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See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Ben Dooks , Peter Zijlstra , Catalin Marinas , Linus Walleij , Palmer Dabbelt , Brendan Higgins , zaslonko@linux.ibm.com, Nick Kossifidis , Alexander Potapenko , Matthew Wilcox , Mauro Carvalho Chehab , Will Deacon , Ingo Molnar , Uwe Kleine-K??nig , Bartosz Golaszewski , Masahiro Yamada , Russell King - ARM Linux , Krzysztof Kozlowski , Mike Rapoport , Christoph Hellwig , AKASHI Takahiro , Android Kernel Team , Petr Mladek , Marco Elver , Kees Cook , "Paul E. McKenney" , Mark Brown , Gregory Fong , Dan Williams , Andrew Morton , Linux ARM , Nick Desaulniers , David Gow , Randy Dunlap , "Vaittinen, Matti" , "linux-kernel@vger.kernel.org" , Palmer Dabbelt , Masami Hiramatsu , Ard Biesheuvel , David Miller Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jul 13, 2020 at 03:39:17PM +0200, Arnd Bergmann wrote: > On Mon, Jul 13, 2020 at 3:07 PM Christoph Hellwig wrote: > > On Fri, Jul 10, 2020 at 08:55:42PM -0700, Palmer Dabbelt wrote: > > > +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, > > > + size_t csize, unsigned long offset, > > > + int userbuf) > > > +{ > > > + void *vaddr; > > > + > > > + if (!csize) > > > + return 0; > > > + > > > + vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB); > > > + if (!vaddr) > > > + return -ENOMEM; > > > > Doing a memremap for every page is very inefficient. Also I don't see > > why you'd want to even do that. All memory is in the direct mapping > > for RISC-V. For other architecture that support highmem kmap_atomic_pfn > > would do the job, which is what I'd use in a generic version. > > I would expect the 'oldmem' data to not have a 'struct page', which would > be a problem at least for the generic implementation of kmap_atomic_pfn() Why do you expect it to not have a struct page? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel