From b716ad953a2bc4a543143c1d9836b7007a4b182f Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Date: Wed, 21 Mar 2012 16:33:56 -0700
Subject: [PATCH] mm: search from free_area_cache for the bigger size
If the required size is bigger than cached_hole_size it is better to
search from free_area_cache - it is easier to get a free region,
specifically for the 64 bit process whose address space is large enough
Do it just as hugetlb_get_unmapped_area_topdown() in arch/x86/mm/hugetlbpage.c
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/x86/kernel/sys_x86_64.c | 34 +++++++++++++++++-----------------
mm/mmap.c | 36 +++++++++++++++++++++---------------
2 files changed, 38 insertions(+), 32 deletions(-)
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 051489082d591..ef59642ff1bf9 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -195,7 +195,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
- unsigned long addr = addr0;
+ unsigned long addr = addr0, start_addr;
/* requested length too big for entire address space */
if (len > TASK_SIZE)
@@ -223,25 +223,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
mm->free_area_cache = mm->mmap_base;
}
+try_again:
/* either no address requested or can't fit in requested address hole */
- addr = mm->free_area_cache;
-
- /* make sure it can fit in the remaining address space */
- if (addr > len) {
- unsigned long tmp_addr = align_addr(addr - len, filp,
- ALIGN_TOPDOWN);
-
- vma = find_vma(mm, tmp_addr);
- if (!vma || tmp_addr + len <= vma->vm_start)
- /* remember the address as a hint for next time */
- return mm->free_area_cache = tmp_addr;
- }
-
- if (mm->mmap_base < len)
- goto bottomup;
+ start_addr = addr = mm->free_area_cache;
- addr = mm->mmap_base-len;
+ if (addr < len)
+ goto fail;
+ addr -= len;
do {
addr = align_addr(addr, filp, ALIGN_TOPDOWN);
@@ -263,6 +252,17 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
addr = vma->vm_start-len;
} while (len < vma->vm_start);
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ */
+ if (start_addr != mm->mmap_base) {
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = 0;
+ goto try_again;
+ }
+
bottomup:
/*
* A failed mmap() very likely causes application failure,
diff --git a/mm/mmap.c b/mm/mmap.c
index 4f31764d838f4..9e0c0de2e7e38 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1442,7 +1442,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
- unsigned long addr = addr0;
+ unsigned long addr = addr0, start_addr;
/* requested length too big for entire address space */
if (len > TASK_SIZE)
@@ -1466,22 +1466,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
mm->free_area_cache = mm->mmap_base;
}
+try_again:
/* either no address requested or can't fit in requested address hole */
- addr = mm->free_area_cache;
+ start_addr = addr = mm->free_area_cache;
- /* make sure it can fit in the remaining address space */
- if (addr > len) {
- vma = find_vma(mm, addr-len);
- if (!vma || addr <= vma->vm_start)
- /* remember the address as a hint for next time */
- return (mm->free_area_cache = addr-len);
- }
-
- if (mm->mmap_base < len)
- goto bottomup;
-
- addr = mm->mmap_base-len;
+ if (addr < len)
+ goto fail;
+ addr -= len;
do {
/*
* Lookup failure means no vma is above this address,
@@ -1501,7 +1493,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
addr = vma->vm_start-len;
} while (len < vma->vm_start);
-bottomup:
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ *
+ * Note: this is different with the case of bottomup
+ * which does the fully line-search, but we use find_vma
+ * here that causes some holes skipped.
+ */
+ if (start_addr != mm->mmap_base) {
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = 0;
+ goto try_again;
+ }
+
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
--
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