Messages in this thread | | | From | Frederic Weisbecker <> | Subject | [PATCH 00/11] rcu: Make rcu_core() safe in PREEMPT_RT with NOCB + a few other fixes | Date | Thu, 30 Sep 2021 00:10:01 +0200 |
| |
PREEMPT_RT has made rcu_core() preemptible, making it unsafe against concurrent NOCB (de-)offloading.
Thomas suggested to drop the local_lock() based solution and simply check the offloaded state while context looks safe but that's not enough. Here is a bit of rework.
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git rcu/rt
HEAD: aac1c58961446c731f2e989bd822ca1fd2659bad
Thanks, Frederic ---
Frederic Weisbecker (10): rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading rcu/nocb: Prepare state machine for a new step rcu/nocb: Invoke rcu_core() at the start of deoffloading rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check rcu/nocb: Use appropriate rcu_nocb_lock_irqsave() rcu/nocb: Limit number of softirq callbacks only on softirq rcu: Fix callbacks processing time limit retaining cond_resched() rcu: Apply callbacks processing time limit only on softirq rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread
Thomas Gleixner (1): rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe
include/linux/rcu_segcblist.h | 51 +++++++++++++++++++------- kernel/rcu/rcu_segcblist.c | 10 ++--- kernel/rcu/rcu_segcblist.h | 7 ++-- kernel/rcu/tree.c | 85 ++++++++++++++++++++++++++++++------------- kernel/rcu/tree.h | 16 +++++--- kernel/rcu/tree_nocb.h | 29 ++++++++++++--- 6 files changed, 136 insertions(+), 62 deletions(-)
| |