[PATCH] Avoiding mmap fragmentation

[linux-2.6] / arch / arm / mm / mmap.c

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 32c4b0e35b37768f7d75fa01194f1f9c3d0baac8..3de7f84b53c25e3cdd5f8d44da252336fb55645a 100644 (file)
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -73,7 +73,12 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
                    (!vma || addr + len <= vma->vm_start))
                        return addr;
        }
-       start_addr = addr = mm->free_area_cache;
+       if (len > mm->cached_hole_size) {
+               start_addr = addr = mm->free_area_cache;
+       } else {
+               start_addr = addr = TASK_UNMAPPED_BASE;
+               mm->cached_hole_size = 0;
+       }
 
 full_search:
        if (do_align)
@@ -90,6 +95,7 @@ full_search:
                         */
                        if (start_addr != TASK_UNMAPPED_BASE) {
                                start_addr = addr = TASK_UNMAPPED_BASE;
+                               mm->cached_hole_size = 0;
                                goto full_search;
                        }
                        return -ENOMEM;
@@ -101,6 +107,8 @@ full_search:
                        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 = vma->vm_end;
                if (do_align)
                        addr = COLOUR_ALIGN(addr, pgoff);