提交 b716ad95 编写于 作者: X Xiao Guangrong 提交者: Linus Torvalds

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: NXiao 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 f44d2198
......@@ -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,
......
......@@ -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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