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

From: tip-bot for Rik van Riel
Date: Thu Feb 19 2015 - 06:34:12 EST


Commit-ID: 1361ef29c7e49ae7cf37220c25fac1904b77f71a
Gitweb: http://git.kernel.org/tip/1361ef29c7e49ae7cf37220c25fac1904b77f71a
Author: Rik van Riel <riel@xxxxxxxxxx>
AuthorDate: Fri, 6 Feb 2015 15:02:03 -0500
Committer: Borislav Petkov <bp@xxxxxxx>
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@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1423252925-14451-7-git-send-email-riel@xxxxxxxxxx
[ Space out stuff for more readability. ]
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
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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