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McKenney" To: "Uladzislau Rezki (Sony)" Cc: LKML , RCU , linux-mm@kvack.org, Andrew Morton , Peter Zijlstra , Michal Hocko , Vlastimil Babka , Thomas Gleixner , "Theodore Y . Ts'o" , Joel Fernandes , Sebastian Andrzej Siewior , Oleksiy Avramchenko Subject: Re: [PATCH 0/4] kvfree_rcu() and _LOCK_NESTING/_PREEMPT_RT Message-ID: <20200918221528.GX29330@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200918194817.48921-1-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200918194817.48921-1-urezki@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 18, 2020 at 09:48:13PM +0200, Uladzislau Rezki (Sony) wrote: > Hello, folk! > > This is another iteration of fixing kvfree_rcu() issues related > to CONFIG_PROVE_RAW_LOCK_NESTING and CONFIG_PREEMPT_RT configs. > > The first discussion is here https://lkml.org/lkml/2020/8/9/195. > > - As an outcome of it, there was a proposal from Peter, instead of > using a speciall "lock-less" flag it is better to move lock-less > access to the pcplist to the separate function. > > - To add a special worker thread that does prefetching of pages > if a per-cpu page cache is depleted(what is absolutely normal). > > As usual, thank you for paying attention to it and your help! > > Uladzislau Rezki (Sony) (4): > rcu/tree: Add a work to allocate pages from regular context > mm: Add __rcu_alloc_page_lockless() func. > rcu/tree: use __rcu_alloc_page_lockless() func. > rcu/tree: Use schedule_delayed_work() instead of WQ_HIGHPRI queue Thank you, Uladzislau! I have pulled this into -rcu for review and testing. I have not yet assigned it to an intended release. Thanx, Paul > include/linux/gfp.h | 1 + > kernel/rcu/tree.c | 90 ++++++++++++++++++++++++--------------------- > mm/page_alloc.c | 82 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 132 insertions(+), 41 deletions(-) > > -- > 2.20.1 >