x86/boot: re-order .init.data contributions

Putting a few bytes ahead of page tables isn't very efficient; there's
a gap almost worth a full page. To avoid re-ordering of items in the
source file, simply put the few small items in sub-section 1, for them
to end up after the page tables, followed (in the final binary) by non-
page-aligned items from other CUs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>

diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index 81473578fe84d50a8b3e3e5f62c2440ee28d931a..77bb7a9e2191a35303807c7ee341e974e9cffde8 100644 (file)
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -136,6 +136,7 @@ multiboot2_header:
 .Lno_nx_msg:   .asciz "ERR: Not an NX-capable CPU!"
 
         .section .init.data, "aw", @progbits
+        .subsection 1 /* Put data here after the page tables (in x86_64.S). */
         .align 4
 
         .word   0