Re: [PATCH] x86, math-emu: fix init_fpu for task != current

From: Ingo Molnar
Date: Wed Mar 04 2009 - 12:52:09 EST



* Daniel Glöckner <dg@xxxxxxxxx> wrote:

> On 03/02/2009 08:52 PM, Ingo Molnar wrote:
> > * Daniel Glöckner <dg@xxxxxxxxx> wrote:
> [..]
> >> This patch creates a new function finit_task that takes a task_struct
> >> parameter. finit becomes a wrapper that simply calls finit_task with
> >> current. On the plus side this avoids many calls to get_current which
> >> would each resolve to an inline assembler mov instruction.
> [..]
> >> --- a/arch/x86/kernel/i387.c
> >> +++ b/arch/x86/kernel/i387.c
> >> @@ -136,7 +136,7 @@ int init_fpu(struct task_struct *tsk)
> >> #ifdef CONFIG_X86_32
> >> if (!HAVE_HWFP) {
> >> memset(tsk->thread.xstate, 0, xstate_size);
> >> - finit();
> >> + finit_task(tsk);
> >> set_stopped_child_used_math(tsk);
> >> return 0;
> >> }
> [..]
> >
> > ok, the fix looks good - but we sure want to define this
> > function in the "# CONFIG_MATH_EMU is not set" case too, agreed?
>
> To avoid linker errors if the compiler emits the call although
> !HAVE_HWFP is always false? Sounds plausible. I also removed
> finit from i387.h as the only other external call site,
> reg_ld_str.c, gets its prototype from fpu_proto.h.

Could you please send a single combo patch with a full
changelog, etc.

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/