From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Fernandes Subject: Re: [PATCH v2 1/2] treewide: remove unused address argument from pte_alloc functions Date: Fri, 12 Oct 2018 09:34:33 -0700 Message-ID: <20181012163433.GA223066@joelaf.mtv.corp.google.com> References: <20181012013756.11285-1-joel@joelfernandes.org> <594fc952-5e87-3162-b2f9-963479d16eb3@kot-begemot.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <594fc952-5e87-3162-b2f9-963479d16eb3@kot-begemot.co.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane.org@lists.infradead.org List-Archive: List-Post: To: Anton Ivanov Cc: linux-mips@linux-mips.org, Rich Felker , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Dave Hansen , Will Deacon , Michal Hocko , linux-mm@kvack.org, lokeshgidra@google.com, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, elfring@users.sourceforge.net, Jonas Bonn , linux-s390@vger.kernel.org, dancol@google.com, Yoshinori Sato , Max Filippov , linux-hexagon@vger.kernel.org, Helge Deller , "maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" , hughd@google.com, "James E.J. Bottomley" , kasan-dev@googlegroups.com, kvmarm@lists.cs.columbia.edu, Ingo Molnar List-ID: On Fri, Oct 12, 2018 at 02:56:19PM +0100, Anton Ivanov wrote: > > On 10/12/18 2:37 AM, Joel Fernandes (Google) wrote: > > This series speeds up mremap(2) syscall by copying page tables at the > > PMD level even for non-THP systems. There is concern that the extra > > 'address' argument that mremap passes to pte_alloc may do something > > subtle architecture related in the future, that makes the scheme not > > work. Also we find that there is no point in passing the 'address' to > > pte_alloc since its unused. > > > > This patch therefore removes this argument tree-wide resulting in a nice > > negative diff as well. Also ensuring along the way that the architecture > > does not do anything funky with 'address' argument that goes unnoticed. > > > > Build and boot tested on x86-64. Build tested on arm64. > > > > The changes were obtained by applying the following Coccinelle script. > > The pte_fragment_alloc was manually fixed up since it was only 2 > > occurences and could not be easily generalized (and thanks Julia for > > answering all my silly and not-silly Coccinelle questions!). > > > > // Options: --include-headers --no-includes > > // Note: I split the 'identifier fn' line, so if you are manually > > // running it, please unsplit it so it runs for you. > > > > virtual patch > > > > @pte_alloc_func_def depends on patch exists@ > > identifier E2; > > identifier fn =~ > > "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; > > type T2; > > @@ > > > > fn(... > > - , T2 E2 > > ) > > { ... } > > > > @pte_alloc_func_proto depends on patch exists@ > > identifier E1, E2, E4; > > type T1, T2, T3, T4; > > identifier fn =~ > > "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; > > @@ > > > > ( > > - T3 fn(T1 E1, T2 E2); > > + T3 fn(T1 E1); > > | > > - T3 fn(T1 E1, T2 E2, T4 E4); > > + T3 fn(T1 E1, T2 E2); > > ) > > > > @pte_alloc_func_call depends on patch exists@ > > expression E2; > > identifier fn =~ > > "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; > > @@ > > > > fn(... > > -, E2 > > ) > > > > @pte_alloc_macro depends on patch exists@ > > identifier fn =~ > > "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; > > identifier a, b, c; > > expression e; > > position p; > > @@ > > > > ( > > - #define fn(a, b, c)@p e > > + #define fn(a, b) e > > | > > - #define fn(a, b)@p e > > + #define fn(a) e > > ) > > > > Suggested-by: Kirill A. Shutemov > > Cc: Michal Hocko > > Cc: Julia Lawall > > Cc: elfring@users.sourceforge.net > > Signed-off-by: Joel Fernandes (Google) > > --- > > arch/alpha/include/asm/pgalloc.h | 6 +++--- > > arch/arc/include/asm/pgalloc.h | 5 ++--- > > arch/arm/include/asm/pgalloc.h | 4 ++-- > > arch/arm64/include/asm/pgalloc.h | 4 ++-- > > arch/hexagon/include/asm/pgalloc.h | 6 ++---- > > arch/ia64/include/asm/pgalloc.h | 5 ++--- > > arch/m68k/include/asm/mcf_pgalloc.h | 8 ++------ > > arch/m68k/include/asm/motorola_pgalloc.h | 4 ++-- > > arch/m68k/include/asm/sun3_pgalloc.h | 6 ++---- > > arch/microblaze/include/asm/pgalloc.h | 19 ++----------------- > > arch/microblaze/mm/pgtable.c | 3 +-- > > arch/mips/include/asm/pgalloc.h | 6 ++---- > > arch/nds32/include/asm/pgalloc.h | 5 ++--- > > arch/nios2/include/asm/pgalloc.h | 6 ++---- > > arch/openrisc/include/asm/pgalloc.h | 5 ++--- > > arch/openrisc/mm/ioremap.c | 3 +-- > > arch/parisc/include/asm/pgalloc.h | 4 ++-- > > arch/powerpc/include/asm/book3s/32/pgalloc.h | 4 ++-- > > arch/powerpc/include/asm/book3s/64/pgalloc.h | 12 +++++------- > > arch/powerpc/include/asm/nohash/32/pgalloc.h | 4 ++-- > > arch/powerpc/include/asm/nohash/64/pgalloc.h | 6 ++---- > > arch/powerpc/mm/pgtable-book3s64.c | 2 +- > > arch/powerpc/mm/pgtable_32.c | 4 ++-- > > arch/riscv/include/asm/pgalloc.h | 6 ++---- > > arch/s390/include/asm/pgalloc.h | 4 ++-- > > arch/sh/include/asm/pgalloc.h | 6 ++---- > > arch/sparc/include/asm/pgalloc_32.h | 5 ++--- > > arch/sparc/include/asm/pgalloc_64.h | 6 ++---- > > arch/sparc/mm/init_64.c | 6 ++---- > > arch/sparc/mm/srmmu.c | 4 ++-- > > arch/um/kernel/mem.c | 4 ++-- > > There is a declaration of pte_alloc_one in arch/um/include/asm/pgalloc.h > > This patch missed it. Ah, true. Thanks. Couldn't test every arch obviously. The reason this was missed is the script could not find matches with prototypes without named parameters: extern pgtable_t pte_alloc_one(struct mm_struct *, unsigned long); I wrote something like this as below but it failed to compile, Julia any suggestions on how to express this? @pte_alloc_func_proto depends on patch exists@ type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1, T2); + T3 fn(T1); | - T3 fn(T1, T2, T4); + T3 fn(T1, T2); ) thanks, - Joel