From: Ingo Molnar <mingo@kernel.org>
Date: Wed, 27 May 2015 10:22:29 +0000 (+0200)
Subject: x86/fpu: Optimize fpu__activate_fpstate_write()
X-Git-Tag: omap-for-v4.3/legacy-v2-signed~203^2~27
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=343763c3b0a4fa2d29f7c3ba405abf8771b90876;p=pandora-kernel.git

x86/fpu: Optimize fpu__activate_fpstate_write()

fpu__activate_fpstate_write() is used before ptrace writes to the fpstate
context. Because it expects the modified registers to be reloaded on the
nexts context switch, it's only valid to call this function for stopped
child tasks.

  - add a debugging check for this assumption

  - remove code that only runs if the current task's FPU state needs
    to be saved, which cannot occur here

  - update comments to match the implementation

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

Reading git-diff-tree failed