[tip:x86/fpu] x86/fpu: Don't allocate fpu->state for swapper/0

tip-bot for Oleg Nesterov
2015-03-23T12:22:58Z

Commit-ID: 4bd5bf8c85e6bca5be9e7c4b3d7ad1942ae323f3
Gitweb: http://git.kernel.org/tip/4bd5bf8c85e6bca5be9e7c4b3d7ad1942ae323f3
Author: Oleg Nesterov <oleg@redhat.com>
AuthorDate: Fri, 13 Mar 2015 19:27:16 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 23 Mar 2015 10:13:59 +0100

x86/fpu: Don't allocate fpu->state for swapper/0

Now that kthreads do not use FPU until they get executed, swapper/0
doesn't need to allocate fpu->state.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pekka Riikonen <priikone@iki.fi>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Link: http://lkml.kernel.org/r/20150313182716.GB8249@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/xsave.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 65c29b0..ada8df7b 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -680,8 +680,6 @@ void xsave_init(void)

static inline void __init eager_fpu_init_bp(void)
{
- current->thread.fpu.state =
- alloc_bootmem_align(xstate_size, __alignof__(struct xsave_struct));
if (!init_xstate_buf)
setup_init_fpu_buf();
}