From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-x233.google.com (mail-wg0-x233.google.com [IPv6:2a00:1450:400c:c00::233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id CCD401A2B37 for ; Mon, 23 Mar 2015 19:52:16 +1100 (AEDT) Received: by wgbcc7 with SMTP id cc7so139972204wgb.0 for ; Mon, 23 Mar 2015 01:52:13 -0700 (PDT) Sender: Ingo Molnar Date: Mon, 23 Mar 2015 09:52:09 +0100 From: Ingo Molnar To: Laurent Dufour Subject: Re: [PATCH 1/2] mm: Introducing arch_remap hook Message-ID: <20150323085209.GA28965@gmail.com> References: <503499aae380db1c4673f146bcba6ad095021257.1426866405.git.ldufour@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <503499aae380db1c4673f146bcba6ad095021257.1426866405.git.ldufour@linux.vnet.ibm.com> Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, Arnd Bergmann , Jeff Dike , "H. Peter Anvin" , linux-kernel@vger.kernel.org, criu@openvz.org, linux-mm@kvack.org, Ingo Molnar , Paul Mackerras , user-mode-linux-user@lists.sourceforge.net, Richard Weinberger , Thomas Gleixner , Guan Xuetao , linuxppc-dev@lists.ozlabs.org, cov@codeaurora.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Laurent Dufour wrote: > Some architecture would like to be triggered when a memory area is moved > through the mremap system call. > > This patch is introducing a new arch_remap mm hook which is placed in the > path of mremap, and is called before the old area is unmapped (and the > arch_unmap hook is called). > > To no break the build, this patch adds the empty hook definition to the > architectures that were not using the generic hook's definition. > > Signed-off-by: Laurent Dufour > --- > arch/s390/include/asm/mmu_context.h | 6 ++++++ > arch/um/include/asm/mmu_context.h | 5 +++++ > arch/unicore32/include/asm/mmu_context.h | 6 ++++++ > arch/x86/include/asm/mmu_context.h | 6 ++++++ > include/asm-generic/mm_hooks.h | 6 ++++++ > mm/mremap.c | 9 +++++++-- > 6 files changed, 36 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h > index 8fb3802f8fad..ddd861a490ba 100644 > --- a/arch/s390/include/asm/mmu_context.h > +++ b/arch/s390/include/asm/mmu_context.h > @@ -131,4 +131,10 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, > { > } > > +static inline void arch_remap(struct mm_struct *mm, > + unsigned long old_start, unsigned long old_end, > + unsigned long new_start, unsigned long new_end) > +{ > +} > + > #endif /* __S390_MMU_CONTEXT_H */ > diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h > index 941527e507f7..f499b017c1f9 100644 > --- a/arch/um/include/asm/mmu_context.h > +++ b/arch/um/include/asm/mmu_context.h > @@ -27,6 +27,11 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, > struct vm_area_struct *vma) > { > } > +static inline void arch_remap(struct mm_struct *mm, > + unsigned long old_start, unsigned long old_end, > + unsigned long new_start, unsigned long new_end) > +{ > +} > /* > * end asm-generic/mm_hooks.h functions > */ > diff --git a/arch/unicore32/include/asm/mmu_context.h b/arch/unicore32/include/asm/mmu_context.h > index 1cb5220afaf9..39a0a553172e 100644 > --- a/arch/unicore32/include/asm/mmu_context.h > +++ b/arch/unicore32/include/asm/mmu_context.h > @@ -97,4 +97,10 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, > { > } > > +static inline void arch_remap(struct mm_struct *mm, > + unsigned long old_start, unsigned long old_end, > + unsigned long new_start, unsigned long new_end) > +{ > +} > + > #endif > diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h > index 883f6b933fa4..75cb71f4be1e 100644 > --- a/arch/x86/include/asm/mmu_context.h > +++ b/arch/x86/include/asm/mmu_context.h > @@ -172,4 +172,10 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, > mpx_notify_unmap(mm, vma, start, end); > } > > +static inline void arch_remap(struct mm_struct *mm, > + unsigned long old_start, unsigned long old_end, > + unsigned long new_start, unsigned long new_end) > +{ > +} > + > #endif /* _ASM_X86_MMU_CONTEXT_H */ So instead of spreading these empty prototypes around mmu_context.h files, why not add something like this to the PPC definition: #define __HAVE_ARCH_REMAP and define the empty prototype for everyone else? It's a bit like how the __HAVE_ARCH_PTEP_* namespace works. That should shrink this patch considerably. Thanks, Ingo