[PATCH tip/core/rcu 0/2] rcu: more review feedback

From: Paul E. McKenney
Date: Sun Sep 27 2009 - 02:49:19 EST


This patchset applies the last of the review comments:

o Whitespace fixes, updated comments, and code movement.

o Improve an existing abstraction and introduce two additional
abstractions for traversing the rcu_node tree.

Issues remaining:

o I can force hangs given sufficient rcutorture testing in
conjunction with random CPU-hotplug operations. I am working
on a simpler interface between RCU and CPU hotplug that I
believe will clear this up.

o TREE_PREEMPT_RCU currently uses the TREE_RCU variant of
synchronize_rcu_expedited, which is wrong. I am working on
an expedited variant for TREE_PREEMPT_RCU, but will fall
back on synchronize_rcu() for the short term if it gives me
much trouble.

o The IPI hyperactivity from call_rcu() noted by Nick Piggin.
I believe I have identified a clean design for a fix for this.

o Make RCU less dependent on IPIs for forcing grace periods
(but this might be best deferred to 2.6.33).

o RCU priority boosting (2.6.33!).

o TINY_PREEMPT_RCU (2.6.33!).

o Squeeze another 400 bytes or so out of TINY_RCU (2.6.33!).
--
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/