kernel_optimize_test/arch/um/kernel/skas/exec.c
Jeff Dike a18ff1bde0 uml: speed up exec
flush_thread doesn't need to do a full page table walk in order to clear the
address space.  It knows what the end result needs to be, so it can call unmap
directly.

This results in a 10-20% speedup in an exec from bash.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:13:02 -07:00

41 lines
871 B
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "asm/current.h"
#include "asm/page.h"
#include "asm/signal.h"
#include "asm/ptrace.h"
#include "asm/uaccess.h"
#include "asm/mmu_context.h"
#include "tlb.h"
#include "skas.h"
#include "um_mmu.h"
#include "os.h"
void flush_thread_skas(void)
{
void *data = NULL;
unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
int ret;
ret = unmap(&current->mm->context.skas.id, 0, end, 1, &data);
if(ret){
printk("flush_thread_skas - clearing address space failed, "
"err = %d\n", ret);
force_sig(SIGKILL, current);
}
switch_mm_skas(&current->mm->context.skas.id);
}
void start_thread_skas(struct pt_regs *regs, unsigned long eip,
unsigned long esp)
{
set_fs(USER_DS);
PT_REGS_IP(regs) = eip;
PT_REGS_SP(regs) = esp;
}