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[174.95.215.133]) by smtp.gmail.com with ESMTPSA id j16sm3566658qkg.26.2020.10.30.15.36.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Oct 2020 15:36:57 -0700 (PDT) Date: Fri, 30 Oct 2020 18:36:55 -0400 From: Peter Xu To: Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Andrea Arcangeli , Andrew Morton , Christoph Hellwig , Hugh Dickins , Jan Kara , Jann Horn , John Hubbard , Kirill Shutemov , Kirill Tkhai , Linux-MM , Michal Hocko , Oleg Nesterov Subject: Re: [PATCH v2 1/2] mm: reorganize internal_get_user_pages_fast() Message-ID: <20201030223655.GA6357@xz-x1> References: <0-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com> <1-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com> MIME-Version: 1.0 In-Reply-To: <1-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline 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 Fri, Oct 30, 2020 at 11:46:20AM -0300, Jason Gunthorpe wrote: > The next patch in this series makes the lockless flow a little more > complex, so move the entire block into a new function and remove a level > of indention. Tidy a bit of cruft: > > - addr is always the same as start, so use start > > - Use the modern check_add_overflow() for computing end = start + len > > - nr_pinned/pages << PAGE_SHIFT needs the LHS to be unsigned long to > avoid shift overflow, make the variables unsigned long to avoid coding > casts in both places. nr_pinned was missing its cast > > - The handling of ret and nr_pinned can be streamlined a bit > > No functional change. > > Signed-off-by: Jason Gunthorpe Sorry for a very late reply (due to other distractions): Reviewed-by: Peter Xu Thanks, -- Peter Xu