madvise MADV_DONTFORK/MADV_DOFORK
From: Michael S. Tsirkin
Date: Mon Feb 13 2006 - 10:37:55 EST
OK, I guess its time to start the push for merging this patch.
Probably not 2.6.16 material, but it would be nice to get this say into -mm to
make it easier to test this. Tested on x86_64 only.
Please Cc me directly with comments, I'm not on the list.
---
Add madvise options to control whether memory range is inherited across fork.
Useful e.g. for when hardware is doing DMA from/into these pages.
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxxxxxx>
Index: linux-2.6.16-rc2/kernel/fork.c
===================================================================
--- linux-2.6.16-rc2.orig/kernel/fork.c 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/kernel/fork.c 2006-02-12 20:48:37.000000000 +0200
@@ -210,7 +210,7 @@ static inline int dup_mmap(struct mm_str
for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
struct file *file;
- if (mpnt->vm_flags & VM_DONTCOPY) {
+ if (mpnt->vm_flags & (VM_DONTCOPY | VM_DONTFORK)) {
long pages = vma_pages(mpnt);
mm->total_vm -= pages;
vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
Index: linux-2.6.16-rc2/mm/mmap.c
===================================================================
--- linux-2.6.16-rc2.orig/mm/mmap.c 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/mm/mmap.c 2006-02-12 20:48:37.000000000 +0200
@@ -847,7 +847,7 @@ void vm_stat_account(struct mm_struct *m
#ifdef CONFIG_HUGETLB
if (flags & VM_HUGETLB) {
- if (!(flags & VM_DONTCOPY))
+ if (!(flags & (VM_DONTCOPY|VM_DONTFORK)))
mm->shared_vm += pages;
return;
}
Index: linux-2.6.16-rc2/mm/madvise.c
===================================================================
--- linux-2.6.16-rc2.orig/mm/madvise.c 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/mm/madvise.c 2006-02-12 20:48:37.000000000 +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_DONTFORK;
+ break;
+ case MADV_DOFORK:
+ new_flags &= ~VM_DONTFORK;
break;
}
@@ -180,6 +187,8 @@ madvise_vma(struct vm_area_struct *vma,
case MADV_NORMAL:
case MADV_SEQUENTIAL:
case MADV_RANDOM:
+ case MADV_DONTFORK:
+ case MADV_DOFORK:
error = madvise_behavior(vma, prev, start, end, behavior);
break;
case MADV_REMOVE:
Index: linux-2.6.16-rc2/include/linux/mm.h
===================================================================
--- linux-2.6.16-rc2.orig/include/linux/mm.h 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/include/linux/mm.h 2006-02-12 20:52:11.000000000 +0200
@@ -166,6 +166,7 @@ extern unsigned int kobjsize(const void
#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
+#define VM_DONTFORK 0x04000000 /* App wants to avoid inheriting the vma on fork */
#ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
Index: linux-2.6.16-rc2/include/asm-x86_64/mman.h
===================================================================
--- linux-2.6.16-rc2.orig/include/asm-x86_64/mman.h 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-x86_64/mman.h 2006-02-12 20:52:21.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-powerpc/mman.h 2006-02-12 20:55:07.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-cris/mman.h 2006-02-12 20:54:31.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-arm26/mman.h 2006-02-12 20:54:27.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-alpha/mman.h 2006-02-12 20:55:44.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-m68k/mman.h 2006-02-12 20:54:54.000000000 +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 2006-02-10 03:43:19.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-xtensa/mman.h 2006-02-12 20:55:38.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-mips/mman.h 2006-02-12 20:55:00.000000000 +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 2006-02-10 03:43:18.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-sparc64/mman.h 2006-02-12 20:55:24.000000000 +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 2006-02-10 03:43:18.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-v850/mman.h 2006-02-12 20:55:31.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-s390/mman.h 2006-02-12 20:55:11.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-parisc/mman.h 2006-02-12 20:55:04.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-i386/mman.h 2006-02-12 20:54:43.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-sh/mman.h 2006-02-12 20:55:14.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-ia64/mman.h 2006-02-12 20:54:47.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-sparc/mman.h 2006-02-12 20:55:20.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-m32r/mman.h 2006-02-12 20:54:51.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-frv/mman.h 2006-02-12 20:54:35.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-h8300/mman.h 2006-02-12 20:54:39.000000000 +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 2006-02-10 03:43:13.000000000 +0200
+++ linux-2.6.16-rc2/include/asm-arm/mman.h 2006-02-12 20:54:19.000000000 +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
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