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/ia32 | |
| 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/ia32')
| -rw-r--r-- | arch/x86_64/ia32/ptrace32.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86_64/ia32/ptrace32.c b/arch/x86_64/ia32/ptrace32.c index 659c0722f6b8..72bf92a9d375 100644 --- a/arch/x86_64/ia32/ptrace32.c +++ b/arch/x86_64/ia32/ptrace32.c @@ -117,6 +117,10 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val) if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1) return -EIO; child->thread.debugreg7 = val; + if (val) + set_tsk_thread_flag(child, TIF_DEBUG); + else + clear_tsk_thread_flag(child, TIF_DEBUG); break; default: |