Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757471Ab1EZMCJ (ORCPT ); Thu, 26 May 2011 08:02:09 -0400 Received: from hera.kernel.org ([140.211.167.34]:41972 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757404Ab1EZMCH (ORCPT ); Thu, 26 May 2011 08:02:07 -0400 Date: Thu, 26 May 2011 12:01:45 GMT From: tip-bot for KOSAKI Motohiro Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, tglx@linutronix.de, kosaki.motohiro@jp.fujitsu.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, tglx@linutronix.de, kosaki.motohiro@jp.fujitsu.com, mingo@elte.hu In-Reply-To: <4DDE0B5C.9050907@jp.fujitsu.com> References: <4DDE0B5C.9050907@jp.fujitsu.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86: Move do_page_fault()'s error path under unlikely() Git-Commit-ID: b80ef10e84d85a06bcd0b3a24a752ec32d0e0e40 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 26 May 2011 12:01:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3209 Lines: 101 Commit-ID: b80ef10e84d85a06bcd0b3a24a752ec32d0e0e40 Gitweb: http://git.kernel.org/tip/b80ef10e84d85a06bcd0b3a24a752ec32d0e0e40 Author: KOSAKI Motohiro AuthorDate: Thu, 26 May 2011 17:12:12 +0900 Committer: Ingo Molnar CommitDate: Thu, 26 May 2011 13:54:03 +0200 x86: Move do_page_fault()'s error path under unlikely() Ingo suggested SIGKILL check should be moved into slowpath function. This will reduce the page fault fastpath impact of this recent commit: 37b23e0525d3: x86,mm: make pagefault killable Suggested-by: Ingo Molnar Signed-off-by: KOSAKI Motohiro Cc: kamezawa.hiroyu@jp.fujitsu.com Cc: minchan.kim@gmail.com Cc: willy@linux.intel.com Cc: Andrew Morton Cc: Linus Torvalds Link: http://lkml.kernel.org/r/4DDE0B5C.9050907@jp.fujitsu.com Signed-off-by: Ingo Molnar --- 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; } /* -- 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/