diff options
author | Stephane Eranian <eranian@hpl.hp.com> | 2006-09-26 10:52:28 +0200 |
---|---|---|
committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:28 +0200 |
commit | d3a4f48d4866b8623ca9adde8ce4e5fde979c132 (patch) | |
tree | 04413a1f18c6f49688d6008b583b20a287920a0f /arch/x86_64/kernel/ioport.c | |
parent | 2f766d16062d0147edff91be15de4a950667ca42 (diff) |
[PATCH] x86-64 TIF flags for debug regs and io bitmap in ctxsw
Hello,
Following my discussion with Andi. Here is a patch that introduces
two new TIF flags to simplify the context switch code in __switch_to().
The idea is to minimize the number of cache lines accessed in the common
case, i.e., when neither the debug registers nor the I/O bitmap are used.
This patch covers the x86-64 modifications. A patch for i386 follows.
Changelog:
- 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
<signed-off-by>: eranian@hpl.hp.com
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel/ioport.c')
-rw-r--r-- | arch/x86_64/kernel/ioport.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/ioport.c b/arch/x86_64/kernel/ioport.c index b81614970ecc..fe063d3cfe42 100644 --- a/arch/x86_64/kernel/ioport.c +++ b/arch/x86_64/kernel/ioport.c @@ -56,6 +56,7 @@ 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); } /* |