powerpc: Move 64bit VDSO to improve context switch performance

[safe/jmp/linux-2.6] / arch / powerpc / kernel / vdso.c

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index ad06d5c..a0abce2 100644 (file)
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -203,7 +203,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
        } else {
                vdso_pagelist = vdso64_pagelist;
                vdso_pages = vdso64_pages;
-               vdso_base = VDSO64_MBASE;
+               /*
+                * On 64bit we don't have a preferred map address. This
+                * allows get_unmapped_area to find an area near other mmaps
+                * and most likely share a SLB entry.
+                */
+               vdso_base = 0;
        }
 #else
        vdso_pagelist = vdso32_pagelist;