This short patch series fixes some issues with RCU locking in the generic perf layer.
Patch 1 fixes cgroup switching rcu issues related to the fact that perf_cgroup_sched_out() and perf_cgroup_sched_in() were missing some rcu read lock to protect the reference to the cgroup. Consequently, we moved the rcu readlock out of perf_cgroup_switch() to avoid double calls. Patch 2 reinforces the testing for the rcu locking in perf cgorup code. Either we have to hold the rcu read lock or we must have the ctx->lock which guarantees the task cannot leave the cgroup. Thanks to Peter and Eric from their suggestions on how to fix this correctly. Stephane Eranian (2): perf/core: fix RCU problem with cgroup context switching code perf/core: robustify perf_cgroup_from_task rcu checks arch/x86/kernel/cpu/perf_event_intel_cqm.c | 2 +- include/linux/perf_event.h | 6 ++++-- kernel/events/core.c | 31 ++++++++++++++++++++---------- 3 files changed, 26 insertions(+), 13 deletions(-) -- 2.5.0 -- 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/
