[PATCH tip/core/rcu 0/3] increase rcutorture intensity and fix acouple resulting bugs

From: Paul E. McKenney
Date: Tue Sep 08 2009 - 18:54:00 EST


This patch series increases the intensity of rcutorture testing for
TREE_PREEMPT_RCU and provides fixes for a couple resulting bugs.

o Make rcutorture's RCU read-side critical sections occasionally
spin for a few tens of milliseconds, which greatly increases
the probability that they will be preempted and that quiescent
states will be forced. Yes, this does uncover some bugs in
TREE_PREEMPT_RCU (though TREE_RCU passes with flying colors).

o Fix a bug where rnp->gpnum was not being updated. This
increases TREE_PREEMPT_RCU's reliability considerably, though
bugs still remain.

o Make the initialization of multi-node trees of rcu_node
structures unconditionally acquire rnp->lock. This simplifies
the code a bit and will make it easier to allow grace-period
initialization become preemptable, should this be needed.

Next steps include applying review comments, adding expedited grace
periods, and chasing down remaining bugs. Longer term, RCU priority
boosting.

b/kernel/rcutorture.c | 16 +++++++++-------
b/kernel/rcutree.c | 7 +++++--
kernel/rcutree.c | 42 ++++++++++++------------------------------
3 files changed, 26 insertions(+), 39 deletions(-)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/