Improve consistency of '#error' directive messages

Remove the use of contractions and use proper punctuation in #error
directive messages that discourage the direct inclusion of header files.

Link:

Improve consistency of '#error' directive messages

Remove the use of contractions and use proper punctuation in #error
directive messages that discourage the direct inclusion of header files.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nataniel Farzan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

locking: Detect includes rwlock.h outside of spinlock.h

From: Michael S. Tsirkin <[email protected]>

The check for __LINUX_SPINLOCK_H within rwlock.h (and other files)
detects the direct include of th

locking: Detect includes rwlock.h outside of spinlock.h

From: Michael S. Tsirkin <[email protected]>

The check for __LINUX_SPINLOCK_H within rwlock.h (and other files)
detects the direct include of the header file if it is at the very
beginning of the include section.
If it is listed later then chances are high that spinlock.h was already
included (including rwlock.h) and the additional listing of rwlock.h
will not cause any failure.

On PREEMPT_RT this additional rwlock.h will lead to compile failures
since it uses a different rwlock implementation.

Add __LINUX_INSIDE_SPINLOCK_H to spinlock.h and check for this instead
of __LINUX_SPINLOCK_H to detect wrong includes. This will help detect
direct includes of rwlock.h with without PREEMPT_RT enabled.

[ bigeasy: add remaining __LINUX_SPINLOCK_H user and rewrite
commit description. ]

Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

show more ...

locking/rwlocks: introduce write_lock_nested

In preparation for converting bit_spin_lock to rwlock in zsmalloc so
that multiple writers of zspages can run at the same time but those
zspages are supp

locking/rwlocks: introduce write_lock_nested

In preparation for converting bit_spin_lock to rwlock in zsmalloc so
that multiple writers of zspages can run at the same time but those
zspages are supposed to be different zspage instance. Thus, it's not
deadlock. This patch adds write_lock_nested to support the case for
LOCKDEP.

[[email protected]: fix write_lock_nested for RT]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fixup write_lock_nested() implementation]
Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Tested-by: Sebastian Andrzej Siewior <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Naresh Kamboju <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

locking: Remove spin_lock_flags() etc

parisc, ia64 and powerpc32 are the only remaining architectures that
provide custom arch_{spin,read,write}_lock_flags() functions, which are
meant to re-enable

locking: Remove spin_lock_flags() etc

parisc, ia64 and powerpc32 are the only remaining architectures that
provide custom arch_{spin,read,write}_lock_flags() functions, which are
meant to re-enable interrupts while waiting for a spinlock.

However, none of these can actually run into this codepath, because
it is only called on architectures without CONFIG_GENERIC_LOCKBREAK,
or when CONFIG_DEBUG_LOCK_ALLOC is set without CONFIG_LOCKDEP, and none
of those combinations are possible on the three architectures.

Going back in the git history, it appears that arch/mn10300 may have
been able to run into this code path, but there is a good chance that
it never worked. On the architectures that still exist, it was
already impossible to hit back in 2008 after the introduction of
CONFIG_GENERIC_LOCKBREAK, and possibly earlier.

As this is all dead code, just remove it and the helper functions built
around it. For arch/ia64, the inline asm could be cleaned up, but
it seems safer to leave it untouched.

Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Helge Deller <[email protected]> # parisc
Link: https://lore.kernel.org/r/[email protected]

show more ...

locking/rwlocks: Add contention detection for rwlocks

rwlocks do not currently have any facility to detect contention
like spinlocks do. In order to allow users of rwlocks to better manage
latency,

locking/rwlocks: Add contention detection for rwlocks

rwlocks do not currently have any facility to detect contention
like spinlocks do. In order to allow users of rwlocks to better manage
latency, add contention detection for queued rwlocks.

CC: Ingo Molnar <[email protected]>
CC: Will Deacon <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Acked-by: Waiman Long <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Signed-off-by: Ben Gardon <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...

locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations

The arch_{read,spin,write}_lock_flags() macros are simply mapped to the
non-flags versions by the majority of architect

locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations

The arch_{read,spin,write}_lock_flags() macros are simply mapped to the
non-flags versions by the majority of architectures, so do this in core
code and remove the dummy implementations. Also remove the implementation
in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call
local_irq_save(flags) anyway.

Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

show more ...

locking/core: Remove {read,spin,write}_can_lock()

Outside of the locking code itself, {read,spin,write}_can_lock() have no
users in tree. Apparmor (the last remaining user of write_can_lock()) got
m

locking/core: Remove {read,spin,write}_can_lock()

Outside of the locking code itself, {read,spin,write}_can_lock() have no
users in tree. Apparmor (the last remaining user of write_can_lock()) got
moved over to lockdep by the previous patch.

This patch removes the use of {read,spin,write}_can_lock() from the
BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the
lock status, and subsequently removes the unused macros altogether. They
aren't guaranteed to work in a concurrent environment and can give
incorrect results in the case of qrwlock.

Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

show more ...

locking: Make sparse work with inline spinlocks and rwlocks

Currently sparse does not work with inline spinlock and rwlock functions.
The problem is that they do not use the __acquires/__releases o

locking: Make sparse work with inline spinlocks and rwlocks

Currently sparse does not work with inline spinlock and rwlock functions.
The problem is that they do not use the __acquires/__releases out-of-line
functions, but use inline functions with no sparse annotations.

This patch adds the appropriate annotations to make it work properly.

Signed-off-by: Luca Barbieri <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>

show more ...

locking: Cleanup the name space completely

Make the name space hierarchy of locking functions consistent:
raw_spin* -> _raw_spin* -> __raw_spin*

No functional change.

Signed-off-by: Thomas Gl

locking: Cleanup the name space completely

Make the name space hierarchy of locking functions consistent:
raw_spin* -> _raw_spin* -> __raw_spin*

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>

show more ...

locking: Further name space cleanups

The name space hierarchy for the internal lock functions is now a bit
backwards. raw_spin* functions map to _spin* which use __spin*, while
we would like to have

locking: Further name space cleanups

The name space hierarchy for the internal lock functions is now a bit
backwards. raw_spin* functions map to _spin* which use __spin*, while
we would like to have _raw_spin* and __raw_spin*.

_raw_spin* is already used by lock debugging, so rename those funtions
to do_raw_spin* to free up the _raw_spin* name space.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>

show more ...

locking: Convert raw_rwlock functions to arch_rwlock

Name space cleanup for rwlock functions. No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra <pet

locking: Convert raw_rwlock functions to arch_rwlock

Name space cleanup for rwlock functions. No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: David S. Miller <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: [email protected]

show more ...

locking: Split rwlock from spinlock headers

Move the rwlock defines and inlines into separate header files. This
makes the selection for -rt easier.

No functional change.

Signed-off-by: Thomas Gle

locking: Split rwlock from spinlock headers

Move the rwlock defines and inlines into separate header files. This
makes the selection for -rt easier.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>

show more ...