On Fri, Feb 06, 2015 at 03:02:04PM -0500, r...@redhat.com wrote:
> From: Rik van Riel <r...@redhat.com>
>
> Replace magic assignments of fpu.last_cpu = ~0 with more explicit
> disable_task_lazy_fpu_restore calls.
>
> This also fixes the lazy FPU restore disabling in drop_fpu, which
> only really works when !use_eager_fpu(). This is fine for now,
> because fpu_lazy_restore() is only used when !use_eager_fpu()
> currently, but we may want to expand that.
Sorry, I can't follow here. The only non-trivial change below is in
arch_dup_task_struct(). Please clarify.
[ leaving in the rest for context ]
>
> Signed-off-by: Rik van Riel <r...@redhat.com>
> ---
> arch/x86/include/asm/fpu-internal.h | 4 ++--
> arch/x86/kernel/i387.c | 2 +-
> arch/x86/kernel/process.c | 2 +-
> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/fpu-internal.h
> b/arch/x86/include/asm/fpu-internal.h
> index 04063751ac80..06af286593d7 100644
> --- a/arch/x86/include/asm/fpu-internal.h
> +++ b/arch/x86/include/asm/fpu-internal.h
> @@ -440,7 +440,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct
> task_struct *old, struct ta
> new->thread.fpu_counter > 5);
> if (__thread_has_fpu(old)) {
> if (!__save_init_fpu(old))
> - old->thread.fpu.last_cpu = ~0;
> + task_disable_lazy_fpu_restore(old);
> else
> old->thread.fpu.last_cpu = cpu;
> old->thread.fpu.has_fpu = 0; /* But leave fpu_owner_task! */
> @@ -454,7 +454,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct
> task_struct *old, struct ta
> stts();
> } else {
> old->thread.fpu_counter = 0;
> - old->thread.fpu.last_cpu = ~0;
> + task_disable_lazy_fpu_restore(old);
> if (fpu.preload) {
> new->thread.fpu_counter++;
> if (!use_eager_fpu() && fpu_lazy_restore(new, cpu))
> diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
> index 8e070a6c30e5..8416b5f85806 100644
> --- a/arch/x86/kernel/i387.c
> +++ b/arch/x86/kernel/i387.c
> @@ -250,7 +250,7 @@ int init_fpu(struct task_struct *tsk)
> if (tsk_used_math(tsk)) {
> if (cpu_has_fpu && tsk == current)
> unlazy_fpu(tsk);
> - tsk->thread.fpu.last_cpu = ~0;
> + task_disable_lazy_fpu_restore(tsk);
> return 0;
> }
>
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index dd9a069a5ec5..83480373a642 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -68,8 +68,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct
> task_struct *src)
>
> dst->thread.fpu_counter = 0;
> dst->thread.fpu.has_fpu = 0;
> - dst->thread.fpu.last_cpu = ~0;
> dst->thread.fpu.state = NULL;
> + task_disable_lazy_fpu_restore(dst);
> if (tsk_used_math(src)) {
> int err = fpu_alloc(&dst->thread.fpu);
> if (err)
> --
> 1.9.3
>
> --
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--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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