linux-kernel - [tip:x86/fpu] x86/fpu: Use an explicit if/ else in switch_fpu

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Date:	Thu, 19 Feb 2015 03:33:50 -0800
From:	tip-bot for Rik van Riel <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	bp@...e.de, riel@...hat.com, mingo@...nel.org, tglx@...utronix.de,
	hpa@...or.com, linux-kernel@...r.kernel.org, oleg@...hat.com,
	torvalds@...ux-foundation.org
Subject: [tip:x86/fpu] x86/fpu: Use an explicit if/
 else in switch_fpu_prepare()

Commit-ID:  1361ef29c7e49ae7cf37220c25fac1904b77f71a
Gitweb:     http://git.kernel.org/tip/1361ef29c7e49ae7cf37220c25fac1904b77f71a
Author:     Rik van Riel <riel@...hat.com>
AuthorDate: Fri, 6 Feb 2015 15:02:03 -0500
Committer:  Borislav Petkov <bp@...e.de>
CommitDate: Thu, 19 Feb 2015 11:15:54 +0100

x86/fpu: Use an explicit if/else in switch_fpu_prepare()

Use an explicit if/else branch after __save_init_fpu(old) in
switch_fpu_prepare(). This makes substituting the assignment with a call
in task_disable_lazy_fpu_restore() in the next patch easier to review.

Signed-off-by: Rik van Riel <riel@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Link: http://lkml.kernel.org/r/1423252925-14451-7-git-send-email-riel@redhat.com
[ Space out stuff for more readability. ]
Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/include/asm/fpu-internal.h | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 9c27f44..04c2807 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -434,13 +434,17 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
 	 * If the task has used the math, pre-load the FPU on xsave processors
 	 * or if the past 5 consecutive context-switches used math.
 	 */
-	fpu.preload = tsk_used_math(new) && (use_eager_fpu() ||
-					     new->thread.fpu_counter > 5);
+	fpu.preload = tsk_used_math(new) &&
+		      (use_eager_fpu() || new->thread.fpu_counter > 5);
+
 	if (__thread_has_fpu(old)) {
 		if (!__save_init_fpu(old))
-			cpu = ~0;
-		old->thread.fpu.last_cpu = cpu;
-		old->thread.fpu.has_fpu = 0;	/* But leave fpu_owner_task! */
+			old->thread.fpu.last_cpu = ~0;
+		else
+			old->thread.fpu.last_cpu = cpu;
+
+		/* But leave fpu_owner_task! */
+		old->thread.fpu.has_fpu = 0;
 
 		/* Don't change CR0.TS if we just switch! */
 		if (fpu.preload) {
--
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