mirror of
https://github.com/ukui/kernel.git
synced 2026-03-09 10:07:04 -07:00
bc4f2199ca3107809df96cf72f618b9559b00a21
1782 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Jann Horn
|
cb361d8cde |
sched/fair: Use RCU accessors consistently for ->numa_group
The old code used RCU annotations and accessors inconsistently for
->numa_group, which can lead to use-after-frees and NULL dereferences.
Let all accesses to ->numa_group use proper RCU helpers to prevent such
issues.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes:
|
||
 Linus Torvalds
|
c236b6dd48 |
Merge tag 'keys-request-20190626' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull request_key improvements from David Howells:
"These are all request_key()-related, including a fix and some improvements:
- Fix the lack of a Link permission check on a key found by
request_key(), thereby enabling request_key() to link keys that
don't grant this permission to the target keyring (which must still
grant Write permission).
Note that the key must be in the caller's keyrings already to be
found.
- Invalidate used request_key authentication keys rather than
revoking them, so that they get cleaned up immediately rather than
hanging around till the expiry time is passed.
- Move the RCU locks outwards from the keyring search functions so
that a request_key_rcu() can be provided. This can be called in RCU
mode, so it can't sleep and can't upcall - but it can be called
from LOOKUP_RCU pathwalk mode.
- Cache the latest positive result of request_key*() temporarily in
task_struct so that filesystems that make a lot of request_key()
calls during pathwalk can take advantage of it to avoid having to
redo the searching. This requires CONFIG_KEYS_REQUEST_CACHE=y.
It is assumed that the key just found is likely to be used multiple
times in each step in an RCU pathwalk, and is likely to be reused
for the next step too.
Note that the cleanup of the cache is done on TIF_NOTIFY_RESUME,
just before userspace resumes, and on exit"
* tag 'keys-request-20190626' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Kill off request_key_async{,_with_auxdata}
keys: Cache result of request_key*() temporarily in task_struct
keys: Provide request_key_rcu()
keys: Move the RCU locks outwards from the keyring search functions
keys: Invalidate used request_key authentication keys
keys: Fix request_key() lack of Link perm check on found key
|
||
|
Linus Torvalds
|
dad1c12ed8 |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: - Remove the unused per rq load array and all its infrastructure, by Dietmar Eggemann. - Add utilization clamping support by Patrick Bellasi. This is a refinement of the energy aware scheduling framework with support for boosting of interactive and capping of background workloads: to make sure critical GUI threads get maximum frequency ASAP, and to make sure background processing doesn't unnecessarily move to cpufreq governor to higher frequencies and less energy efficient CPU modes. - Add the bare minimum of tracepoints required for LISA EAS regression testing, by Qais Yousef - which allows automated testing of various power management features, including energy aware scheduling. - Restructure the former tsk_nr_cpus_allowed() facility that the -rt kernel used to modify the scheduler's CPU affinity logic such as migrate_disable() - introduce the task->cpus_ptr value instead of taking the address of &task->cpus_allowed directly - by Sebastian Andrzej Siewior. - Misc optimizations, fixes, cleanups and small enhancements - see the Git log for details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) sched/uclamp: Add uclamp support to energy_compute() sched/uclamp: Add uclamp_util_with() sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks sched/uclamp: Set default clamps for RT tasks sched/uclamp: Reset uclamp values on RESET_ON_FORK sched/uclamp: Extend sched_setattr() to support utilization clamping sched/core: Allow sched_setattr() to use the current policy sched/uclamp: Add system default clamps sched/uclamp: Enforce last task's UCLAMP_MAX sched/uclamp: Add bucket local max tracking sched/uclamp: Add CPU's clamp buckets refcounting sched/fair: Rename weighted_cpuload() to cpu_runnable_load() sched/debug: Export the newly added tracepoints sched/debug: Add sched_overutilized tracepoint sched/debug: Add new tracepoint to track PELT at se level sched/debug: Add new tracepoints to track PELT at rq level sched/debug: Add a new sched_trace_*() helper functions sched/autogroup: Make autogroup_path() always available sched/wait: Deduplicate code with do-while sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity() ... |
||
|
Linus Torvalds
|
46f1ec23a4 |
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
"The changes in this cycle are:
- RCU flavor consolidation cleanups and optmizations
- Documentation updates
- Miscellaneous fixes
- SRCU updates
- RCU-sync flavor consolidation
- Torture-test updates
- Linux-kernel memory-consistency-model updates, most notably the
addition of plain C-language accesses"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
tools/memory-model: Improve data-race detection
tools/memory-model: Change definition of rcu-fence
tools/memory-model: Expand definition of barrier
tools/memory-model: Do not use "herd" to refer to "herd7"
tools/memory-model: Fix comment in MP+poonceonces.litmus
Documentation: atomic_t.txt: Explain ordering provided by smp_mb__{before,after}_atomic()
rcu: Don't return a value from rcu_assign_pointer()
rcu: Force inlining of rcu_read_lock()
rcu: Fix irritating whitespace error in rcu_assign_pointer()
rcu: Upgrade sync_exp_work_done() to smp_mb()
rcutorture: Upper case solves the case of the vanishing NULL pointer
torture: Suppress propagating trace_printk() warning
rcutorture: Dump trace buffer for callback pipe drain failures
torture: Add --trust-make to suppress "make clean"
torture: Make --cpus override idleness calculations
torture: Run kernel build in source directory
torture: Add function graph-tracing cheat sheet
torture: Capture qemu output
rcutorture: Tweak kvm options
rcutorture: Add trivial RCU implementation
...
|
||
 Patrick Bellasi
|
a509a7cd79 |
sched/uclamp: Extend sched_setattr() to support utilization clamping
The SCHED_DEADLINE scheduling class provides an advanced and formal model to define tasks requirements that can translate into proper decisions for both task placements and frequencies selections. Other classes have a more simplified model based on the POSIX concept of priorities. Such a simple priority based model however does not allow to exploit most advanced features of the Linux scheduler like, for example, driving frequencies selection via the schedutil cpufreq governor. However, also for non SCHED_DEADLINE tasks, it's still interesting to define tasks properties to support scheduler decisions. Utilization clamping exposes to user-space a new set of per-task attributes the scheduler can use as hints about the expected/required utilization for a task. This allows to implement a "proactive" per-task frequency control policy, a more advanced policy than the current one based just on "passive" measured task utilization. For example, it's possible to boost interactive tasks (e.g. to get better performance) or cap background tasks (e.g. to be more energy/thermal efficient). Introduce a new API to set utilization clamping values for a specified task by extending sched_setattr(), a syscall which already allows to define task specific properties for different scheduling classes. A new pair of attributes allows to specify a minimum and maximum utilization the scheduler can consider for a task. Do that by validating the required clamp values before and then applying the required changes using _the_ same pattern already in use for __setscheduler(). This ensures that the task is re-enqueued with the new clamp values. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190621084217.8167-7-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Patrick Bellasi
|
e8f14172c6 |
sched/uclamp: Add system default clamps
Tasks without a user-defined clamp value are considered not clamped
and by default their utilization can have any value in the
[0..SCHED_CAPACITY_SCALE] range.
Tasks with a user-defined clamp value are allowed to request any value
in that range, and the required clamp is unconditionally enforced.
However, a "System Management Software" could be interested in limiting
the range of clamp values allowed for all tasks.
Add a privileged interface to define a system default configuration via:
/proc/sys/kernel/sched_uclamp_util_{min,max}
which works as an unconditional clamp range restriction for all tasks.
With the default configuration, the full SCHED_CAPACITY_SCALE range of
values is allowed for each clamp index. Otherwise, the task-specific
clamp is capped by the corresponding system default value.
Do that by tracking, for each task, the "effective" clamp value and
bucket the task has been refcounted in at enqueue time. This
allows to lazy aggregate "requested" and "system default" values at
enqueue time and simplifies refcounting updates at dequeue time.
The cached bucket ids are used to avoid (relatively) more expensive
integer divisions every time a task is enqueued.
An active flag is used to report when the "effective" value is valid and
thus the task is actually refcounted in the corresponding rq's bucket.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-5-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
Patrick Bellasi
|
69842cba9a |
sched/uclamp: Add CPU's clamp buckets refcounting
Utilization clamping allows to clamp the CPU's utilization within a
[util_min, util_max] range, depending on the set of RUNNABLE tasks on
that CPU. Each task references two "clamp buckets" defining its minimum
and maximum (util_{min,max}) utilization "clamp values". A CPU's clamp
bucket is active if there is at least one RUNNABLE tasks enqueued on
that CPU and refcounting that bucket.
When a task is {en,de}queued {on,from} a rq, the set of active clamp
buckets on that CPU can change. If the set of active clamp buckets
changes for a CPU a new "aggregated" clamp value is computed for that
CPU. This is because each clamp bucket enforces a different utilization
clamp value.
Clamp values are always MAX aggregated for both util_min and util_max.
This ensures that no task can affect the performance of other
co-scheduled tasks which are more boosted (i.e. with higher util_min
clamp) or less capped (i.e. with higher util_max clamp).
A task has:
task_struct::uclamp[clamp_id]::bucket_id
to track the "bucket index" of the CPU's clamp bucket it refcounts while
enqueued, for each clamp index (clamp_id).
A runqueue has:
rq::uclamp[clamp_id]::bucket[bucket_id].tasks
to track how many RUNNABLE tasks on that CPU refcount each
clamp bucket (bucket_id) of a clamp index (clamp_id).
It also has a:
rq::uclamp[clamp_id]::bucket[bucket_id].value
to track the clamp value of each clamp bucket (bucket_id) of a clamp
index (clamp_id).
The rq::uclamp::bucket[clamp_id][] array is scanned every time it's
needed to find a new MAX aggregated clamp value for a clamp_id. This
operation is required only when it's dequeued the last task of a clamp
bucket tracking the current MAX aggregated clamp value. In this case,
the CPU is either entering IDLE or going to schedule a less boosted or
more clamped task.
The expected number of different clamp values configured at build time
is small enough to fit the full unordered array into a single cache
line, for configurations of up to 7 buckets.
Add to struct rq the basic data structures required to refcount the
number of RUNNABLE tasks for each clamp bucket. Add also the max
aggregation required to update the rq's clamp value at each
enqueue/dequeue event.
Use a simple linear mapping of clamp values into clamp buckets.
Pre-compute and cache bucket_id to avoid integer divisions at
enqueue/dequeue time.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-2-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
 Qais Yousef
|
3c93a0c04d |
sched/debug: Add a new sched_trace_*() helper functions
The new functions allow modules to access internal data structures of unexported struct cfs_rq and struct rq to extract important information from the tracepoints to be introduced in later patches. While at it fix alphabetical order of struct declarations in sched.h Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavankumar Kondeti <pkondeti@codeaurora.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de> Link: https://lkml.kernel.org/r/20190604111459.2862-3-qais.yousef@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
 David Howells
|
7743c48e54 |
keys: Cache result of request_key*() temporarily in task_struct
If a filesystem uses keys to hold authentication tokens, then it needs a
token for each VFS operation that might perform an authentication check -
either by passing it to the server, or using to perform a check based on
authentication data cached locally.
For open files this isn't a problem, since the key should be cached in the
file struct since it represents the subject performing operations on that
file descriptor.
During pathwalk, however, there isn't anywhere to cache the key, except
perhaps in the nameidata struct - but that isn't exposed to the
filesystems. Further, a pathwalk can incur a lot of operations, calling
one or more of the following, for instance:
->lookup()
->permission()
->d_revalidate()
->d_automount()
->get_acl()
->getxattr()
on each dentry/inode it encounters - and each one may need to call
request_key(). And then, at the end of pathwalk, it will call the actual
operation:
->mkdir()
->mknod()
->getattr()
->open()
...
which may need to go and get the token again.
However, it is very likely that all of the operations on a single
dentry/inode - and quite possibly a sequence of them - will all want to use
the same authentication token, which suggests that caching it would be a
good idea.
To this end:
(1) Make it so that a positive result of request_key() and co. that didn't
require upcalling to userspace is cached temporarily in task_struct.
(2) The cache is 1 deep, so a new result displaces the old one.
(3) The key is released by exit and by notify-resume.
(4) The cache is cleared in a newly forked process.
Signed-off-by: David Howells <dhowells@redhat.com>
|
||
 Heiko Carstens
|
4ecf0a43e7 |
processor: get rid of cpu_relax_yield
stop_machine is the only user left of cpu_relax_yield. Given that it now has special semantics which are tied to stop_machine introduce a weak stop_machine_yield function which architectures can override, and get rid of the generic cpu_relax_yield implementation. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> |
||
 Martin Schwidefsky
|
38f2c691a4 |
s390: improve wait logic of stop_machine
The stop_machine loop to advance the state machine and to wait for all affected CPUs to check-in calls cpu_relax_yield in a tight loop until the last missing CPUs acknowledged the state transition. On a virtual system where not all logical CPUs are backed by real CPUs all the time it can take a while for all CPUs to check-in. With the current definition of cpu_relax_yield a diagnose 0x44 is done which tells the hypervisor to schedule *some* other CPU. That can be any CPU and not necessarily one of the CPUs that need to run in order to advance the state machine. This can lead to a pretty bad diagnose 0x44 storm until the last missing CPU finally checked-in. Replace the undirected cpu_relax_yield based on diagnose 0x44 with a directed yield. Each CPU in the wait loop will pick up the next CPU in the cpumask of stop_machine. The diagnose 0x9c is used to tell the hypervisor to run this next CPU instead of the current one. If there is only a limited number of real CPUs backing the virtual CPUs we end up with the real CPUs passed around in a round-robin fashion. [heiko.carstens@de.ibm.com]: Use cpumask_next_wrap as suggested by Peter Zijlstra. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> |
||
 Sebastian Andrzej Siewior
|
3bd3706251 |
sched/core: Provide a pointer to the valid CPU mask
In commit:
|
||
 Paul E. McKenney
|
23634ebc1d |
rcu: Check for wakeup-safe conditions in rcu_read_unlock_special()
When RCU core processing is offloaded from RCU_SOFTIRQ to the rcuc kthreads, a full and unconditional wakeup is required to initiate RCU core processing. In contrast, when RCU core processing is carried out by RCU_SOFTIRQ, a raise_softirq() suffices. Of course, there are situations where raise_softirq() does a full wakeup, but these do not occur with normal usage of rcu_read_unlock(). The reason that full wakeups can be problematic is that the scheduler sometimes invokes rcu_read_unlock() with its pi or rq locks held, which can of course result in deadlock in CONFIG_PREEMPT=y kernels when rcu_read_unlock() invokes the scheduler. Scheduler invocations can happen in the following situations: (1) The just-ended reader has been subjected to RCU priority boosting, in which case rcu_read_unlock() must deboost, (2) Interrupts were disabled across the call to rcu_read_unlock(), so the quiescent state must be deferred, requiring a wakeup of the rcuc kthread corresponding to the current CPU. Now, the scheduler may hold one of its locks across rcu_read_unlock() only if preemption has been disabled across the entire RCU read-side critical section, which in the days prior to RCU flavor consolidation meant that rcu_read_unlock() never needed to do wakeups. However, this is no longer the case for any but the first rcu_read_unlock() following a condition (e.g., preempted RCU reader) requiring special rcu_read_unlock() attention. For example, an RCU read-side critical section might be preempted, but preemption might be disabled across the rcu_read_unlock(). The rcu_read_unlock() must defer the quiescent state, and therefore leaves the task queued on its leaf rcu_node structure. If a scheduler interrupt occurs, the scheduler might well invoke rcu_read_unlock() with one of its locks held. However, the preempted task is still queued, so rcu_read_unlock() will attempt to defer the quiescent state once more. When RCU core processing is carried out by RCU_SOFTIRQ, this works just fine: The raise_softirq() function simply sets a bit in a per-CPU mask and the RCU core processing will be undertaken upon return from interrupt. Not so when RCU core processing is carried out by the rcuc kthread: In this case, the required wakeup can result in deadlock. The initial solution to this problem was to use set_tsk_need_resched() and set_preempt_need_resched() to force a future context switch, which allows rcu_preempt_note_context_switch() to report the deferred quiescent state to RCU's core processing. Unfortunately for expedited grace periods, there can be a significant delay between the call for a context switch and the actual context switch. This commit therefore introduces a ->deferred_qs flag to the task_struct structure's rcu_special structure. This flag is initially false, and is set to true by the first call to rcu_read_unlock() requiring special attention, then finally reset back to false when the quiescent state is finally reported. Then rcu_read_unlock() attempts full wakeups only when ->deferred_qs is false, that is, on the first rcu_read_unlock() requiring special attention. Note that a chain of RCU readers linked by some other sort of reader may find that a later rcu_read_unlock() is once again able to do a full wakeup, courtesy of an intervening preemption: rcu_read_lock(); /* preempted */ local_irq_disable(); rcu_read_unlock(); /* Can do full wakeup, sets ->deferred_qs. */ rcu_read_lock(); local_irq_enable(); preempt_disable() rcu_read_unlock(); /* Cannot do full wakeup, ->deferred_qs set. */ rcu_read_lock(); preempt_enable(); /* preempted, >deferred_qs reset. */ local_irq_disable(); rcu_read_unlock(); /* Can again do full wakeup, sets ->deferred_qs. */ Such linked RCU readers do not yet seem to appear in the Linux kernel, and it is probably best if they don't. However, RCU needs to handle them, and some variations on this theme could make even raise_softirq() unsafe due to the possibility of its doing a full wakeup. This commit therefore also avoids invoking raise_softirq() when the ->deferred_qs set flag is set. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
||
 Suren Baghdasaryan
|
8af0c18af1 |
include/: refactor headers to allow kthread.h inclusion in psi_types.h
kthread.h can't be included in psi_types.h because it creates a circular inclusion with kthread.h eventually including psi_types.h and complaining on kthread structures not being defined because they are defined further in the kthread.h. Resolve this by removing psi_types.h inclusion from the headers included from kthread.h. Link: http://lkml.kernel.org/r/20190319235619.260832-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
abde77eb5c |
Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "This includes Roman's cgroup2 freezer implementation. It's a separate machanism from cgroup1 freezer. Instead of blocking user tasks in arbitrary uninterruptible sleeps, the new implementation extends jobctl stop - frozen tasks are trapped in jobctl stop until thawed and can be killed and ptraced. Lots of thanks to Oleg for sheperding the effort. Other than that, there are a few trivial changes" * 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: never call do_group_exit() with task->frozen bit set kernel: cgroup: fix misuse of %x cgroup: get rid of cgroup_freezer_frozen_exit() cgroup: prevent spurious transition into non-frozen state cgroup: Remove unused cgrp variable cgroup: document cgroup v2 freezer interface cgroup: add tracing points for cgroup v2 freezer cgroup: make TRACE_CGROUP_PATH irq-safe kselftests: cgroup: add freezer controller self-tests kselftests: cgroup: don't fail on cg_kill_all() error in cg_destroy() cgroup: cgroup v2 freezer cgroup: protect cgroup->nr_(dying_)descendants by css_set_lock cgroup: implement __cgroup_task_count() helper cgroup: rename freezer.c into legacy_freezer.c cgroup: remove extra cgroup_migrate_finish() call |
||
 Roman Gushchin
|
76f969e894 |
cgroup: cgroup v2 freezer
Cgroup v1 implements the freezer controller, which provides an ability
to stop the workload in a cgroup and temporarily free up some
resources (cpu, io, network bandwidth and, potentially, memory)
for some other tasks. Cgroup v2 lacks this functionality.
This patch implements freezer for cgroup v2.
Cgroup v2 freezer tries to put tasks into a state similar to jobctl
stop. This means that tasks can be killed, ptraced (using
PTRACE_SEIZE*), and interrupted. It is possible to attach to
a frozen task, get some information (e.g. read registers) and detach.
It's also possible to migrate a frozen tasks to another cgroup.
This differs cgroup v2 freezer from cgroup v1 freezer, which mostly
tried to imitate the system-wide freezer. However uninterruptible
sleep is fine when all tasks are going to be frozen (hibernation case),
it's not the acceptable state for some subset of the system.
Cgroup v2 freezer is not supporting freezing kthreads.
If a non-root cgroup contains kthread, the cgroup still can be frozen,
but the kthread will remain running, the cgroup will be shown
as non-frozen, and the notification will not be delivered.
* PTRACE_ATTACH is not working because non-fatal signal delivery
is blocked in frozen state.
There are some interface differences between cgroup v1 and cgroup v2
freezer too, which are required to conform the cgroup v2 interface
design principles:
1) There is no separate controller, which has to be turned on:
the functionality is always available and is represented by
cgroup.freeze and cgroup.events cgroup control files.
2) The desired state is defined by the cgroup.freeze control file.
Any hierarchical configuration is allowed.
3) The interface is asynchronous. The actual state is available
using cgroup.events control file ("frozen" field). There are no
dedicated transitional states.
4) It's allowed to make any changes with the cgroup hierarchy
(create new cgroups, remove old cgroups, move tasks between cgroups)
no matter if some cgroups are frozen.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
No-objection-from-me-by: Oleg Nesterov <oleg@redhat.com>
Cc: kernel-team@fb.com
|
||
 Mathieu Desnoyers
|
83b0b15bcb |
rseq: Remove superfluous rseq_len from task_struct
The rseq system call, when invoked with flags of "0" or "RSEQ_FLAG_UNREGISTER" values, expects the rseq_len parameter to be equal to sizeof(struct rseq), which is fixed-size and fixed-layout, specified in uapi linux/rseq.h. Expecting a fixed size for rseq_len is a design choice that ensures multiple libraries and application defining __rseq_abi in the same process agree on its exact size. Considering that this size is and will always be the same value, there is no point in saving this value within task_struct rseq_len. Remove this field from task_struct. No change in functionality intended. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ben Maurer <bmaurer@fb.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Lameter <cl@linux.com> Cc: Dave Watson <davejwatson@fb.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/20190305194755.2602-3-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Linus Torvalds
|
be37f21a08 |
Merge tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore: "A lucky 13 audit patches for v5.1. Despite the rather large diffstat, most of the changes are from two bug fix patches that move code from one Kconfig option to another. Beyond that bit of churn, the remaining changes are largely cleanups and bug-fixes as we slowly march towards container auditing. It isn't all boring though, we do have a couple of new things: file capabilities v3 support, and expanded support for filtering on filesystems to solve problems with remote filesystems. All changes pass the audit-testsuite. Please merge for v5.1" * tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: mark expected switch fall-through audit: hide auditsc_get_stamp and audit_serial prototypes audit: join tty records to their syscall audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL audit: remove unused actx param from audit_rule_match audit: ignore fcaps on umount audit: clean up AUDITSYSCALL prototypes and stubs audit: more filter PATH records keyed on filesystem magic audit: add support for fcaps v3 audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDIT audit: add syscall information to CONFIG_CHANGE records audit: hand taken context to audit_kill_trees for syscall logging audit: give a clue what CONFIG_CHANGE op was involved |
||
|
Linus Torvalds
|
8dcd175bc3 |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton: - a few misc things - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (159 commits) tools/testing/selftests/proc/proc-self-syscall.c: remove duplicate include proc: more robust bulk read test proc: test /proc/*/maps, smaps, smaps_rollup, statm proc: use seq_puts() everywhere proc: read kernel cpu stat pointer once proc: remove unused argument in proc_pid_lookup() fs/proc/thread_self.c: code cleanup for proc_setup_thread_self() fs/proc/self.c: code cleanup for proc_setup_self() proc: return exit code 4 for skipped tests mm,mremap: bail out earlier in mremap_to under map pressure mm/sparse: fix a bad comparison mm/memory.c: do_fault: avoid usage of stale vm_area_struct writeback: fix inode cgroup switching comment mm/huge_memory.c: fix "orig_pud" set but not used mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC mm/memcontrol.c: fix bad line in comment mm/cma.c: cma_declare_contiguous: correct err handling mm/page_ext.c: fix an imbalance with kmemleak mm/compaction: pass pgdat to too_many_isolated() instead of zone mm: remove zone_lru_lock() function, access ->lru_lock directly ... |
||
|
Linus Torvalds
|
45802da05e |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- refcount conversions
- Solve the rq->leaf_cfs_rq_list can of worms for real.
- improve power-aware scheduling
- add sysctl knob for Energy Aware Scheduling
- documentation updates
- misc other changes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
kthread: Do not use TIMER_IRQSAFE
kthread: Convert worker lock to raw spinlock
sched/fair: Use non-atomic cpumask_{set,clear}_cpu()
sched/fair: Remove unused 'sd' parameter from select_idle_smt()
sched/wait: Use freezable_schedule() when possible
sched/fair: Prune, fix and simplify the nohz_balancer_kick() comment block
sched/fair: Explain LLC nohz kick condition
sched/fair: Simplify nohz_balancer_kick()
sched/topology: Fix percpu data types in struct sd_data & struct s_data
sched/fair: Simplify post_init_entity_util_avg() by calling it with a task_struct pointer argument
sched/fair: Fix O(nr_cgroups) in the load balancing path
sched/fair: Optimize update_blocked_averages()
sched/fair: Fix insertion in rq->leaf_cfs_rq_list
sched/fair: Add tmp_alone_branch assertion
sched/core: Use READ_ONCE()/WRITE_ONCE() in move_queued_task()/task_rq_lock()
sched/debug: Initialize sd_sysctl_cpus if !CONFIG_CPUMASK_OFFSTACK
sched/pelt: Skip updating util_est when utilization is higher than CPU's capacity
sched/fair: Update scale invariance of PELT
sched/fair: Move the rq_of() helper function
sched/core: Convert task_struct.stack_refcount to refcount_t
...
|
||
 Aneesh Kumar K.V
|
d7fefcc8de |
mm/cma: add PF flag to force non cma alloc
Patch series "mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region", v8. ppc64 uses the CMA area for the allocation of guest page table (hash page table). We won't be able to start guest if we fail to allocate hash page table. We have observed hash table allocation failure because we failed to migrate pages out of CMA region because they were pinned. This happen when we are using VFIO. VFIO on ppc64 pins the entire guest RAM. If the guest RAM pages get allocated out of CMA region, we won't be able to migrate those pages. The pages are also pinned for the lifetime of the guest. Currently we support migration of non-compound pages. With THP and with the addition of hugetlb migration we can end up allocating compound pages from CMA region. This patch series add support for migrating compound pages. This patch (of 4): Add PF_MEMALLOC_NOCMA which make sure any allocation in that context is marked non-movable and hence cannot be satisfied by CMA region. This is useful with get_user_pages_longterm where we want to take a page pin by migrating pages from CMA region. Marking the section PF_MEMALLOC_NOCMA ensures that we avoid unnecessary page migration later. Link: http://lkml.kernel.org/r/20190114095438.32470-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Suggested-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
 Mel Gorman
|
5e1f0f098b |
mm, compaction: capture a page under direct compaction
Compaction is inherently race-prone as a suitable page freed during
compaction can be allocated by any parallel task. This patch uses a
capture_control structure to isolate a page immediately when it is freed
by a direct compactor in the slow path of the page allocator. The
intent is to avoid redundant scanning.
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
Amean fault-both-3 2582.11 ( 0.00%) 2563.68 ( 0.71%)
Amean fault-both-5 4500.26 ( 0.00%) 4233.52 ( 5.93%)
Amean fault-both-7 5819.53 ( 0.00%) 6333.65 ( -8.83%)
Amean fault-both-12 9321.18 ( 0.00%) 9759.38 ( -4.70%)
Amean fault-both-18 9782.76 ( 0.00%) 10338.76 ( -5.68%)
Amean fault-both-24 15272.81 ( 0.00%) 13379.55 * 12.40%*
Amean fault-both-30 15121.34 ( 0.00%) 16158.25 ( -6.86%)
Amean fault-both-32 18466.67 ( 0.00%) 18971.21 ( -2.73%)
Latency is only moderately affected but the devil is in the details. A
closer examination indicates that base page fault latency is reduced but
latency of huge pages is increased as it takes creater care to succeed.
Part of the "problem" is that allocation success rates are close to 100%
even when under pressure and compaction gets harder
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Percentage huge-3 96.70 ( 0.00%) 98.23 ( 1.58%)
Percentage huge-5 96.99 ( 0.00%) 95.30 ( -1.75%)
Percentage huge-7 94.19 ( 0.00%) 97.24 ( 3.24%)
Percentage huge-12 94.95 ( 0.00%) 97.35 ( 2.53%)
Percentage huge-18 96.74 ( 0.00%) 97.30 ( 0.58%)
Percentage huge-24 97.07 ( 0.00%) 97.55 ( 0.50%)
Percentage huge-30 95.69 ( 0.00%) 98.50 ( 2.95%)
Percentage huge-32 96.70 ( 0.00%) 99.27 ( 2.65%)
And scan rates are reduced as expected by 6% for the migration scanner
and 29% for the free scanner indicating that there is less redundant
work.
Compaction migrate scanned 20815362 19573286
Compaction free scanned 16352612 11510663
[mgorman@techsingularity.net: remove redundant check]
Link: http://lkml.kernel.org/r/20190201143853.GH9565@techsingularity.net
Link: http://lkml.kernel.org/r/20190118175136.31341-23-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Linus Torvalds
|
edaed168e1 |
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti update from Thomas Gleixner:
"Just a single change from the anti-performance departement:
- Add a new PR_SPEC_DISABLE_NOEXEC option which allows to apply the
speculation protections on a process without inheriting the state
on exec.
This remedies a situation where a Java-launcher has speculation
protections enabled because that's the default for JVMs which
causes the launched regular harmless processes to inherit the
protection state which results in unintended performance
degradation"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Add PR_SPEC_DISABLE_NOEXEC
|
||
|
Linus Torvalds
|
53a41cb7ed |
Revert "x86/fault: BUG() when uaccess helpers fault on kernel addresses"
This reverts commit
|
||
 Ingo Molnar
|
c9ba7560c5 |
Merge tag 'v5.0-rc6' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org> |