controller can now specify: 1) Whether it needs co-location along with other cgroups 2) Whether it is eligible for scheduler boost (sched_boost_enabled) 3) Whether the kernel can override the boost eligibility when necessary (sched_boost_no_override) The scheduler now creates a reserved co-location group at boot. This group is used to co-locate all tasks that form part of any one of the cgroups that have co-location enabled. This reserved group can neither be destroyed nor reused for other purposes. Furthermore, cgroups are only allowed to indicate their co-location preference once at boot. Further updates are disallowed. Since we are now creating co-location groups for an extended period of time, there are a few other factors to consider when determining the preferred cluster for the group. We first exclude any tasks in the group that have not been observed to be running for a significant amount of time. Secondly we introduce the notion of group up and down migrate tunables to allow different migration policies than individual tasks. Lastly we break co-location if a single task in a group exceeds up-migrate but the total load of the group does not exceed group up-migrate. In terms of sched_boost, the scheduler now supports multiple types of boost. These are: 1) FULL_THROTTLE : Force up-migrate tasks belonging any cgroup that has the sched_boost_enabled flag turned on. Little CPUs will only be used when big CPUs can no longer accommodate tasks. Also up-migrate all RT tasks. 2) CONSERVATIVE : Override the sched_boost_enabled flag for all cgroups except those that have the sched_boost_no_override flag set. Force up-migrate all tasks belonging to only those cgroups that still remain eligible for boost. RT tasks do not get force up migrated. 3) RESTRAINED : Start frequency aggregation for co-located tasks. This type of boost does not force up-migrate any task. Finally the boost API removes ref-counting. This means that there can only be a single entity using boost at any given time. If multiple entities are managing boost, they are required to be well behaved so that they don't interfere with one another. Even for a single client, it is not possible to switch directly from one boost type to another. Boost must be first turned off before switching over to a new type. Change-Id: I8d224a70cbef162f27078b62b73acaa22670861d Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>