| Commit message (Collapse) | Author | Age |
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* refs/heads/tmp-ceee5bd
BACKPORT: arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinux
sched/core: fix have_sched_energy_data build warning
sched/core: Warn if ENERGY_AWARE is enabled but data is missing
sched: walt: Correct WALT window size initialization
FROMLIST: sched/fair: Use wake_q length as a hint for wake_wide
sched: WALT: account cumulative window demand
sched/fair: remove useless variable in find_best_target
sched/tune: access schedtune_initialized under CGROUP_SCHEDTUNE
sched/fair: consider task utilization in group_max_util()
sched/fair: consider task utilization in group_norm_util()
sched/fair: enforce EAS mode
sched/fair: ignore backup CPU when not valid
sched/fair: trace energy_diff for non boosted tasks
UPSTREAM: sched/fair: Sync task util before slow-path wakeup
UPSTREAM: sched/fair: Fix usage of find_idlest_group() when the local group is idlest
UPSTREAM: sched/fair: Fix usage of find_idlest_group() when no groups are allowed
BACKPORT: sched/fair: Fix find_idlest_group when local group is not allowed
UPSTREAM: sched/fair: Remove unnecessary comparison with -1
BACKPORT: sched/fair: Move select_task_rq_fair slow-path into its own function
UPSTREAM: sched/fair: Force balancing on nohz balance if local group has capacity
UPSTREAM: sched/core: Add missing update_rq_clock() call in set_user_nice()
UPSTREAM: sched/core: Add missing update_rq_clock() call for task_hot()
UPSTREAM: sched/core: Add missing update_rq_clock() in detach_task_cfs_rq()
UPSTREAM: sched/core: Add missing update_rq_clock() in post_init_entity_util_avg()
UPSTREAM: sched/core: Fix find_idlest_group() for fork
BACKPORT: sched/fair: Fix PELT integrity for new tasks
BACKPORT: sched/cgroup: Fix cpu_cgroup_fork() handling
UPSTREAM: sched/fair: Fix and optimize the fork() path
BACKPORT: sched/fair: Make it possible to account fair load avg consistently
cpufreq/sched: Consider max cpu capacity when choosing frequencies
Linux 4.4.95
FS-Cache: fix dereference of NULL user_key_payload
fscrypto: require write access to mount to set encryption policy
KEYS: Fix race between updating and finding a negative key
fscrypt: fix dereference of NULL user_key_payload
f2fs crypto: add missing locking for keyring_key access
f2fs crypto: replace some BUG_ON()'s with error checks
sched/autogroup: Fix autogroup_move_group() to never skip sched_move_task()
parisc: Fix double-word compare and exchange in LWS code on 32-bit kernels
parisc: Avoid trashing sr2 and sr3 in LWS code
pkcs7: Prevent NULL pointer dereference, since sinfo is not always set.
KEYS: don't let add_key() update an uninstantiated key
lib/digsig: fix dereference of NULL user_key_payload
KEYS: encrypted: fix dereference of NULL user_key_payload
rtlwifi: rtl8821ae: Fix connection lost problem
clockevents/drivers/cs5535: Improve resilience to spurious interrupts
bus: mbus: fix window size calculation for 4GB windows
brcmsmac: make some local variables 'static const' to reduce stack size
i2c: ismt: Separate I2C block read from SMBus block read
ALSA: hda: Remove superfluous '-' added by printk conversion
ALSA: seq: Enable 'use' locking in all configurations
drm/nouveau/mmu: flush tlbs before deleting page tables
drm/nouveau/bsp/g92: disable by default
can: esd_usb2: Fix can_dlc value for received RTR, frames
usb: musb: Check for host-mode using is_host_active() on reset interrupt
usb: musb: sunxi: Explicitly release USB PHY on exit
can: gs_usb: fix busy loop if no more TX context is available
ALSA: usb-audio: Add native DSD support for Pro-Ject Pre Box S2 Digital
usb: hub: Allow reset retry for USB2 devices on connect bounce
usb: quirks: add quirk for WORLDE MINI MIDI keyboard
usb: cdc_acm: Add quirk for Elatec TWN3
USB: serial: metro-usb: add MS7820 device id
USB: core: fix out-of-bounds access bug in usb_get_bos_descriptor()
USB: devio: Revert "USB: devio: Don't corrupt user memory"
ANDROID: binder: show high watermark of alloc->pages.
ANDROID: binder: Add thread->process_todo flag.
UPSTREAM: arm64: compat: Remove leftover variable declaration
ANDROID: sched/fair: Select correct capacity state for energy_diff
Revert "UPSTREAM: efi/libstub/arm64: Set -fpie when building the EFI stub"
cpufreq: schedutil: clamp util to CPU maximum capacity
FROMLIST: android: binder: Fix null ptr dereference in debug msg
FROMLIST: android: binder: Change binder_shrinker to static
cpufreq/sched: Use cpu max freq rather than policy max
Conflicts:
include/linux/sched.h
kernel/sched/core.c
kernel/sched/fair.c
Change-Id: I2751f851df741f00e797deaf2119872b3dced655
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>
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(from https://patchwork.kernel.org/patch/9895261/)
This patch adds a parameter to select_task_rq, sibling_count_hint
allowing the caller, where it has this information, to inform the
sched_class the number of tasks that are being woken up as part of
the same event.
The wake_q mechanism is one case where this information is available.
select_task_rq_fair can then use the information to detect that it
needs to widen the search space for task placement in order to avoid
overloading the last-level cache domain's CPUs.
* * *
The reason I am investigating this change is the following use case
on ARM big.LITTLE (asymmetrical CPU capacity): 1 task per CPU, which
all repeatedly do X amount of work then
pthread_barrier_wait (i.e. sleep until the last task finishes its X
and hits the barrier). On big.LITTLE, the tasks which get a "big" CPU
finish faster, and then those CPUs pull over the tasks that are still
running:
v CPU v ->time->
-------------
0 (big) 11111 /333
-------------
1 (big) 22222 /444|
-------------
2 (LITTLE) 333333/
-------------
3 (LITTLE) 444444/
-------------
Now when task 4 hits the barrier (at |) and wakes the others up,
there are 4 tasks with prev_cpu=<big> and 0 tasks with
prev_cpu=<little>. want_affine therefore means that we'll only look
in CPUs 0 and 1 (sd_llc), so tasks will be unnecessarily coscheduled
on the bigs until the next load balance, something like this:
v CPU v ->time->
------------------------
0 (big) 11111 /333 31313\33333
------------------------
1 (big) 22222 /444|424\4444444
------------------------
2 (LITTLE) 333333/ \222222
------------------------
3 (LITTLE) 444444/ \1111
------------------------
^^^
underutilization
So, I'm trying to get want_affine = 0 for these tasks.
I don't _think_ any incarnation of the wakee_flips mechanism can help
us here because which task is waker and which tasks are wakees
generally changes with each iteration.
However pthread_barrier_wait (or more accurately FUTEX_WAKE) has the
nice property that we know exactly how many tasks are being woken, so
we can cheat.
It might be a disadvantage that we "widen" _every_ task that's woken in
an event, while select_idle_sibling would work fine for the first
sd_llc_size - 1 tasks.
IIUC, if wake_affine() behaves correctly this trick wouldn't be
necessary on SMP systems, so it might be best guarded by the presence
of SD_ASYM_CPUCAPACITY?
* * *
Final note..
In order to observe "perfect" behaviour for this use case, I also had
to disable the TTWU_QUEUE sched feature. Suppose during the wakeup
above we are working through the work queue and have placed tasks 3
and 2, and are about to place task 1:
v CPU v ->time->
--------------
0 (big) 11111 /333 3
--------------
1 (big) 22222 /444|4
--------------
2 (LITTLE) 333333/ 2
--------------
3 (LITTLE) 444444/ <- Task 1 should go here
--------------
If TTWU_QUEUE is enabled, we will not yet have enqueued task
2 (having instead sent a reschedule IPI) or attached its load to CPU
2. So we are likely to also place task 1 on cpu 2. Disabling
TTWU_QUEUE means that we enqueue task 2 before placing task 1,
solving this issue. TTWU_QUEUE is there to minimise rq lock
contention, and I guess that this contention is less of an issue on
big.LITTLE systems since they have relatively few CPUs, which
suggests the trade-off makes sense here.
Change-Id: I2080302839a263e0841a89efea8589ea53bbda9c
Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
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Current window based load tracking only saves history for five
windows. A historically heavy task's heavy load will be completely
forgotten after five windows of light load. Even before the five
window expires, a heavy task wakes up on same CPU it used to run won't
trigger any frequency change until end of the window. It would starve
for the entire window. It also adds one "small" load window to
history because it's accumulating load at a low frequency, further
reducing the tracked load for this heavy task.
Ideally, scheduler should be able to identify such tasks and notify
governor to increase frequency immediately after it wakes up.
Add a histogram for each task to track a much longer load history. A
prediction will be made based on runtime of previous or current
window, histogram data and load tracked in recent windows. Prediction
of all tasks that is currently running or runnable on a CPU is
aggregated and reported to CPUFreq governor in sched_get_cpus_busy().
sched_get_cpus_busy() now returns predicted busy time in addition
to previous window busy time and new task busy time, scaled to
the CPU maximum possible frequency.
Tunables:
- /proc/sys/kernel/sched_gov_alert_freq (KHz)
This tunable can be used to further filter the notifications.
Frequency alert notification is sent only when the predicted
load exceeds previous window load by sched_gov_alert_freq converted to
load.
Change-Id: If29098cd2c5499163ceaff18668639db76ee8504
Suggested-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
[joonwoop@codeaurora.org: fixed merge conflicts around __migrate_task()
and removed changes for CONFIG_SCHED_QHMP.]
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When a new window starts for a task and the task is on a rq, scheduler
decreases rq's cumulative_runnable_avg momentarily, re-account task's
demand and increases rq's cumulative_runnable_avg with newly accounted
task's demand. Therefore there is short time period that rq's
cumulative_runnable_avg is less than what it's supposed to be.
Meanwhile, there is chance that other CPU is in search of best CPU to place
a task and makes suboptimal decision with momentarily stale
cumulative_runnable_avg.
Fix such issue by adding or subtracting of delta between task's old
and new demand instead of decrementing and incrementing of entire task's
load.
Change-Id: I3c9329961e6f96e269fa13359e7d1c39c4973ff2
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
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Key hmp stats (nr_big_tasks, nr_small_tasks and
cumulative_runnable_average) are currently maintained per-cpu in
'struct rq'. Merge those stats in their own structure (struct
hmp_sched_stats) and modify impacted functions to deal with the newly
introduced structure. This cleanup is required for a subsequent patch
which fixes various issues with use of CFS_BANDWIDTH feature in HMP
scheduler.
Change-Id: Ieffc10a3b82a102f561331bc385d042c15a33998
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
[rameezmustafa@codeaurora.org: Port to msm-3.18]
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
[joonwoop@codeaurora.org: fixed conflict in __update_load_avg().]
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
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Give every class a set_cpus_allowed() method, this enables some small
optimization in the RT,DL implementation by avoiding a double
cpumask_weight() call.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.614517487@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Chris bisected a NULL pointer deference in task_sched_runtime() to
commit 6e998916dfe3 'sched/cputime: Fix clock_nanosleep()/clock_gettime()
inconsistency'.
Chris observed crashes in atop or other /proc walking programs when he
started fork bombs on his machine. He assumed that this is a new exit
race, but that does not make any sense when looking at that commit.
What's interesting is that, the commit provides update_curr callbacks
for all scheduling classes except stop_task and idle_task.
While nothing can ever hit that via the clock_nanosleep() and
clock_gettime() interfaces, which have been the target of the commit in
question, the author obviously forgot that there are other code paths
which invoke task_sched_runtime()
do_task_stat(()
thread_group_cputime_adjusted()
thread_group_cputime()
task_cputime()
task_sched_runtime()
if (task_current(rq, p) && task_on_rq_queued(p)) {
update_rq_clock(rq);
up->sched_class->update_curr(rq);
}
If the stats are read for a stomp machine task, aka 'migration/N' and
that task is current on its cpu, this will happily call the NULL pointer
of stop_task->update_curr. Ooops.
Chris observation that this happens faster when he runs the fork bomb
makes sense as the fork bomb will kick migration threads more often so
the probability to hit the issue will increase.
Add the missing update_curr callbacks to the scheduler classes stop_task
and idle_task. While idle tasks cannot be monitored via /proc we have
other means to hit the idle case.
Fixes: 6e998916dfe3 'sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency'
Reported-by: Chris Mason <clm@fb.com>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We always use resched_task() with rq->curr argument.
It's not possible to reschedule any task but rq's current.
The patch introduces resched_curr(struct rq *) to
replace all of the repeating patterns. The main aim
is cleanup, but there is a little size profit too:
(before)
$ size kernel/sched/built-in.o
text data bss dec hex filename
155274 16445 7042 178761 2ba49 kernel/sched/built-in.o
$ size vmlinux
text data bss dec hex filename
7411490 1178376 991232 9581098 92322a vmlinux
(after)
$ size kernel/sched/built-in.o
text data bss dec hex filename
155130 16445 7042 178617 2b9b9 kernel/sched/built-in.o
$ size vmlinux
text data bss dec hex filename
7411362 1178376 991232 9580970 9231aa vmlinux
I was choosing between resched_curr() and resched_rq(),
and the first name looks better for me.
A little lie in Documentation/trace/ftrace.txt. I have not
actually collected the tracing again. With a hope the patch
won't make execution times much worse :)
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140628200219.1778.18735.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We close idle_exit_fair() bracket in case of we've pulled something or we've received
task of high priority class.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/1394098315.19290.10.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Remove a few gratuitous #ifdefs in pick_next_task*().
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-nnzddp5c4fijyzzxxrwlxghf@git.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Dan Carpenter reported:
> kernel/sched/rt.c:1347 pick_next_task_rt() warn: variable dereferenced before check 'prev' (see line 1338)
> kernel/sched/deadline.c:1011 pick_next_task_dl() warn: variable dereferenced before check 'prev' (see line 1005)
Kirill also spotted that migrate_tasks() will have an instant NULL
deref because pick_next_task() will immediately deref prev.
Instead of fixing all the corner cases because migrate_tasks() can
pass in a NULL prev task in the unlikely case of hot-un-plug, provide
a fake task such that we can remove all the NULL checks from the far
more common paths.
A further problem; not previously spotted; is that because we pushed
pre_schedule() and idle_balance() into pick_next_task() we now need to
avoid those getting called and pulling more tasks on our dying CPU.
We avoid pull_{dl,rt}_task() by setting fake_task.prio to MAX_PRIO+1.
We also note that since we call pick_next_task() exactly the amount of
times we have runnable tasks present, we should never land in
idle_balance().
Fixes: 38033c37faab ("sched: Push down pre_schedule() and idle_balance()")
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Kirill Tkhai <tkhai@yandex.ru>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140212094930.GB3545@laptop.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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This patch both merged idle_balance() and pre_schedule() and pushes
both of them into pick_next_task().
Conceptually pre_schedule() and idle_balance() are rather similar,
both are used to pull more work onto the current CPU.
We cannot however first move idle_balance() into pre_schedule_fair()
since there is no guarantee the last runnable task is a fair task, and
thus we would miss newidle balances.
Similarly, the dl and rt pre_schedule calls must be ran before
idle_balance() since their respective tasks have higher priority and
it would not do to delay their execution searching for less important
tasks first.
However, by noticing that pick_next_tasks() already traverses the
sched_class hierarchy in the right order, we can get the right
behaviour and do away with both calls.
We must however change the special case optimization to also require
that prev is of sched_class_fair, otherwise we can miss doing a dl or
rt pull where we needed one.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-a8k6vvaebtn64nie345kx1je@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The idle post_schedule flag is just a vile waste of time, furthermore
it appears unneeded, move the idle_enter_fair() call into
pick_next_task_idle().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: alex.shi@linaro.org
Cc: mingo@kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-aljykihtxJt3mkokxi0qZurb@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In order to avoid having to do put/set on a whole cgroup hierarchy
when we context switch, push the put into pick_next_task() so that
both operations are in the same function. Further changes then allow
us to possibly optimize away redundant work.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Use the new stop_two_cpus() to implement migrate_swap(), a function that
flips two tasks between their respective cpus.
I'm fairly sure there's a less crude way than employing the stop_two_cpus()
method, but everything I tried either got horribly fragile and/or complex. So
keep it simple for now.
The notable detail is how we 'migrate' tasks that aren't runnable
anymore. We'll make it appear like we migrated them before they went to
sleep. The sole difference is the previous cpu in the wakeup path, so we
override this.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1381141781-10992-39-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The scheduler doesn't yet fully support environments
with a single task running without a periodic tick.
In order to ensure we still maintain the duties of scheduler_tick(),
keep at least 1 tick per second.
This makes sure that we keep the progression of various scheduler
accounting and background maintainance even with a very low granularity.
Examples include cpu load, sched average, CFS entity vruntime,
avenrun and events such as load balancing, amongst other details
handled in sched_class::task_tick().
This limitation will be removed in the future once we get
these individual items to work in full dynticks CPUs.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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The current update of the rq's load can be erroneous when RT
tasks are involved.
The update of the load of a rq that becomes idle, is done only
if the avg_idle is less than sysctl_sched_migration_cost. If RT
tasks and short idle duration alternate, the runnable_avg will
not be updated correctly and the time will be accounted as idle
time when a CFS task wakes up.
A new idle_enter function is called when the next task is the
idle function so the elapsed time will be accounted as run time
in the load of the rq, whatever the average idle time is. The
function update_rq_runnable_avg is removed from idle_balance.
When a RT task is scheduled on an idle CPU, the update of the
rq's load is not done when the rq exit idle state because CFS's
functions are not called. Then, the idle_balance, which is
called just before entering the idle function, updates the rq's
load and makes the assumption that the elapsed time since the
last update, was only running time.
As a consequence, the rq's load of a CPU that only runs a
periodic RT task, is close to LOAD_AVG_MAX whatever the running
duration of the RT task is.
A new idle_exit function is called when the prev task is the
idle function so the elapsed time will be accounted as idle time
in the rq's load.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: linaro-kernel@lists.linaro.org
Cc: peterz@infradead.org
Cc: pjt@google.com
Cc: fweisbec@gmail.com
Cc: efault@gmx.de
Link: http://lkml.kernel.org/r/1366302867-5055-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Thanks to Charles Wang for spotting the defects in the current code:
- If we go idle during the sample window -- after sampling, we get a
negative bias because we can negate our own sample.
- If we wake up during the sample window we get a positive bias
because we push the sample to a known active period.
So rewrite the entire nohz load-avg muck once again, now adding
copious documentation to the code.
Reported-and-tested-by: Doug Smythies <dsmythies@telus.net>
Reported-and-tested-by: Charles Wang <muming.wq@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1340373782.18025.74.camel@twins
[ minor edits ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Change sched_*.c to sched/*.c in documentation and comments.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F795CAC.9080206@ct.jp.nec.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There's too many sched*.[ch] files in kernel/, give them their own
directory.
(No code changed, other than Makefile glue added.)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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