From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f172.google.com (mail-wi0-f172.google.com [209.85.212.172]) by kanga.kvack.org (Postfix) with ESMTP id 95F276B0038 for ; Mon, 13 Apr 2015 08:41:33 -0400 (EDT) Received: by widdi4 with SMTP id di4so49958615wid.0 for ; Mon, 13 Apr 2015 05:41:33 -0700 (PDT) Received: from e06smtp16.uk.ibm.com (e06smtp16.uk.ibm.com. [195.75.94.112]) by mx.google.com with ESMTPS id dj8si590100wib.80.2015.04.13.05.41.31 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 13 Apr 2015 05:41:32 -0700 (PDT) Received: from /spool/local by e06smtp16.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 13 Apr 2015 13:41:30 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id C0DEF17D8063 for ; Mon, 13 Apr 2015 13:42:02 +0100 (BST) Received: from d06av12.portsmouth.uk.ibm.com (d06av12.portsmouth.uk.ibm.com [9.149.37.247]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t3DCfR8U852308 for ; Mon, 13 Apr 2015 12:41:27 GMT Received: from d06av12.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av12.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t3DCfOFP013438 for ; Mon, 13 Apr 2015 06:41:27 -0600 Message-ID: <552BB972.3010704@linux.vnet.ibm.com> Date: Mon, 13 Apr 2015 14:41:22 +0200 From: Laurent Dufour MIME-Version: 1.0 Subject: Re: [RESEND PATCH v3 1/2] mm: Introducing arch_remap hook References: <9d827fc618a718830b2c47aa87e8be546914c897.1428916945.git.ldufour@linux.vnet.ibm.com> <20150413115811.GA12354@node.dhcp.inet.fi> In-Reply-To: <20150413115811.GA12354@node.dhcp.inet.fi> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Andrew Morton , "Kirill A. Shutemov" , Hugh Dickins , Rik van Riel , Mel Gorman , Pavel Emelyanov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Ingo Molnar , linuxppc-dev@lists.ozlabs.org, cov@codeaurora.org, criu@openvz.org On 13/04/2015 13:58, Kirill A. Shutemov wrote: > On Mon, Apr 13, 2015 at 11:56:27AM +0200, 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). >> >> The architectures which need to call this hook should define >> __HAVE_ARCH_REMAP in their asm/mmu_context.h and provide the arch_remap >> service with the following prototype: >> void arch_remap(struct mm_struct *mm, >> unsigned long old_start, unsigned long old_end, >> unsigned long new_start, unsigned long new_end); >> >> Signed-off-by: Laurent Dufour >> Reviewed-by: Ingo Molnar >> --- >> mm/mremap.c | 19 +++++++++++++------ >> 1 file changed, 13 insertions(+), 6 deletions(-) >> >> diff --git a/mm/mremap.c b/mm/mremap.c >> index 2dc44b1cb1df..009db5565893 100644 >> --- a/mm/mremap.c >> +++ b/mm/mremap.c >> @@ -25,6 +25,7 @@ >> >> #include >> #include >> +#include >> >> #include "internal.h" >> >> @@ -286,13 +287,19 @@ static unsigned long move_vma(struct vm_area_struct *vma, >> old_len = new_len; >> old_addr = new_addr; >> new_addr = -ENOMEM; >> - } else if (vma->vm_file && vma->vm_file->f_op->mremap) { >> - err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma); >> - if (err < 0) { >> - move_page_tables(new_vma, new_addr, vma, old_addr, >> - moved_len, true); >> - return err; >> + } else { >> + if (vma->vm_file && vma->vm_file->f_op->mremap) { >> + err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma); >> + if (err < 0) { >> + move_page_tables(new_vma, new_addr, vma, >> + old_addr, moved_len, true); >> + return err; >> + } >> } >> +#ifdef __HAVE_ARCH_REMAP > > It would be cleaner to provide dummy arch_remap() for !__HAVE_ARCH_REMAP > in some generic header. The idea was to not impact all the architectures as arch_unmap(), arch_dup_mmap() or arch_exit_mmap() implies. I look at the headers where such a dummy arch_remap could be put but I can't figure out one which will not impact all the architecture. What about defining a dummy service earlier in mm/remap.c in the case __HAVE_ARCH_REMAP is not defined ? Something like : #ifndef __HAVE_ARCH_REMAP static inline void void arch_remap(struct mm_struct *mm, unsigned long old_start, unsigned long old_end, unsigned long new_start, unsigned long new_end) { } #endif > > >> + arch_remap(mm, old_addr, old_addr+old_len, >> + new_addr, new_addr+new_len); > > Spaces around '+'? Nice catch ;) Thanks, Laurent. > >> +#endif >> } >> >> /* Conceal VM_ACCOUNT so old reservation is not undone */ >> -- >> 1.9.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org