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[109.80.100.86]) by smtp.gmail.com with ESMTPSA id o9sm1809180wmh.3.2019.02.12.02.13.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Feb 2019 02:13:25 -0800 (PST) Date: Tue, 12 Feb 2019 11:13:16 +0100 From: Andrea Parri To: "Huang, Ying" Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , "Paul E . McKenney" , Minchan Kim , Johannes Weiner , Tim Chen , Mel Gorman , =?iso-8859-1?B?Suly9G1l?= Glisse , Michal Hocko , Andrea Arcangeli , David Rientjes , Rik van Riel , Jan Kara , Dave Jiang , Daniel Jordan Subject: Re: [PATCH -mm -V7] mm, swap: fix race between swapoff and some swap operations Message-ID: <20190212101316.GA6905@andrea> References: <20190211083846.18888-1-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190211083846.18888-1-ying.huang@intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) 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: > Alternative implementation could be replacing disable preemption with > rcu_read_lock_sched and stop_machine() with synchronize_sched(). JFYI, starting with v4.20-rc1, synchronize_rcu{,expedited}() also wait for preempt-disable sections (the intent seems to retire the RCU-sched update-side API), so that here you could instead use preempt-disable + synchronize_rcu{,expedited}(). This LWN article gives an overview of the latest RCU API/semantics changes: https://lwn.net/Articles/777036/. Andrea