From b3cf257623fabd8f1ee6700a6d328cc1c5da5a1d Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Sun, 9 Jul 2006 21:12:39 -0400 Subject: [PATCH] i386: use thread_info flags for debug regs and IO bitmaps Use thread info flags to track use of debug registers and IO bitmaps. - add TIF_DEBUG to track when debug registers are active - add TIF_IO_BITMAP to track when I/O bitmap is used - modify __switch_to() to use the new TIF flags Performance tested on Pentium II, ten runs of LMbench context switch benchmark (smaller is better:) before after avg 3.65 3.39 min 3.55 3.33 Signed-off-by: Stephane Eranian Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Acked-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/ptrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/i386/kernel/ptrace.c') diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index fd7eaf7866e..d3db03f4085 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -468,8 +468,11 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) for(i=0; i<4; i++) if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1) goto out_tsk; + if (data) + set_tsk_thread_flag(child, TIF_DEBUG); + else + clear_tsk_thread_flag(child, TIF_DEBUG); } - addr -= (long) &dummy->u_debugreg; addr = addr >> 2; child->thread.debugreg[addr] = data; -- cgit v1.2.3-70-g09d2