Merge 4.13-rc7 into staging-next

We want the staging and iio fixes in here to handle the merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 4.13-rc7 into char-misc-next

We want the binder fix in here as well for testing and merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Minor page waitqueue cleanups

Tim Chen and Kan Liang have been battling a customer load that shows
extremely long page wakeup lists. The cause seems to be constant NUMA
migration of a hot page that

Minor page waitqueue cleanups

Tim Chen and Kan Liang have been battling a customer load that shows
extremely long page wakeup lists. The cause seems to be constant NUMA
migration of a hot page that is shared across a lot of threads, but the
actual root cause for the exact behavior has not been found.

Tim has a patch that batches the wait list traversal at wakeup time, so
that we at least don't get long uninterruptible cases where we traverse
and wake up thousands of processes and get nasty latency spikes. That
is likely 4.14 material, but we're still discussing the page waitqueue
specific parts of it.

In the meantime, I've tried to look at making the page wait queues less
expensive, and failing miserably. If you have thousands of threads
waiting for the same page, it will be painful. We'll need to try to
figure out the NUMA balancing issue some day, in addition to avoiding
the excessive spinlock hold times.

That said, having tried to rewrite the page wait queues, I can at least
fix up some of the braindamage in the current situation. In particular:

(a) we don't want to continue walking the page wait list if the bit
we're waiting for already got set again (which seems to be one of
the patterns of the bad load). That makes no progress and just
causes pointless cache pollution chasing the pointers.

(b) we don't want to put the non-locking waiters always on the front of
the queue, and the locking waiters always on the back. Not only is
that unfair, it means that we wake up thousands of reading threads
that will just end up being blocked by the writer later anyway.

Also add a comment about the layout of 'struct wait_page_key' - there is
an external user of it in the cachefiles code that means that it has to
match the layout of 'struct wait_bit_key' in the two first members. It
so happens to match, because 'struct page *' and 'unsigned long *' end
up having the same values simply because the page flags are the first
member in struct page.

Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Christopher Lameter <cl@linux.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Merge origin/master into drm-misc-fixes

Backmerge 4.13-rc5 into drm-misc-fixes, it was getting a
little stale.

Signed-off-by: Sean Paul <seanpaul@chromium.org>

Merge tag 'v4.13-rc1' into omap-for-v4.14/mmc-regulator

Linux v4.13-rc1

Merge branch 'for-linus' into for-next

Back-merge 4.13-rc devel branch for later development.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge tag 'asoc-fix-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.13

Quite a few fixes here that have been sent since the merge window,

Merge tag 'asoc-fix-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.13

Quite a few fixes here that have been sent since the merge window, the
biggest one is the fix from Tony for some confusion with the device
property API which was causing issues with the of-graph card. This is
fixed with some changes in the graph API itself as it seemed very likely
to be error prone.

show more ...

Merge airlied/drm-next into drm-intel-next-queued

Resync with upstream to avoid git getting too badly confused. Also, we
have a conflict with the drm_vblank_cleanup removal, which cannot be
resolved

Merge airlied/drm-next into drm-intel-next-queued

Resync with upstream to avoid git getting too badly confused. Also, we
have a conflict with the drm_vblank_cleanup removal, which cannot be
resolved by simply taking our side. Bake that in properly.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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Merge airlied/drm-next into drm-misc-next

I need this to be able to apply the deferred fbdev setup patches, I
need the relevant prep work that landed through the drm-intel tree.

Also squash in conf

Merge airlied/drm-next into drm-misc-next

I need this to be able to apply the deferred fbdev setup patches, I
need the relevant prep work that landed through the drm-intel tree.

Also squash in conflict fixup from Laurent Pinchart.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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sync to Linus v4.13-rc2 for subsystem developers to work against

Merge tag 'v4.13-rc1' into k.o/for-4.13-rc

Linux v4.13-rc1

Merge tag 'v4.13-rc1' into patchwork

Linux v4.13-rc1

* tag 'v4.13-rc1': (11136 commits)
Linux v4.13-rc1
random: reorder READ_ONCE() in get_random_uXX
random: suppress spammy warnings about un

Merge tag 'v4.13-rc1' into patchwork

Linux v4.13-rc1

* tag 'v4.13-rc1': (11136 commits)
Linux v4.13-rc1
random: reorder READ_ONCE() in get_random_uXX
random: suppress spammy warnings about unseeded randomness
replace incorrect strscpy use in FORTIFY_SOURCE
kmod: throttle kmod thread limit
kmod: add test driver to stress test the module loader
MAINTAINERS: give kmod some maintainer love
xtensa: use generic fb.h
fault-inject: add /proc/<pid>/fail-nth
fault-inject: simplify access check for fail-nth
fault-inject: make fail-nth read/write interface symmetric
fault-inject: parse as natural 1-based value for fail-nth write interface
fault-inject: automatically detect the number base for fail-nth write interface
kernel/watchdog.c: use better pr_fmt prefix
MAINTAINERS: move the befs tree to kernel.org
lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int
mm: fix overflow check in expand_upwards()
ubifs: Set double hash cookie also for RENAME_EXCHANGE
ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs
ubifs: Don't leak kernel memory to the MTD
...

show more ...

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:

- Add the SYSTEM_SCHE

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:

- Add the SYSTEM_SCHEDULING bootup state to move various scheduler
debug checks earlier into the bootup. This turns silent and
sporadically deadly bugs into nice, deterministic splats. Fix some
of the splats that triggered. (Thomas Gleixner)

- A round of restructuring and refactoring of the load-balancing and
topology code (Peter Zijlstra)

- Another round of consolidating ~20 of incremental scheduler code
history: this time in terms of wait-queue nomenclature. (I didn't
get much feedback on these renaming patches, and we can still
easily change any names I might have misplaced, so if anyone hates
a new name, please holler and I'll fix it.) (Ingo Molnar)

- sched/numa improvements, fixes and updates (Rik van Riel)

- Another round of x86/tsc scheduler clock code improvements, in hope
of making it more robust (Peter Zijlstra)

- Improve NOHZ behavior (Frederic Weisbecker)

- Deadline scheduler improvements and fixes (Luca Abeni, Daniel
Bristot de Oliveira)

- Simplify and optimize the topology setup code (Lauro Ramos
Venancio)

- Debloat and decouple scheduler code some more (Nicolas Pitre)

- Simplify code by making better use of llist primitives (Byungchul
Park)

- ... plus other fixes and improvements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
sched/cputime: Refactor the cputime_adjust() code
sched/debug: Expose the number of RT/DL tasks that can migrate
sched/numa: Hide numa_wake_affine() from UP build
sched/fair: Remove effective_load()
sched/numa: Implement NUMA node level wake_affine()
sched/fair: Simplify wake_affine() for the single socket case
sched/numa: Override part of migrate_degrades_locality() when idle balancing
sched/rt: Move RT related code from sched/core.c to sched/rt.c
sched/deadline: Move DL related code from sched/core.c to sched/deadline.c
sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled
sched/fair: Spare idle load balancing on nohz_full CPUs
nohz: Move idle balancer registration to the idle path
sched/loadavg: Generalize "_idle" naming to "_nohz"
sched/core: Drop the unused try_get_task_struct() helper function
sched/fair: WARN() and refuse to set buddy when !se->on_rq
sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well
sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c
sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h>
...

show more ...

Merge branch 'WIP.sched/core' into sched/core

Conflicts:
kernel/sched/Makefile

Pick up the waitqueue related renames - it didn't get much feedback,
so it appears to be uncontroversial. Famous las

Merge branch 'WIP.sched/core' into sched/core

Conflicts:
kernel/sched/Makefile

Pick up the waitqueue related renames - it didn't get much feedback,
so it appears to be uncontroversial. Famous last words? ;-)

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming

So I've noticed a number of instances where it was not obvious from the
code whether ->task_list was for a wait-queue head

sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming

So I've noticed a number of instances where it was not obvious from the
code whether ->task_list was for a wait-queue head or a wait-queue entry.

Furthermore, there's a number of wait-queue users where the lists are
not for 'tasks' but other entities (poll tables, etc.), in which case
the 'task_list' name is actively confusing.

To clear this all up, name the wait-queue head and entry list structure
fields unambiguously:

struct wait_queue_head::task_list => ::head
struct wait_queue_entry::task_list => ::entry

For example, this code:

rqw->wait.task_list.next != &wait->task_list

... is was pretty unclear (to me) what it's doing, while now it's written this way:

rqw->wait.head.next != &wait->entry

... which makes it pretty clear that we are iterating a list until we see the head.

Other examples are:

list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
list_for_each_entry(wq, &fence->wait.task_list, task_list) {

... where it's unclear (to me) what we are iterating, and during review it's
hard to tell whether it's trying to walk a wait-queue entry (which would be
a bug), while now it's written as:

list_for_each_entry_safe(pos, next, &x->head, entry) {
list_for_each_entry(wq, &fence->wait.head, entry) {

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>

The wait_bit*() types and APIs are mixed into wait.h, but they
are a pretty orthogonal extension of wait-queues

sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>

The wait_bit*() types and APIs are mixed into wait.h, but they
are a pretty orthogonal extension of wait-queues.

Furthermore, only about 50 kernel files use these APIs, while
over 1000 use the regular wait-queue functionality.

So clean up the main wait.h by moving the wait-bit functionality
out of it, into a separate .h and .c file:

include/linux/wait_bit.h for types and APIs
kernel/sched/wait_bit.c for the implementation

Update all header dependencies.

This reduces the size of wait.h rather significantly, by about 30%.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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sched/wait: Standardize wait_bit_queue naming

So wait-bit-queue head variables are often named:

struct wait_bit_queue *q

... which is a bit ambiguous and super confusing, because
they clearly sug

sched/wait: Standardize wait_bit_queue naming

So wait-bit-queue head variables are often named:

struct wait_bit_queue *q

... which is a bit ambiguous and super confusing, because
they clearly suggest wait-queue head semantics and behavior
(they rhyme with the old wait_queue_t *q naming), while they
are extended wait-queue _entries_, not heads!

They are misnomers in two ways:

- the 'wait_bit_queue' leaves open the question of whether
it's an entry or a head

- the 'q' parameter and local variable naming falsely implies
that it's a 'queue' - while it's an entry.

This resulted in sometimes confusing cases such as:

finish_wait(wq, &q->wait);

where the 'q' is not a wait-queue head, but a wait-bit-queue entry.

So improve this all by standardizing wait-bit-queue nomenclature
similar to wait-queue head naming:

struct wait_bit_queue => struct wait_bit_queue_entry
q => wbq_entry

Which makes it all a much clearer:

struct wait_bit_queue_entry *wbq_entry

... and turns the former confusing piece of code into:

finish_wait(wq_head, &wbq_entry->wq_entry;

which IMHO makes it apparently clear what we are doing,
without having to analyze the context of the code: we are
adding a wait-queue entry to a regular wait-queue head,
which entry is embedded in a wait-bit-queue entry.

I'm not a big fan of acronyms, but repeating wait_bit_queue_entry
in field and local variable names is too long, so Hopefully it's
clear enough that 'wq_' prefixes stand for wait-queues, while
'wbq_' prefixes stand for wait-bit-queues.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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sched/wait: Standardize 'struct wait_bit_queue' wait-queue entry field name

Rename 'struct wait_bit_queue::wait' to ::wq_entry, to more clearly
name it as a wait-queue entry.

Propagate it to a coup

sched/wait: Standardize 'struct wait_bit_queue' wait-queue entry field name

Rename 'struct wait_bit_queue::wait' to ::wq_entry, to more clearly
name it as a wait-queue entry.

Propagate it to a couple of usage sites where the wait-bit-queue internals
are exposed.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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sched/wait: Standardize internal naming of wait-queue heads

The wait-queue head parameters and variables are named in a
couple of ways, we have the following variants currently:

wait_queue_head_t

sched/wait: Standardize internal naming of wait-queue heads

The wait-queue head parameters and variables are named in a
couple of ways, we have the following variants currently:

wait_queue_head_t *q
wait_queue_head_t *wq
wait_queue_head_t *head

In particular the 'wq' naming is ambiguous in the sense whether it's
a wait-queue head or entry name - as entries were often named 'wait'.

( Not to mention the confusion of any readers coming over from
workqueue-land. )

Standardize all this around a single, unambiguous parameter and
variable name:

struct wait_queue_head *wq_head

which is easy to grep for and also rhymes nicely with the wait-queue
entry naming:

struct wait_queue_entry *wq_entry

Also rename:

struct __wait_queue_head => struct wait_queue_head

... and use this struct type to migrate from typedefs usage to 'struct'
usage, which is more in line with existing kernel practices.

Don't touch any external users and preserve the main wait_queue_head_t
typedef.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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sched/wait: Standardize internal naming of wait-queue entries

So the various wait-queue entry variables in include/linux/wait.h
and kernel/sched/wait.c are named in a colorfully inconsistent
way:

sched/wait: Standardize internal naming of wait-queue entries

So the various wait-queue entry variables in include/linux/wait.h
and kernel/sched/wait.c are named in a colorfully inconsistent
way:

wait_queue_entry_t *wait
wait_queue_entry_t *__wait (even in plain C code!)
wait_queue_entry_t *q (!)
wait_queue_entry_t *new (making anyone who knows C++ cringe)
wait_queue_entry_t *old

I think part of the reason for the inconsistency is the constant
apparent confusion about what a wait queue 'head' versus 'entry' is.

( Some of the documentation talks about a 'wait descriptor', which is
the wait-queue entry itself - further adding to the confusion. )

The most common name is 'wait', but that in itself is somewhat
ambiguous as well, as it does not really make it clear whether
it's a wait-queue entry or head.

To improve all this name the wait-queue entry structure parameters
and variables consistently and push through this naming into all
the wait.h and wait.c code:

struct wait_queue_entry *wq_entry

The 'wq_' prefix makes it easy to grep for, and we also use the
opportunity to move away from the typedef to a plain 'struct' naming:
in the kernel we typically reserve typedefs for cases where a
C structure is really small and somewhat opaque - such as pte_t.

wait-queue entries are neither small nor opaque, so use the more
standard 'struct xxx_entry' list management code nomenclature instead.

( We don't touch external users, and we preserve the typedef as well
for actual wait-queue users, to reduce unnecessary churn. )

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

sched/wait: Rename wait_queue_t => wait_queue_entry_t

Rename:

wait_queue_t => wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality

sched/wait: Rename wait_queue_t => wait_queue_entry_t

Rename:

wait_queue_t => wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

Merge tag 'v4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.12-rc5

Merge 'v4.12-rc1' into MTD

Bring a few queued patches in sync for -next development.

Merge branch 'next' into for-linus

Prepare input updates for 4.12 merge window.

Merge branch 'for-4.12/asus' into for-linus