Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030232AbWBMWyT (ORCPT ); Mon, 13 Feb 2006 17:54:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030229AbWBMWyT (ORCPT ); Mon, 13 Feb 2006 17:54:19 -0500 Received: from [194.90.237.34] ([194.90.237.34]:12006 "EHLO mtlexch01.mtl.com") by vger.kernel.org with ESMTP id S1030232AbWBMWyR (ORCPT ); Mon, 13 Feb 2006 17:54:17 -0500 Date: Tue, 14 Feb 2006 00:55:38 +0200 From: "Michael S. Tsirkin" To: Linus Torvalds Cc: Hugh Dickins , William Irwin , Roland Dreier , Nick Piggin , Gleb Natapov , Benjamin Herrenschmidt , Linux Kernel Mailing List , openib-general@openib.org, Petr Vandrovec , Badari Pulavarty Subject: Re: Re: madvise MADV_DONTFORK/MADV_DOFORK Message-ID: <20060213225538.GE13603@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <20060213154114.GO32041@mellanox.co.il> <20060213210906.GC13603@mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-OriginalArrivalTime: 13 Feb 2006 22:56:06.0984 (UTC) FILETIME=[AC6E6C80:01C630F0] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15450 Lines: 333 Here's the final version then. Currently, copy-on-write may change the physical address of a page even if the user requested that the page is pinned in memory (either by mlock or by get_user_pages). This happens if the process forks meanwhile, and the parent writes to that page. As a result, the page is orphaned: in case of get_user_pages, the application will never see any data hardware DMAs into this page after the COW. In particular, this affects the Infiniband modules which do DMA from and into user pages all the time. This patch adds madvise options to control whether memory range is inherited across fork. Useful e.g. for when hardware is doing DMA from/into these pages. Could also be useful to an application wanting to speed up its forks by cutting large areas out of consideration. Signed-off-by: Michael S. Tsirkin Index: linux-2.6.16-rc2/mm/madvise.c =================================================================== --- linux-2.6.16-rc2.orig/mm/madvise.c 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/mm/madvise.c 2006-02-14 03:20:33.000000000 +0200 @@ -22,16 +22,23 @@ static long madvise_behavior(struct vm_a struct mm_struct * mm = vma->vm_mm; int error = 0; pgoff_t pgoff; - int new_flags = vma->vm_flags & ~VM_READHINTMASK; + int new_flags = vma->vm_flags; switch (behavior) { + case MADV_NORMAL: + new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; + break; case MADV_SEQUENTIAL: - new_flags |= VM_SEQ_READ; + new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; break; case MADV_RANDOM: - new_flags |= VM_RAND_READ; + new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; break; - default: + case MADV_DONTFORK: + new_flags |= VM_DONTCOPY; + break; + case MADV_DOFORK: + new_flags &= ~VM_DONTCOPY; break; } @@ -177,6 +184,12 @@ madvise_vma(struct vm_area_struct *vma, long error; switch (behavior) { + case MADV_DOFORK: + if (vma->vm_flags & VM_IO) { + error = -EINVAL; + break; + } + case MADV_DONTFORK: case MADV_NORMAL: case MADV_SEQUENTIAL: case MADV_RANDOM: Index: linux-2.6.16-rc2/include/asm-x86_64/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-x86_64/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-x86_64/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -37,6 +37,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-powerpc/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-powerpc/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-powerpc/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -45,6 +45,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-cris/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-cris/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-cris/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -38,6 +38,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-arm26/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-arm26/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-arm26/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-alpha/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-alpha/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-alpha/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -43,6 +43,8 @@ #define MADV_SPACEAVAIL 5 /* ensure resources are available */ #define MADV_DONTNEED 6 /* don't need these pages */ #define MADV_REMOVE 7 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-m68k/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-m68k/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-m68k/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-xtensa/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-xtensa/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-xtensa/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -73,6 +73,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-mips/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-mips/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-mips/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -66,6 +66,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-sparc64/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-sparc64/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-sparc64/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -55,6 +55,8 @@ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_FREE 0x5 /* (Solaris) contents can be freed */ #define MADV_REMOVE 0x6 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-v850/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-v850/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-v850/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -33,6 +33,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-s390/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-s390/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-s390/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -44,6 +44,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-parisc/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-parisc/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-parisc/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -49,6 +49,8 @@ #define MADV_4M_PAGES 22 /* Use 4 Megabyte pages */ #define MADV_16M_PAGES 24 /* Use 16 Megabyte pages */ #define MADV_64M_PAGES 26 /* Use 64 Megabyte pages */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-i386/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-i386/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-i386/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-sh/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-sh/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-sh/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-ia64/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-ia64/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-ia64/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -44,6 +44,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-sparc/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-sparc/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-sparc/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -55,6 +55,8 @@ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_FREE 0x5 /* (Solaris) contents can be freed */ #define MADV_REMOVE 0x6 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-m32r/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-m32r/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-m32r/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -38,6 +38,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-frv/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-frv/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-frv/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-h8300/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-h8300/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-h8300/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS Index: linux-2.6.16-rc2/include/asm-arm/mman.h =================================================================== --- linux-2.6.16-rc2.orig/include/asm-arm/mman.h 2006-02-14 01:22:27.000000000 +0200 +++ linux-2.6.16-rc2/include/asm-arm/mman.h 2006-02-14 01:24:57.000000000 +0200 @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS -- Michael S. Tsirkin Staff Engineer, Mellanox Technologies - 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/