[IA64] fix personality(PER_LINUX32) performance issue

The patch aims to fix a performance issue for the syscall
personality(PER_LINUX32).

On IA-64 box, the syscall personality (PER_LINUX32) has poor performance
because it failed to find the Linux/x86 execution domain. Then it tried
to load the kernel module however it failed always and it used the default
execution domain PER_LINUX instead. Requesting kernel modules is very
expensive. It caused the performance issue. (see the function
lookup_exec_domain in kernel/exec_domain.c).

To resolve the issue, execution domain Linux/x86 is always registered in
initialization time for IA-64 architecture.

Signed-off-by: Xiaolan Huang <xiaolan.huang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 0 insertions, 10 deletions

diff --git a/arch/ia64/ia32/ia32_support.c b/arch/ia64/ia32/ia32_support.c
index 896b1ebbfb26..a6965ddafc46 100644
--- a/arch/ia64/ia32/ia32_support.c
+++ b/arch/ia64/ia32/ia32_support.c
@@ -15,7 +15,6 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/mm.h>
-#include <linux/personality.h>
 #include <linux/sched.h>
 
 #include <asm/intrinsics.h>
@@ -29,7 +28,6 @@
 
 extern int die_if_kernel (char *str, struct pt_regs *regs, long err);
 
-struct exec_domain ia32_exec_domain;
 struct page *ia32_shared_page[NR_CPUS];
 unsigned long *ia32_boot_gdt;
 unsigned long *cpu_gdt_table[NR_CPUS];
@@ -240,14 +238,6 @@ ia32_cpu_init (void)
 static int __init
 ia32_init (void)
 {
-	ia32_exec_domain.name = "Linux/x86";
-	ia32_exec_domain.handler = NULL;
-	ia32_exec_domain.pers_low = PER_LINUX32;
-	ia32_exec_domain.pers_high = PER_LINUX32;
-	ia32_exec_domain.signal_map = default_exec_domain.signal_map;
-	ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
-	register_exec_domain(&ia32_exec_domain);
-
 #if PAGE_SHIFT > IA32_PAGE_SHIFT
 	{
 		extern struct kmem_cache *ia64_partial_page_cachep;