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[156.34.48.30]) by smtp.gmail.com with ESMTPSA id k185sm2269296qkd.94.2020.09.11.04.19.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2020 04:19:31 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kGh5W-004ktM-DO; Fri, 11 Sep 2020 08:19:30 -0300 Date: Fri, 11 Sep 2020 08:19:30 -0300 From: Jason Gunthorpe To: peterz@infradead.org Subject: Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding Message-ID: <20200911111930.GS87483@ziepe.ca> References: <20200909192534.442f8984@thinkpad> <20200909180324.GI87483@ziepe.ca> <20200910093925.GB29166@oc3871087118.ibm.com> <20200910181319.GO87483@ziepe.ca> <20200910211010.46d064a7@thinkpad> <20200910215921.GP87483@ziepe.ca> <20200911070939.GB1362448@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200911070939.GB1362448@hirez.programming.kicks-ass.net> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Andrey Ryabinin , Gerald Schaefer , Heiko Carstens , Arnd Bergmann , John Hubbard , Jeff Dike , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , Dave Hansen , linux-power , LKML , Andrew Morton , Linus Torvalds , Mike Rapoport Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Sep 11, 2020 at 09:09:39AM +0200, peterz@infradead.org wrote: > On Thu, Sep 10, 2020 at 06:59:21PM -0300, Jason Gunthorpe wrote: > > So, I suggest pXX_offset_unlocked() > > Urgh, no. Elsewhere in gup _unlocked() means it will take the lock > itself (get_user_pages_unlocked()) -- although often it seems to mean > the lock is already held (git grep _unlocked and marvel). > > What we want is _lockless(). This is clear to me! Thanks, Jason