linux-toradex.git/include/linux/ww_mutex.h, branch v4.11-rc6

locking/ww_mutex: Turn off __must_check for now

2017-01-14T11:11:59+00:00

With the ww_mutex inline wrappers gone there's a lot of dormant
anti-patterns emerging in an x86 allyesconfig build:

  kernel/locking/test-ww_mutex.c:80:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  kernel/locking/test-ww_mutex.c:55:3: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  kernel/locking/test-ww_mutex.c:134:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  kernel/locking/test-ww_mutex.c:213:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  kernel/locking/test-ww_mutex.c:177:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  kernel/locking/test-ww_mutex.c:266:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/drm_modeset_lock.c:430:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c:70:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/vgem/vgem_fence.c:193:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/i915/i915_gem_batch_pool.c:125:4: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/i915/i915_gem_execbuffer.c:1302:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/radeon/radeon_prime.c:69:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]
  drivers/gpu/drm/nouveau/nouveau_prime.c:70:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result]

... but we cannot just litter the kernel build log with such warnings.

These need to be fixed separately - turn off the warning for now.

Cc: Nicolai Hähnle 
Cc: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Chris Wilson 
Cc: Daniel Vetter 
Cc: Linus Torvalds 
Cc: Maarten Lankhorst 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/ww_mutex: Fix compilation of __WW_MUTEX_INITIALIZER

2017-01-14T10:37:13+00:00

From conflicting macro parameters, passing the wrong name to
__MUTEX_INITIALIZER and a stray '\', #define __WW_MUTEX_INITIALIZER was
very unhappy.

One unnecessary change was to choose to pass &ww_class instead of
implicitly taking the address of the class within the macro.

Signed-off-by: Chris Wilson 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Maarten Lankhorst 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: 1b375dc30710 ("mutex: Move ww_mutex definitions to ww_mutex.h")
Link: http://lkml.kernel.org/r/20161201114711.28697-2-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar

locking/ww_mutex: Remove the __ww_mutex_lock*() inline wrappers

2017-01-14T10:14:41+00:00

Keep the documentation in the header file since there is no good place
for it in mutex.c: there are two rather different implementations with
different EXPORT_SYMBOLs for each function.

Signed-off-by: Nicolai Hähnle 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= 
Cc: Andrew Morton 
Cc: Chris Wilson 
Cc: Daniel Vetter 
Cc: Linus Torvalds 
Cc: Maarten Lankhorst 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1482346000-9927-6-git-send-email-nhaehnle@gmail.com
Signed-off-by: Ingo Molnar

locking/ww_mutex: Set use_ww_ctx even when locking without a context

2017-01-14T10:14:40+00:00

We will add a new field to struct mutex_waiter.  This field must be
initialized for all waiters if any waiter uses the ww_use_ctx path.

So there is a trade-off: Keep ww_mutex locking without a context on
the faster non-use_ww_ctx path, at the cost of adding the
initialization to all mutex locks (including non-ww_mutexes), or avoid
the additional cost for non-ww_mutex locks, at the cost of adding
additional checks to the use_ww_ctx path.

We take the latter choice.  It may be worth eliminating the users of
ww_mutex_lock(lock, NULL), but there are a lot of them.

Signed-off-by: Nicolai Hähnle 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Chris Wilson 
Cc: Daniel Vetter 
Cc: Linus Torvalds 
Cc: Maarten Lankhorst 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1482346000-9927-5-git-send-email-nhaehnle@gmail.com
Signed-off-by: Ingo Molnar

locking/ww_mutex: Use relaxed atomics

2016-12-06T09:42:03+00:00

The stamp is a sequence number, we don't care about memory ordering.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Boqun Feng 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

tree-wide: replace config_enabled() with IS_ENABLED()

2016-08-04T12:50:07+00:00

The use of config_enabled() against config options is ambiguous.  In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED().  Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc.  makes the intention
clearer.

This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.

I noticed two cases where config_enabled() is used against a tristate
option:

 - config_enabled(CONFIG_HWMON)
  [ drivers/net/wireless/ath/ath10k/thermal.c ]

 - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
  [ drivers/gpu/drm/gma500/opregion.c ]

I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.

Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Acked-by: Kees Cook 
Cc: Stas Sergeev 
Cc: Matt Redfearn 
Cc: Joshua Kinard 
Cc: Jiri Slaby 
Cc: Bjorn Helgaas 
Cc: Borislav Petkov 
Cc: Markos Chandras 
Cc: "Dmitry V. Levin" 
Cc: yu-cheng yu 
Cc: James Hogan 
Cc: Brian Gerst 
Cc: Johannes Berg 
Cc: Peter Zijlstra 
Cc: Al Viro 
Cc: Will Drewry 
Cc: Nikolay Martynov 
Cc: Huacai Chen 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Cc: Daniel Borkmann 
Cc: Leonid Yegoshin 
Cc: Rafal Milecki 
Cc: James Cowgill 
Cc: Greg Kroah-Hartman 
Cc: Ralf Baechle 
Cc: Alex Smith 
Cc: Adam Buchbinder 
Cc: Qais Yousef 
Cc: Jiang Liu 
Cc: Mikko Rapeli 
Cc: Paul Gortmaker 
Cc: Denys Vlasenko 
Cc: Brian Norris 
Cc: Hidehiro Kawai 
Cc: "Luis R. Rodriguez" 
Cc: Andy Lutomirski 
Cc: Ingo Molnar 
Cc: Dave Hansen 
Cc: "Kirill A. Shutemov" 
Cc: Roland McGrath 
Cc: Paul Burton 
Cc: Kalle Valo 
Cc: Viresh Kumar 
Cc: Tony Wu 
Cc: Huaitong Han 
Cc: Sumit Semwal 
Cc: Alexei Starovoitov 
Cc: Juergen Gross 
Cc: Jason Cooper 
Cc: "David S. Miller" 
Cc: Oleg Nesterov 
Cc: Andrea Gelmini 
Cc: David Woodhouse 
Cc: Marc Zyngier 
Cc: Rabin Vincent 
Cc: "Maciej W. Rozycki" 
Cc: David Daney 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mutex: Move ww_mutex definitions to ww_mutex.h

2013-07-12T10:07:46+00:00

Move the definitions for wound/wait mutexes out to a separate
header, ww_mutex.h. This reduces clutter in mutex.h, and
increases readability.

Suggested-by: Linus Torvalds 
Signed-off-by: Maarten Lankhorst 
Acked-by: Peter Zijlstra 
Acked-by: Rik van Riel 
Acked-by: Maarten Lankhorst 
Cc: Dave Airlie 
Link: http://lkml.kernel.org/r/51D675DC.3000907@canonical.com
[ Tidied up the code a bit. ]
Signed-off-by: Ingo Molnar