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[94.245.46.49]) by smtp.gmail.com with ESMTPSA id k3sm608184lji.125.2020.07.15.12.36.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2020 12:36:59 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Wed, 15 Jul 2020 21:36:57 +0200 To: Sebastian Andrzej Siewior Cc: Uladzislau Rezki , LKML , RCU , linux-mm@kvack.org, "Paul E . McKenney" , Andrew Morton , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , Oleksiy Avramchenko Subject: Re: [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator Message-ID: <20200715193657.GB26938@pc636> References: <20200715183537.4010-1-urezki@gmail.com> <20200715185628.7b4k3o5efp4gnbla@linutronix.de> <20200715190243.GA26735@pc636> <20200715193250.axntj7jdt6bw52dr@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200715193250.axntj7jdt6bw52dr@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: BD2E518038E67 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jul 15, 2020 at 09:32:50PM +0200, Sebastian Andrzej Siewior wrote: > On 2020-07-15 21:02:43 [+0200], Uladzislau Rezki wrote: > > > > > > spin_lock(); > > __get_free_page(GFP_NOWAIT | __GFP_NOWARN); > > spin_unlock(); > > > > > > Also, please note we do it for regular kernel. > > ach right okay then. > > > > > > > What happened to the part where I asked for a spinlock_t? > > > > > What do you mean? > > Please drop that raw_spinlock_t for the kfree_rcu() based locking and > use just a plain spinlock_t for the locking. Then you can keep the same > code flow for RT and !RT without any special cases and everything. > Ahhh... That i see :) I guess it is up to Paul. I wrote my thoughts. I have only one concern that i explained in my previous mails. Thank you, Sebastian, for your comments! -- Vlad Rezki