linux-toradex.git/kernel/sched/wait.c, branch v5.9-rc6

list: add "list_del_init_careful()" to go with "list_empty_careful()"

2020-08-03T03:39:44+00:00

That gives us ordering guarantees around the pair.

Signed-off-by: Linus Torvalds

Add wake_up_interruptible_sync_poll_locked()

2019-10-31T15:12:23+00:00

Add a wakeup call for a case whereby the caller already has the waitqueue
spinlock held.  This can be used by pipes to alter the ring buffer indices
and issue a wakeup under the same spinlock.

Signed-off-by: David Howells 
Acked-by: Peter Zijlstra (Intel)

Remove the nr_exclusive argument from __wake_up_sync_key()

2019-10-23T16:02:34+00:00

Remove the nr_exclusive argument from __wake_up_sync_key() and derived
functions as everything seems to set it to 1.  Note also that if it wasn't
set to 1, it would clear WF_SYNC anyway.

Signed-off-by: David Howells 
Acked-by: Peter Zijlstra (Intel)

sched/wait: Deduplicate code with do-while

2019-06-24T17:23:40+00:00

Statements in the loop's body and before it are identical.
Use do-while to not repeat it.

Signed-off-by: Pavel Begunkov 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/43ffea6ee2152b90dedf962eac851609e4197218.1560256112.git.asml.silence@gmail.com
Signed-off-by: Ingo Molnar

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

kernel/sched/: remove caller signal_pending branch predictions

2019-01-04T21:13:48+00:00

This is already done for us internally by the signal machinery.

Link: http://lkml.kernel.org/r/20181116002713.8474-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso 
Reviewed-by: Andrew Morton 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sched/wait: assert the wait_queue_head lock is held in __wake_up_common

2018-08-22T17:52:47+00:00

Better ensure we actually hold the lock using lockdep than just commenting
on it.  Due to the various exported _locked interfaces it is far too easy
to get the locking wrong.

Link: http://lkml.kernel.org/r/20171214152344.6880-4-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ingo Molnar 
Cc: Al Viro 
Cc: Andrea Arcangeli 
Cc: Ingo Molnar 
Cc: Jason Baron 
Cc: Matthew Wilcox 
Cc: Mike Rapoport 
Cc: Peter Zijlstra 
Cc: Davidlohr Bueso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sched/Documentation: Update wake_up() & co. memory-barrier guarantees

2018-07-17T07:30:34+00:00

Both the implementation and the users' expectation [1] for the various
wakeup primitives have evolved over time, but the documentation has not
kept up with these changes: brings it into 2018.

[1] http://lkml.kernel.org/r/20180424091510.GB4064@hirez.programming.kicks-ass.net

Also applied feedback from Alan Stern.

Suggested-by: Peter Zijlstra 
Signed-off-by: Andrea Parri 
Signed-off-by: Paul E. McKenney 
Acked-by: Peter Zijlstra (Intel) 
Cc: Akira Yokosawa 
Cc: Alan Stern 
Cc: Boqun Feng 
Cc: Daniel Lustig 
Cc: David Howells 
Cc: Jade Alglave 
Cc: Jonathan Corbet 
Cc: Linus Torvalds 
Cc: Luc Maranget 
Cc: Nicholas Piggin 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-arch@vger.kernel.org
Cc: parri.andrea@gmail.com
Link: http://lkml.kernel.org/r/20180716180605.16115-12-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar

sched/core: Use smp_mb() in wake_woken_function()

2018-07-17T07:30:33+00:00

wake_woken_function() synchronizes with wait_woken() as follows:

  [wait_woken]                       [wake_woken_function]

  entry->flags &= ~wq_flag_woken;    condition = true;
  smp_mb();                          smp_wmb();
  if (condition)                     wq_entry->flags |= wq_flag_woken;
     break;

This commit replaces the above smp_wmb() with an smp_mb() in order to
guarantee that either wait_woken() sees the wait condition being true
or the store to wq_entry->flags in woken_wake_function() follows the
store in wait_woken() in the coherence order (so that the former can
eventually be observed by wait_woken()).

The commit also fixes a comment associated to set_current_state() in
wait_woken(): the comment pairs the barrier in set_current_state() to
the above smp_wmb(), while the actual pairing involves the barrier in
set_current_state() and the barrier executed by the try_to_wake_up()
in wake_woken_function().

Signed-off-by: Andrea Parri 
Signed-off-by: Paul E. McKenney 
Acked-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20180716180605.16115-10-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar

sched/headers: Simplify and clean up header usage in the scheduler

2018-03-04T11:39:29+00:00

Do the following cleanups and simplifications:

 - sched/sched.h already includes , so no need to
   include it in sched/core.c again.

 - order the  headers alphabetically

 - add all  headers to kernel/sched/sched.h

 - remove all unnecessary includes from the .c files that
   are already included in kernel/sched/sched.h.

Finally, make all scheduler .c files use a single common header:

  #include "sched.h"

... which now contains a union of the relied upon headers.

This makes the various .c files easier to read and easier to handle.

Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar