On Fri, 22 Jul 2005 at 13:27:56 +1000, Andrew Morton wrote: > Chuck Ebbert <[EMAIL PROTECTED]> wrote:
> > After: > > > > 12534 math_state_restore 130.5625 > > 8354 device_not_available 203.7561 > > ----- > > 20888 > > Next step should be to physically place math_state_restore() after > > device_not_available(). Would such a patch be accepted? (Yes it > > would be ugly and require linker script changes.) > > Depends on the benefit/ugly ratio ;) This patch (may not apply cleanly to unpatched -rc3) drops overhead a few more percent: 11835 math_state_restore 144.3293 8096 device_not_available 197.4634 ----- 19931 Most of the exception/interrupt handlers should get the same treatment but the linker script would grow. Signed-off-by: Chuck Ebbert <[EMAIL PROTECTED]> Index: 2.6.13-rc3a/arch/i386/kernel/entry.S =================================================================== --- 2.6.13-rc3a.orig/arch/i386/kernel/entry.S 2005-07-16 18:09:48.000000000 -0400 +++ 2.6.13-rc3a/arch/i386/kernel/entry.S 2005-07-22 05:19:22.000000000 -0400 @@ -469,6 +469,7 @@ pushl $do_simd_coprocessor_error jmp error_code + .section ".text.i387_1", "a" ENTRY(device_not_available) pushl $-1 # mark this as an int SAVE_ALL @@ -484,6 +485,8 @@ addl $4, %esp jmp ret_from_exception + .previous + /* * Debug traps and NMI can happen at the one SYSENTER instruction * that sets up the real kernel stack. Check here, since we can't Index: 2.6.13-rc3a/arch/i386/kernel/traps.c =================================================================== --- 2.6.13-rc3a.orig/arch/i386/kernel/traps.c 2005-07-16 18:05:40.000000000 -0400 +++ 2.6.13-rc3a/arch/i386/kernel/traps.c 2005-07-22 14:02:50.000000000 -0400 @@ -972,7 +972,8 @@ * Must be called with kernel preemption disabled (in this case, * local interrupts are disabled at the call-site in entry.S). */ -asmlinkage void math_state_restore(struct pt_regs regs) +asmlinkage void __attribute__((__section__(".text.i387_2"))) +math_state_restore(struct pt_regs regs) { struct thread_info *thread = current_thread_info(); struct task_struct *tsk = thread->task; Index: 2.6.13-rc3a/arch/i386/kernel/vmlinux.lds.S =================================================================== --- 2.6.13-rc3a.orig/arch/i386/kernel/vmlinux.lds.S 2005-07-16 18:05:39.000000000 -0400 +++ 2.6.13-rc3a/arch/i386/kernel/vmlinux.lds.S 2005-07-22 05:20:30.000000000 -0400 @@ -20,6 +20,8 @@ _text = .; /* Text and read-only data */ .text : AT(ADDR(.text) - LOAD_OFFSET) { *(.text) + *(.text.i387_1) + *(.text.i387_2) SCHED_TEXT LOCK_TEXT *(.fixup) __ Chuck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/