[PATCH] x86: GDT alignment fix

Make GDT page aligned and page padded to support running inside of a
hypervisor.  This prevents false sharing of the GDT page with other hot
data, which is not allowed in Xen, and causes performance problems in
VMware.

Rather than go back to the old method of statically allocating the GDT
(which wastes unneded space for non-present CPUs), the GDT for APs is
allocated dynamically.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Zachary Amsden
2006-01-06 00:11:47 -08:00
committed by Linus Torvalds
parent 599a6e8ca4
commit 7c4cb60e5b
7 changed files with 29 additions and 17 deletions

View File

@@ -525,3 +525,5 @@ ENTRY(cpu_gdt_table)
.quad 0x0000000000000000 /* 0xf0 - unused */
.quad 0x0000000000000000 /* 0xf8 - GDT entry 31: double-fault TSS */
/* Be sure this is zeroed to avoid false validations in Xen */
.fill PAGE_SIZE_asm / 8 - GDT_ENTRIES,8,0