The patch titled
Subject: mm: search from free_area_cache for the bigger size
has been added to the -mm tree. Its filename is
mm-search-from-free_area_cache-for-the-bigger-size.patch
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From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/sys_x86_64.c | 34 +++++++++++++++----------------
mm/mmap.c | 36 +++++++++++++++++++--------------
2 files changed, 38 insertions(+), 32 deletions(-)
diff -puN arch/x86/kernel/sys_x86_64.c~mm-search-from-free_area_cache-for-the-bigger-size arch/x86/kernel/sys_x86_64.c
--- a/arch/x86/kernel/sys_x86_64.c~mm-search-from-free_area_cache-for-the-bigger-size
+++ a/arch/x86/kernel/sys_x86_64.c
@@ -195,7 +195,7 @@ arch_get_unmapped_area_topdown(struct fi
{
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 fi
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) {
- 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;
-
- 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 fi
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 -puN mm/mmap.c~mm-search-from-free_area_cache-for-the-bigger-size mm/mmap.c
--- a/mm/mmap.c~mm-search-from-free_area_cache-for-the-bigger-size
+++ a/mm/mmap.c
@@ -1462,7 +1462,7 @@ arch_get_unmapped_area_topdown(struct fi
{
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)
@@ -1486,22 +1486,14 @@ arch_get_unmapped_area_topdown(struct fi
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,
@@ -1521,7 +1513,21 @@ arch_get_unmapped_area_topdown(struct fi
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
_
Subject: Subject: mm: search from free_area_cache for the bigger size
Patches currently in -mm which might be from xiaoguangrong@xxxxxxxxxxxxxxxxxx are
hugetlbfs-fix-hugetlb_get_unmapped_area.patch
hugetlb-drop-prev_vma-in-hugetlb_get_unmapped_area_topdown.patch
hugetlb-try-to-search-again-if-it-is-really-needed.patch
hugetlb-try-to-search-again-if-it-is-really-needed-fix.patch
mm-do-not-reset-cached_hole_size-when-vma-is-unmapped.patch
mm-search-from-free_area_cache-for-the-bigger-size.patch
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