[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 477d8be57d64f037178962e4c0d8a3952e3d9519..cc7821c68851d5334b01359f8dd892a5266fdf0b 100644 (file)
--- a/arch/x86_64/kernel/sys_x86_64.c
+++ b/arch/x86_64/kernel/sys_x86_64.c
@@ -68,13 +68,7 @@ out:
 static void find_start_end(unsigned long flags, unsigned long *begin,
                           unsigned long *end)
 {
-#ifdef CONFIG_IA32_EMULATION
-       if (test_thread_flag(TIF_IA32)) { 
-               *begin = TASK_UNMAPPED_32;
-               *end = IA32_PAGE_OFFSET; 
-       } else 
-#endif
-       if (flags & MAP_32BIT) { 
+       if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) {
                /* This is usually used needed to map code in small
                   model, so it needs to be in the first 31bit. Limit
                   it to that.  This means we need to move the
@@ -84,10 +78,10 @@ static void find_start_end(unsigned long flags, unsigned long *begin,
                   of playground for now. -AK */ 
                *begin = 0x40000000; 
                *end = 0x80000000;              
-       } else { 
-               *begin = TASK_UNMAPPED_64; 
+       } else {
+               *begin = TASK_UNMAPPED_BASE;
                *end = TASK_SIZE; 
-               }
+       }
 } 
 
 unsigned long
@@ -111,6 +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; 
@@ -126,6 +125,7 @@ full_search:
                         */
                        if (start_addr != begin) {
                                start_addr = addr = begin;
+                               mm->cached_hole_size = 0;
                                goto full_search;
                        }
                        return -ENOMEM;
@@ -137,6 +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;
        }
 }
@@ -152,12 +155,6 @@ asmlinkage long sys_uname(struct new_utsname __user * name)
        return err ? -EFAULT : 0;
 }
 
-asmlinkage long wrap_sys_shmat(int shmid, char __user *shmaddr, int shmflg)
-{
-       unsigned long raddr;
-       return do_shmat(shmid,shmaddr,shmflg,&raddr) ?: (long)raddr;
-}
-
 asmlinkage long sys_time64(long __user * tloc)
 {
        struct timeval now;