Commit 863a1609 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds

[PATCH] x86_64: flex mmap patch for x86-64

From: Arjan van de Ven <arjanv@redhat.com>

Do flex mmap for x86-64.  mmaps will grow down in the address space now
instead of up.

Patch has 2 parts; the generic strategy selection, and code to make a correct
TASK_SIZE .  the later may be fixed in your tree already in which case it's
redundant.  

Modified by AK to apply to 64bit processes too.
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 37742ed4
......@@ -2,7 +2,7 @@
# Makefile for the linux x86_64-specific parts of the memory manager.
#
obj-y := init.o fault.o ioremap.o extable.o pageattr.o
obj-y := init.o fault.o ioremap.o extable.o pageattr.o mmap.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_DISCONTIGMEM) += numa.o
obj-$(CONFIG_K8_NUMA) += k8topology.o
......
/*
* linux/arch/x86-64/mm/mmap.c
*
* flexible mmap layout support
*
* Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* Started by Ingo Molnar <mingo@elte.hu>
*/
#include <linux/personality.h>
#include <linux/mm.h>
/*
* Top of mmap area (just below the process stack).
*
* Leave an at least ~128 MB hole, 4GB for 64bit.
*/
#define MIN_GAP (test_thread_flag(TIF_IA32) ? 4UL*1024*1024*1024 : 128*1024*1024)
#define MAX_GAP (TASK_SIZE/6*5)
static inline unsigned long mmap_base(void)
{
unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
if (gap < MIN_GAP)
gap = MIN_GAP;
else if (gap > MAX_GAP)
gap = MAX_GAP;
return TASK_SIZE - (gap & PAGE_MASK);
}
static inline int mmap_is_legacy(void)
{
if (current->personality & ADDR_COMPAT_LAYOUT)
return 1;
if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
return 1;
return sysctl_legacy_va_layout;
}
/*
* This function, called very early during the creation of a new
* process VM image, sets up which VM layout function to use:
*/
void arch_pick_mmap_layout(struct mm_struct *mm)
{
/*
* Fall back to the standard layout if the personality
* bit is set, or if the expected stack growth is unlimited:
*/
if (mmap_is_legacy()) {
mm->mmap_base = TASK_UNMAPPED_BASE;
mm->get_unmapped_area = arch_get_unmapped_area;
mm->unmap_area = arch_unmap_area;
} else {
mm->mmap_base = mmap_base();
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
mm->unmap_area = arch_unmap_area_topdown;
}
}
......@@ -164,10 +164,6 @@ static inline void clear_in_cr4 (unsigned long mask)
#define MCA_bus__is_a_macro
/*
* User space process size: 512GB - 1GB (default).
*/
#define TASK_SIZE (0x0000007fc0000000UL)
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
......@@ -178,6 +174,14 @@ static inline void clear_in_cr4 (unsigned long mask)
#define TASK_UNMAPPED_BASE \
(test_thread_flag(TIF_IA32) ? TASK_UNMAPPED_32 : TASK_UNMAPPED_64)
/*
* User space process size: 512GB - 1GB (default).
*/
#define TASK_SIZE_64 (0x0000007fc0000000UL)
#define TASK_SIZE (test_thread_flag(TIF_IA32) ? IA32_PAGE_OFFSET : TASK_SIZE_64)
/*
* Size of io_bitmap.
*/
......@@ -461,4 +465,6 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
#define cache_line_size() (boot_cpu_data.x86_cache_alignment)
#define HAVE_ARCH_PICK_MMAP_LAYOUT
#endif /* __ASM_X86_64_PROCESSOR_H */
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