Hello, Ingo, This series fixes some RCU regressions in 3.7.
Kirill A. Shutemov found a case where synchronize_rcu() is invoked from a CPU-hotplug notifier, which, with RCU's shiny new kthread-based grace-period implementation, results in deadlock. The first commit in this series fixes this deadlock by introducing RCU-specific synchronization, so that RCU grace periods exclude only RCU's CPU-hotplug notifiers, not the entire CPU-hotplug operation. Kirill successfully tested this commit (as have I), and it has furthermore been exposed to -next testing. The other commit in this series adds a warning to the new RCU_USER_QS and RCU_USER_QS_FORCE Kconfig options, noting that these features, though reasonably stable, are probably not ready for millions of users. This commit affects only the Kconfig help text. These changes are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/urgent Thanx, Paul ------------------> Frederic Weisbecker (1): rcu: Advise most users not to enable RCU user mode Paul E. McKenney (1): rcu: Grace-period initialization excludes only RCU notifier init/Kconfig | 12 ++++++++++++ kernel/rcutree.c | 21 ++++++++++----------- kernel/rcutree.h | 6 ++++++ 3 files changed, 28 insertions(+), 11 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/