linux-toradex.git/kernel/rcutorture.c, branch v2.6.25.16

cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()

2008-01-25T20:08:02+00:00

Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use
get_online_cpus and put_online_cpus instead as it highlights the
refcount semantics in these operations.

The new API guarantees protection against the cpu-hotplug operation, but
it doesn't guarantee serialized access to any of the local data
structures. Hence the changes needs to be reviewed.

In case of pseries_add_processor/pseries_remove_processor, use
cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the
cpu_present_map there.

Signed-off-by: Gautham R Shenoy 
Signed-off-by: Ingo Molnar

Make rcutorture RNG use temporal entropy

2007-10-17T15:42:53+00:00

Repost of http://lkml.org/lkml/2007/8/10/472 made available by request.

The locking used by get_random_bytes() can conflict with the
preempt_disable() and synchronize_sched() form of RCU.  This patch changes
rcutorture's RNG to gather entropy from the new cpu_clock() interface
(relying on interrupts, preemption, daemons, and rcutorture's reader
thread's rock-bottom scheduling priority to provide useful entropy), and
also adds and EXPORT_SYMBOL_GPL() to make that interface available to GPLed
kernel modules such as rcutorture.

Passes several hours of rcutorture.

[ego@in.ibm.com: Use raw_smp_processor_id() in rcu_random()]
Signed-off-by: Paul E. McKenney 
Cc: Ingo Molnar 
Signed-off-by: Gautham R Shenoy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Clean up duplicate includes in kernel/

2007-10-17T15:42:48+00:00

This patch cleans up duplicate includes in
	kernel/

Signed-off-by: Jesper Juhl 
Acked-by: Paul E. McKenney 
Reviewed-by: Satyam Sharma 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Freezer: make kernel threads nonfreezable by default

2007-07-17T17:23:02+00:00

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki 
Acked-by: Nigel Cunningham 
Cc: Pavel Machek 
Cc: Oleg Nesterov 
Cc: Gautham R Shenoy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rcutorture: Remove redundant assignment to cur_ops in for loop

2007-05-08T18:15:17+00:00

The for loop in rcutorture_init uses the condition
cur_ops = torture_ops[i], cur_ops
but then makes the same assignment to cur_ops inside the loop.  Remove the
redundant assignment inside the loop, and remove now-unnecessary braces.

Signed-off-by: Josh Triplett 
Cc: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rcutorture: style cleanup: avoid != NULL in boolean tests

2007-05-08T18:15:17+00:00

Signed-off-by: Josh Triplett 
Cc: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rcutorture: Use ARRAY_SIZE macro when appropriate

2007-05-08T18:15:17+00:00

Use ARRAY_SIZE macro already defined in kernel.h

Signed-off-by: Ahmed S. Darwish 
Cc: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rcutorture: Mark rcu_torture_init as __init

2007-05-08T18:15:00+00:00

The corresponding rcu_torture_cleanup cannot get marked as __exit, because
rcu_torture_init uses it to clean up if init fails.

Signed-off-by: Josh Triplett 
Acked-by: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Publish rcutorture module parameters via sysfs, read-only

2007-03-06T17:30:25+00:00

rcutorture's module parameters currently use permissions of 0, so they
don't show up in /sys/module/rcutorture/parameters.  Change the permissions
on all module parameters to world-readable (0444).

rcutorture does all of its initialization and thread startup when loaded
and relies on the parameters not changing during execution, so they should
not permit writing.  However, reading seems fine.

Signed-off-by: Josh Triplett 
Cc: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] rcu: rcutorture suspend fix

2006-12-30T18:55:55+00:00

Fix suspend hang: rcutorture threads need to be nofreeze.

Signed-off-by: Ingo Molnar 
Acked-by: Paul E. McKenney 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds