Re: [PATCH v6 0/6] Reduce synchronize_rcu() latency(v6)

[Paul E. McKenney]

On Fri, Mar 08, 2024 at 06:34:03PM +0100, Uladzislau Rezki (Sony) wrote:
> This is v6. It is based on the Paul's "dev" branch:
> 
> HEAD: f1bfe538c7970283040a7188a291aca9f18f0c42
> 
> please note, that patches should be applied from scratch,
> i.e. the v5 has to be dropped from the "dev".
> 
> v5 -> v6:
>  - Fix a race due to realising a wait-head from the gp-kthread;
>  - Use our own private workqueue with WQ_MEM_RECLAIM to have
>    at least one execution context.
> 
> v5: https://lore.kernel.org/lkml/20240220183115.74124-1-urezki@xxxxxxxxx/
> v4: https://lore.kernel.org/lkml/ZZ2bi5iPwXLgjB-f@xxxxxxxxxx/T/
> v3: https://lore.kernel.org/lkml/cd45b0b5-f86b-43fb-a5f3-47d340cd4f9f@paulmck-laptop/T/
> v2: https://lore.kernel.org/all/20231030131254.488186-1-urezki@xxxxxxxxx/T/
> v1: https://lore.kernel.org/lkml/20231025140915.590390-1-urezki@xxxxxxxxx/T/

Queued in place of your earlier series, thank you!

Not urgent, but which rcutorture scenario should be pressed into service
testing this?

							Thanx, Paul

> Uladzislau Rezki (Sony) (6):
>   rcu: Add data structures for synchronize_rcu()
>   rcu: Reduce synchronize_rcu() latency
>   rcu: Add a trace event for synchronize_rcu_normal()
>   rcu: Support direct wake-up of synchronize_rcu() users
>   rcu: Do not release a wait-head from a GP kthread
>   rcu: Allocate WQ with WQ_MEM_RECLAIM bit set
> 
>  .../admin-guide/kernel-parameters.txt         |  14 +
>  include/trace/events/rcu.h                    |  27 ++
>  kernel/rcu/tree.c                             | 361 +++++++++++++++++-
>  kernel/rcu/tree.h                             |  20 +
>  kernel/rcu/tree_exp.h                         |   2 +-
>  5 files changed, 422 insertions(+), 2 deletions(-)
> 
> -- 
> 2.39.2
>