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Message-Id: <1352155633-8648-10-git-send-email-walken@google.com>
Date: Mon, 5 Nov 2012 14:47:06 -0800
From: Michel Lespinasse <walken@...gle.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Rik van Riel <riel@...hat.com>,
Hugh Dickins <hughd@...gle.com>, linux-kernel@...r.kernel.org,
Russell King <linux@....linux.org.uk>,
Ralf Baechle <ralf@...ux-mips.org>,
Paul Mundt <lethal@...ux-sh.org>,
"David S. Miller" <davem@...emloft.net>,
Chris Metcalf <cmetcalf@...era.com>, x86@...nel.org,
William Irwin <wli@...omorphy.com>
Cc: linux-mm@...ck.org, linux-arm-kernel@...ts.infradead.org,
linux-mips@...ux-mips.org, linux-sh@...r.kernel.org,
sparclinux@...r.kernel.org
Subject: [PATCH 09/16] mm: use vm_unmapped_area() in hugetlbfs on i386 architecture
Update the i386 hugetlb_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.
Signed-off-by: Michel Lespinasse <walken@...gle.com>
---
arch/x86/mm/hugetlbpage.c | 130 +++++++++------------------------------------
1 files changed, 25 insertions(+), 105 deletions(-)
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 937bff5cdaa7..c00c4a4cd564 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -274,42 +274,15 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- unsigned long start_addr;
-
- if (len > mm->cached_hole_size) {
- start_addr = mm->free_area_cache;
- } else {
- start_addr = TASK_UNMAPPED_BASE;
- mm->cached_hole_size = 0;
- }
-
-full_search:
- addr = ALIGN(start_addr, huge_page_size(h));
-
- for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
- /* At this point: (!vma || addr < vma->vm_end). */
- if (TASK_SIZE - len < addr) {
- /*
- * Start a new search - just in case we missed
- * some holes.
- */
- if (start_addr != TASK_UNMAPPED_BASE) {
- start_addr = TASK_UNMAPPED_BASE;
- mm->cached_hole_size = 0;
- goto full_search;
- }
- return -ENOMEM;
- }
- if (!vma || addr + len <= vma->vm_start) {
- mm->free_area_cache = addr + len;
- return addr;
- }
- if (addr + mm->cached_hole_size < vma->vm_start)
- mm->cached_hole_size = vma->vm_start - addr;
- addr = ALIGN(vma->vm_end, huge_page_size(h));
- }
+ struct vm_unmapped_area_info info;
+
+ info.flags = 0;
+ info.length = len;
+ info.low_limit = TASK_UNMAPPED_BASE;
+ info.high_limit = TASK_SIZE;
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ return vm_unmapped_area(&info);
}
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
@@ -317,83 +290,30 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
- struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- unsigned long base = mm->mmap_base;
- unsigned long addr = addr0;
- unsigned long largest_hole = mm->cached_hole_size;
- unsigned long start_addr;
-
- /* don't allow allocations above current base */
- if (mm->free_area_cache > base)
- mm->free_area_cache = base;
-
- if (len <= largest_hole) {
- largest_hole = 0;
- mm->free_area_cache = base;
- }
-try_again:
- start_addr = mm->free_area_cache;
-
- /* make sure it can fit in the remaining address space */
- if (mm->free_area_cache < len)
- goto fail;
-
- /* either no address requested or can't fit in requested address hole */
- addr = (mm->free_area_cache - len) & huge_page_mask(h);
- do {
- /*
- * Lookup failure means no vma is above this address,
- * i.e. return with success:
- */
- vma = find_vma(mm, addr);
- if (!vma)
- return addr;
+ struct vm_unmapped_area_info info;
+ unsigned long addr;
- if (addr + len <= vma->vm_start) {
- /* remember the address as a hint for next time */
- mm->cached_hole_size = largest_hole;
- return (mm->free_area_cache = addr);
- } else if (mm->free_area_cache == vma->vm_end) {
- /* pull free_area_cache down to the first hole */
- mm->free_area_cache = vma->vm_start;
- mm->cached_hole_size = largest_hole;
- }
+ info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+ info.length = len;
+ info.low_limit = PAGE_SIZE;
+ info.high_limit = mm->mmap_base;
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ addr = vm_unmapped_area(&info);
- /* remember the largest hole we saw so far */
- if (addr + largest_hole < vma->vm_start)
- largest_hole = vma->vm_start - addr;
-
- /* try just below the current vma->vm_start */
- addr = (vma->vm_start - len) & huge_page_mask(h);
- } while (len <= vma->vm_start);
-
-fail:
- /*
- * if hint left us with no space for the requested
- * mapping then try again:
- */
- if (start_addr != base) {
- mm->free_area_cache = base;
- largest_hole = 0;
- goto try_again;
- }
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
- mm->free_area_cache = TASK_UNMAPPED_BASE;
- mm->cached_hole_size = ~0UL;
- addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
- len, pgoff, flags);
-
- /*
- * Restore the topdown base:
- */
- mm->free_area_cache = base;
- mm->cached_hole_size = ~0UL;
+ if (addr & ~PAGE_MASK) {
+ VM_BUG_ON(addr != -ENOMEM);
+ info.flags = 0;
+ info.low_limit = TASK_UNMAPPED_BASE;
+ info.high_limit = TASK_SIZE;
+ addr = vm_unmapped_area(&info);
+ }
return addr;
}
--
1.7.7.3
--
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