[PATCH] Avoiding mmap fragmentation

[linux-2.6] / arch / x86_64 / kernel / sys_x86_64.c

diff --git a/arch/x86_64/kernel/sys_x86_64.c b/arch/x86_64/kernel/sys_x86_64.c
index d9798dd433fca68d01f37d055df1374d28ff1353..cc7821c68851d5334b01359f8dd892a5266fdf0b 100644 (file)
--- a/arch/x86_64/kernel/sys_x86_64.c
+++ b/arch/x86_64/kernel/sys_x86_64.c
@@ -105,6 +105,11 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
                    (!vma || addr + len <= vma->vm_start))
                        return addr;
        }
+       if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32))
+           && len <= mm->cached_hole_size) {
+               mm->cached_hole_size = 0;
+               mm->free_area_cache = begin;
+       }
        addr = mm->free_area_cache;
        if (addr < begin) 
                addr = begin; 
@@ -120,6 +125,7 @@ full_search:
                         */
                        if (start_addr != begin) {
                                start_addr = addr = begin;
+                               mm->cached_hole_size = 0;
                                goto full_search;
                        }
                        return -ENOMEM;
@@ -131,6 +137,9 @@ 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;
        }
 }