Re: [PATCH 00/10] rcu: Make rcu_core() safe in PREEMPT_RT with NOCB + a few other fixes v3

Paul E. McKenney
2021-10-19T00:16:54Z

On Tue, Oct 19, 2021 at 02:08:06AM +0200, Frederic Weisbecker wrote:
> Changes since v2:
>
> _ Drop first patch (got applied by Paul)
>
> _ Fix unwanted rcu_core() hanging around after setting a CPU as nocb
> on boot. This resulted in terrible rcu_barrier() misordering.
> I simply forgot to clear SEGCBLIST_RCU_CORE on nocb CPUs on boot.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> rcu/rt-v3
>
> HEAD: 7610a2ba5eaca8caf977ed45bad251ac693feefa

Queued for further review and testing!

Thanx, Paul

> Thanks,
> Frederic
> ---
>
> Frederic Weisbecker (9):
> 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 | 12 +++---
> kernel/rcu/tree.c | 87 +++++++++++++++++++++++++++++--------------
> kernel/rcu/tree_nocb.h | 33 ++++++++++++----
> 5 files changed, 133 insertions(+), 60 deletions(-)