From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755119AbbBFUCR (ORCPT ); Fri, 6 Feb 2015 15:02:17 -0500 Received: from shelob.surriel.com ([74.92.59.67]:43971 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752805AbbBFUCO (ORCPT ); Fri, 6 Feb 2015 15:02:14 -0500 From: riel@redhat.com To: oleg@redhat.com Cc: dave.hansen@linux.intel.com, sbsiddha@gmail.com, luto@amacapital.net, tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com, fenghua.yu@intel.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/8] x86,fpu: introduce task_disable_lazy_fpu_restore helper Date: Fri, 6 Feb 2015 15:02:02 -0500 Message-Id: <1423252925-14451-6-git-send-email-riel@redhat.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1423252925-14451-1-git-send-email-riel@redhat.com> References: <1423252925-14451-1-git-send-email-riel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rik van Riel Currently there are a few magic assignments sprinkled through the code that disable lazy FPU state restoring, some more effective than others, and all equally mystifying. It would be easier to have a helper to explicitly disable lazy FPU state restoring for a task. Signed-off-by: Rik van Riel --- arch/x86/include/asm/fpu-internal.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 439ac3921a1e..c1f66261ad12 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -79,6 +79,16 @@ static inline void __cpu_disable_lazy_restore(unsigned int cpu) per_cpu(fpu_owner_task, cpu) = NULL; } +/* + * Used to indicate that the FPU state in memory is newer than the FPU + * state in registers, and the FPU state should be reloaded next time the + * task is run. Only safe on the current task, or non-running tasks. + */ +static inline void task_disable_lazy_fpu_restore(struct task_struct *tsk) +{ + tsk->thread.fpu.last_cpu = ~0; +} + static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu) { return new == this_cpu_read_stable(fpu_owner_task) && -- 1.9.3