Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756625Ab1EZIMb (ORCPT ); Thu, 26 May 2011 04:12:31 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:58246 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756421Ab1EZIM2 (ORCPT ); Thu, 26 May 2011 04:12:28 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4DDE0B5C.9050907@jp.fujitsu.com> Date: Thu, 26 May 2011 17:12:12 +0900 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: mingo@elte.hu, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hpa@zytor.com, kamezawa.hiroyu@jp.fujitsu.com, minchan.kim@gmail.com, tglx@linutronix.de, willy@linux.intel.com CC: kosaki.motohiro@jp.fujitsu.com Subject: [PATCH] x86: add unlikely() to fatal signal check Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2491 Lines: 86 Ingo suggested SIGKILL check should be moved into slowpath function. It may reduce page fault fastpath impact. This patch do that. Suggested-by: Ingo Molnar Signed-off-by: KOSAKI Motohiro --- arch/x86/mm/fault.c | 35 ++++++++++++++++++++--------------- 1 files changed, 20 insertions(+), 15 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index f7a2a05..2dbf6bf 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -823,16 +823,30 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, force_sig_info_fault(SIGBUS, code, address, tsk, fault); } -static noinline void +static noinline int mm_fault_error(struct pt_regs *regs, unsigned long error_code, unsigned long address, unsigned int fault) { + /* + * Pagefault was interrupted by SIGKILL. We have no reason to + * continue pagefault. + */ + if (fatal_signal_pending(current)) { + if (!(fault & VM_FAULT_RETRY)) + up_read(¤t->mm->mmap_sem); + if (!(error_code & PF_USER)) + no_context(regs, error_code, address); + return 1; + } + if (!(fault & VM_FAULT_ERROR)) + return 0; + if (fault & VM_FAULT_OOM) { /* Kernel mode? Handle exceptions or die: */ if (!(error_code & PF_USER)) { up_read(¤t->mm->mmap_sem); no_context(regs, error_code, address); - return; + return 1; } out_of_memory(regs, error_code, address); @@ -843,6 +857,7 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, else BUG(); } + return 1; } static int spurious_fault_check(unsigned long error_code, pte_t *pte) @@ -1133,19 +1148,9 @@ good_area: */ fault = handle_mm_fault(mm, vma, address, flags); - if (unlikely(fault & VM_FAULT_ERROR)) { - mm_fault_error(regs, error_code, address, fault); - return; - } - - /* - * Pagefault was interrupted by SIGKILL. We have no reason to - * continue pagefault. - */ - if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { - if (!(error_code & PF_USER)) - no_context(regs, error_code, address); - return; + if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) { + if (mm_fault_error(regs, error_code, address, fault)) + return; } /* -- 1.7.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/