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/ioport.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/i386/kernel/ioport.c') diff --git a/arch/i386/kernel/ioport.c b/arch/i386/kernel/ioport.c index 79026f026b85..498e8bc197d5 100644 --- a/arch/i386/kernel/ioport.c +++ b/arch/i386/kernel/ioport.c @@ -79,6 +79,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on) memset(bitmap, 0xff, IO_BITMAP_BYTES); t->io_bitmap_ptr = bitmap; + set_thread_flag(TIF_IO_BITMAP); } /* -- cgit v1.2.1