|| ||"Paul E. McKenney" <email@example.com> |
|| ||firstname.lastname@example.org |
|| ||[PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of
heavy CPU-hotplug stress |
|| ||Sat, 15 Aug 2009 09:51:53 -0700|
|| ||email@example.com, firstname.lastname@example.org, email@example.com,
firstname.lastname@example.org, email@example.com, firstname.lastname@example.org,
email@example.com, firstname.lastname@example.org, email@example.com,
|| ||Article, Thread
This patch set provides the following cleanups and fixes for RCU in
workloads that involve lots of CPU hotplugging. Ingo, please reset
core/rcu to 240ebbf before applying these patches.
o Split Hierarchical RCU initialization into boot-time and
CPU-hotplug pieces, so that other CPUs never see the data
structures in the act of being stitched together.
o Introduce a cpu_notifier() that works as does the current
hotcpu_notifier(), but also notifies during boot time even
o Make RCU use the new cpu_notifier() to simplify hotplug code
and reduce the number of notifiers in use. (This also fixes
the problem Ingo and Hugh found.)
o Preemptable RCU had a bug due to its overly clever attempt
to move counts from CPUs going offline. This is "unsafe
at any speed", so remove the cleverness.
o Since offline CPUs now can have non-zero counts, they must
now be included in the tracing.
o Fix typo in preemptable RCU's rcu_irq_enter() comment
submitted by Josh Triplett.
These pass tests combining rcutorture and continuous CPU-hotplug
operations, in other words, no sleeping between successive CPU-hotplug
operations. This set does not fix the bug involving deadlocks through
rcutorture, kthread_stop(), and migration threads. However, this bug
does not affect production systems, so should not stand in the way of
applying these patches.
b/include/linux/cpu.h | 18 +++++++++-----
b/kernel/rcupdate.c | 16 ++++++++++++-
b/kernel/rcupreempt.c | 25 +-------------------
b/kernel/rcupreempt_trace.c | 6 ++--
b/kernel/rcutree.c | 54 ++++++++++++++++++++++++++------------------
kernel/rcupreempt.c | 12 +--------
kernel/rcutree.c | 18 ++++----------
7 files changed, 72 insertions(+), 77 deletions(-)
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to firstname.lastname@example.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/