linux-toradex.git/include/linux/rcupdate.h, branch v3.6.4

rcu: Fix broken strings in RCU's source code.

2012-07-06T13:01:49+00:00

Although the C language allows you to break strings across lines, doing
this makes it hard for people to find the Linux kernel code corresponding
to a given console message.  This commit therefore fixes broken strings
throughout RCU's source code.

Suggested-by: Josh Triplett 
Suggested-by: Ingo Molnar 
Signed-off-by: Paul E. McKenney

Merge branches 'bigrtm.2012.07.04a', 'doctorture.2012.07.02a', 'fixes.2012.07.06a' and 'fnh.2012.07.02a' into HEAD

2012-07-06T12:59:30+00:00

bigrtm: First steps towards getting RCU out of the way of
	tens-of-microseconds real-time response on systems compiled
	with NR_CPUS=4096.  Also cleanups for and increased concurrency
	of rcu_barrier() family of primitives.
doctorture: rcutorture and documentation improvements.
fixes:  Miscellaneous fixes.
fnh: RCU_FAST_NO_HZ fixes and improvements.

rcu: Fix qlen_lazy breakage

2012-07-02T19:34:43+00:00

Commit d8169d4c (Make __kfree_rcu() less dependent on compiler choices)
created a macro out of an inline function in order to avoid build
breakage for certain combinations of gcc flags.  Unfortunately, it also
converted a kfree_call_rcu() to a call_rcu(), which made the rcu_data
structure's ->qlen_lazy field lose counts.  This commit therefore changes
the call_rcu() back to kfree_call_rcu().

Signed-off-by: Paul E. McKenney 
Signed-off-by: Paul E. McKenney

rcu: Make __call_rcu() handle invocation from idle

2012-07-02T19:34:24+00:00

Although __call_rcu() is handled correctly when called from a momentary
non-idle period, if it is called on a CPU that RCU believes to be idle
on RCU_FAST_NO_HZ kernels, the callback might be indefinitely postponed.
This commit therefore ensures that RCU is aware of the new callback and
has a chance to force the CPU out of dyntick-idle mode when a new callback
is posted.

Reported-by: Frederic Weisbecker 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcu: Remove function versions of __kfree_rcu and __is_kfree_rcu_offset

2012-07-02T19:34:24+00:00

Commit d8169d4c (Make __kfree_rcu() less dependent on compiler choices)
added cpp macro versions of __kfree_rcu() and __is_kfree_rcu_offset(),
but failed to remove the old inline-function versions.  This commit does
this cleanup.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcu: Consolidate tree/tiny __rcu_read_{,un}lock() implementations

2012-07-02T19:34:23+00:00

The CONFIG_TREE_PREEMPT_RCU and CONFIG_TINY_PREEMPT_RCU versions of
__rcu_read_lock() and __rcu_read_unlock() are identical, so this commit
consolidates them into kernel/rcupdate.h.

Signed-off-by: Paul E. McKenney 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcu: Remove return value from rcu_assign_pointer()

2012-07-02T19:34:23+00:00

The return value from rcu_assign_pointer() is not used, and using it
would be quite ugly, for example:

	q = rcu_assign_pointer(global_p, p);

To prevent this sort of ugliness from spreading, this commit wraps
rcu_assign_pointer() in a do-while loop.

Reported-by: Mathieu Desnoyers 
Reported-by: Josh Triplett 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcu: Remove return value from RCU_INIT_POINTER()

2012-07-02T19:34:23+00:00

The return value from RCU_INIT_POINTER() is not used, and using it
would be quite ugly, for example:

	q = RCU_INIT_POINTER(global_p, p);

To prevent this sort of ugliness from appearing, this commit wraps
RCU_INIT_POINTER() in a do-while loop.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Acked-by: David Howells

rcu: Add a gcc-style structure initializer for RCU pointers

2012-07-02T19:34:22+00:00

RCU_INIT_POINTER() returns a value that is never used, and which should
be abolished due to terminal ugliness:

	q = RCU_INIT_POINTER(global_p, p);

However, there are two uses that cannot be handled by a do-while
formulation because they do gcc-style initialization:

	RCU_INIT_POINTER(.real_cred, &init_cred),
	RCU_INIT_POINTER(.cred, &init_cred),

This usage is clever, but not necessarily the nicest approach.
This commit therefore creates an RCU_POINTER_INITIALIZER() macro that
is specifically designed for gcc-style initialization.

Signed-off-by: Paul E. McKenney 
Acked-by: David Howells

Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"

2012-07-02T18:39:19+00:00

This reverts commit 616c310e83b872024271c915c1b9ab505b9efad9.
(Move PREEMPT_RCU preemption to switch_to() invocation).
Testing by Sasha Levin  showed that this
can result in deadlock due to invoking the scheduler when one of
the runqueue locks is held.  Because this commit was simply a
performance optimization, revert it.

Reported-by: Sasha Levin 
Signed-off-by: Paul E. McKenney 
Tested-by: Sasha Levin