linux-stable.git/kernel/semaphore.c, branch master

locking: Move the semaphore core to kernel/locking/

2013-11-06T06:55:22+00:00

Suggested-by: Ingo Molnar 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-vmw5sf6vzmua1z6nx1cg69h2@git.kernel.org
Signed-off-by: Ingo Molnar

semaphore: use `bool' type for semaphore_waiter's up

2013-05-01T00:04:08+00:00

Signed-off-by: liguang 
Cc: Jiri Kosina 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

semaphore: use unlikely() for down's timeout

2013-05-01T00:04:08+00:00

Signed-off-by: liguang 
Cc: Jiri Kosina 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

semaphore: fix improper comment reference to mutex

2012-04-06T00:15:55+00:00

Replace "mutex" with "semaphore" in down_trylock comment

Signed-off-by: Lucia Rosculete 
Signed-off-by: Jiri Kosina

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12+00:00

The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include 
  +#include 

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker

locking, semaphores: Annotate inner lock as raw

2011-09-13T09:11:57+00:00

There is no reason to have the spin_lock protecting the semaphore
preemptible on -rt. Annotate it as a raw_spinlock.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

( On rt this also solves lockdep complaining about the
  rt_mutex.wait_lock being not initialized. )

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

semaphore: __down_common: use signal_pending_state()

2008-08-05T21:33:47+00:00

Change __down_common() to use signal_pending_state() instead of open
coding.

The changes in kernel/semaphore.o are just artifacts, the state checks are
optimized away.

Signed-off-by: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Matthew Wilcox 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mmiotrace broken in linux-next (8-bit writes only)

2008-07-01T08:14:06+00:00

The moment mmiotrace is enabled, I hit a NULL deref in:

IP: [] __trace_special+0x17c/0x23a
Call Trace:
 [] ftrace_special+0x6f/0x9a
 [] down+0x19/0x4a
 [] acquire_console_sem+0x42/0x58
 [] con_flush_chars+0x28/0x43
 [] write_chan+0x22e/0x334
 [] ? default_wake_function+0x0/0xf
 [] tty_write+0x195/0x228
 [] ? write_chan+0x0/0x334
 [] vfs_write+0xae/0x137
 [] sys_write+0x47/0x70
 [] system_call_after_swapgs+0x7b/0x80

which means 'entry' in __trace_special() is NULL.

[ mingo@elte.hu: that ftrace_special() was a leftover. ]

Signed-off-by: Pekka Paalanen 
Cc: Steven Rostedt 
Cc: proski@gnu.org
Cc: "Vegard Nossum" 
Signed-off-by: Ingo Molnar

ftrace: stacktrace fix

2008-05-23T20:34:56+00:00

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

Revert "semaphore: fix"

2008-05-11T03:43:22+00:00

This reverts commit bf726eab3711cf192405d21688a4b21e07b6188a, as it has
been reported to cause a regression with processes stuck in __down(),
apparently because some missing wakeup.

Quoth Sven Wegener:
 "I'm currently investigating a regression that has showed up with my
  last git pull yesterday.  Bisecting the commits showed bf726e
  "semaphore: fix" to be the culprit, reverting it fixed the issue.

  Symptoms: During heavy filesystem usage (e.g.  a kernel compile) I get
  several compiler processes in uninterruptible sleep, blocking all i/o
  on the filesystem.  System is an Intel Core 2 Quad running a 64bit
  kernel and userspace.  Filesystem is xfs on top of lvm.  See below for
  the output of sysrq-w."

See

	http://lkml.org/lkml/2008/5/10/45

for full report.

In the meantime, we can just fix the BKL performance regression by
reverting back to the good old BKL spinlock implementation instead,
since any sleeping lock will generally perform badly, especially if it
tries to be fair.

Reported-by: Sven Wegener 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Signed-off-by: Linus Torvalds