From 616498813b11ffefe1ed36b9f2e4fd2cdbd22f15 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 24 Apr 2013 12:58:39 +0200 Subject: s390: system call path micro optimization Add a pointer to the system call table to the thread_info structure. The TIF_31BIT bit is set or cleared by SET_PERSONALITY exactly once for the lifetime of a process. With the pointer to the correct system call table in thread_info the system call code in entry64.S path can drop the check for TIF_31BIT which saves a couple of instructions. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/thread_info.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/s390/include/asm/thread_info.h') diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index 9e2cfe0349c3..51035e5d86cb 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -41,6 +41,7 @@ struct thread_info { struct task_struct *task; /* main task structure */ struct exec_domain *exec_domain; /* execution domain */ unsigned long flags; /* low level flags */ + unsigned long sys_call_table; /* System call table address */ unsigned int cpu; /* current CPU */ int preempt_count; /* 0 => preemptable, <0 => BUG */ struct restart_block restart_block; -- cgit v1.2.3