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Shutemov" To: Wei Yang Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kirill.shutemov@linux.intel.com, yang.shi@linux.alibaba.com, alexander.duyck@gmail.com, rientjes@google.com Subject: Re: [Patch v2] mm: thp: grab the lock before manipulation defer list Message-ID: <20200113073614.jo2txcmazwlesl7b@box.shutemov.name> References: <20200109143054.13203-1-richardw.yang@linux.intel.com> <20200111000352.efy6krudecpshezh@box> <20200112022858.GA17733@richard> <20200112225718.5vqzezfclacujyx3@box> <20200113004457.GA27762@richard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200113004457.GA27762@richard> User-Agent: NeoMutt/20180716 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000006, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jan 13, 2020 at 08:44:57AM +0800, Wei Yang wrote: > >> It is possible two page in the same pgdate or memcg grab page lock > >> respectively and then access the same defer queue concurrently. > > If my understanding is correct, you agree with my statement? Which one? If the one above then no. list_empty only accesses list_head for the struct page, not the queue. -- Kirill A. Shutemov