From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752342AbbCKRhY (ORCPT ); Wed, 11 Mar 2015 13:37:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56299 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752129AbbCKRhT (ORCPT ); Wed, 11 Mar 2015 13:37:19 -0400 Date: Wed, 11 Mar 2015 18:35:07 +0100 From: Oleg Nesterov To: Dave Hansen , Borislav Petkov , Ingo Molnar Cc: Andy Lutomirski , Linus Torvalds , Pekka Riikonen , Rik van Riel , Suresh Siddha , LKML , "Yu, Fenghua" , Quentin Casasnovas Subject: [PATCH 4/4] x86/fpu: don't abuse drop_init_fpu() in flush_thread() Message-ID: <20150311173507.GF5032@redhat.com> References: <54F74F59.5070107@intel.com> <20150311173346.GB5032@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150311173346.GB5032@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org drop_init_fpu() makes no sense. We need drop_fpu() and only if !use_eager_fpu(). Signed-off-by: Oleg Nesterov --- arch/x86/kernel/process.c | 11 ++++------- 1 files changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c396de2..2e71120 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -131,14 +131,11 @@ void flush_thread(void) flush_ptrace_hw_breakpoint(tsk); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); - drop_init_fpu(tsk); - /* - * Free the FPU state for non xsave platforms. They get reallocated - * lazily at the first use. - */ - if (!use_eager_fpu()) + if (!use_eager_fpu()) { + /* FPU state will be reallocated lazily at the first use. */ + drop_fpu(tsk); free_thread_xstate(tsk); - else if (!used_math()) { + } else if (!used_math()) { /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(init_fpu(current))) force_sig(SIGKILL, current); -- 1.5.5.1