From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752657AbbAKWHA (ORCPT ); Sun, 11 Jan 2015 17:07:00 -0500 Received: from shelob.surriel.com ([74.92.59.67]:38185 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752448AbbAKWF0 (ORCPT ); Sun, 11 Jan 2015 17:05:26 -0500 From: riel@redhat.com To: linux-kernel@vger.kernel.org Cc: mingo@redhat.com, hpa@zytor.com, matt.fleming@intel.com, bp@suse.de, oleg@redhat.com, pbonzini@redhat.com, tglx@linutronix.de, luto@amacapital.net Subject: [RFC PATCH 03/11] x86,fpu: move __thread_fpu_begin to when the task has the fpu Date: Sun, 11 Jan 2015 16:46:25 -0500 Message-Id: <1421012793-30106-4-git-send-email-riel@redhat.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1421012793-30106-1-git-send-email-riel@redhat.com> References: <1421012793-30106-1-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 Move the call to __thread_fpu_begin, which in turn calls __thread_set_has_fpu, to a spot where the task actually has the FPU. This is in preparation for the next patch. This changeset introduces an extraneous clts() call when switching from one FPU-using task to another FPU-using task in non-eager FPU switching mode. The next patch gets rid of that. Signed-off-by: Rik van Riel --- arch/x86/include/asm/fpu-internal.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 5f8f971..27556f4 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -420,7 +420,6 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc if (preload) { new->thread.fpu_counter++; set_thread_flag(TIF_LOAD_FPU); - __thread_set_has_fpu(new); prefetch(new->thread.fpu.state); } else if (!use_eager_fpu()) stts(); @@ -436,7 +435,6 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc prefetch(new->thread.fpu.state); set_thread_flag(TIF_LOAD_FPU); } - __thread_fpu_begin(new); } /* else: CR0.TS is still set from a previous FPU switch */ } @@ -451,6 +449,7 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc static inline void switch_fpu_finish(struct task_struct *new) { if (test_and_clear_thread_flag(TIF_LOAD_FPU)) { + __thread_fpu_begin(new); if (unlikely(restore_fpu_checking(new))) drop_init_fpu(new); } -- 1.9.3