From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751196AbWDSWcM (ORCPT ); Wed, 19 Apr 2006 18:32:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751294AbWDSWbu (ORCPT ); Wed, 19 Apr 2006 18:31:50 -0400 Received: from mga05.intel.com ([192.55.52.89]:54347 "EHLO fmsmga101.fm.intel.com") by vger.kernel.org with ESMTP id S1751288AbWDSWbq (ORCPT ); Wed, 19 Apr 2006 18:31:46 -0400 X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25987194:sNHT47247459" X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25987157:sNHT58002098" TrustExchangeSourcedMail: True X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25987144:sNHT55736128" Message-Id: <20060419221948.015059242@csdlinux-2.jf.intel.com> References: <20060419221419.382297865@csdlinux-2.jf.intel.com> Date: Wed, 19 Apr 2006 15:14:22 -0700 From: Anil S Keshavamurthy To: Anderw Morton Cc: LKML , Keith Owens , Dean Nelson , Tony Luck , Ananth Mavinakayanahalli , Prasanna Panchamukhi , Dave M , Andi Kleen , Robin Holt , Anil S Keshavamurthy Subject: [(resend)patch 3/7] Notify page fault call chain for ia64 Content-Disposition: inline; filename=notify_page_fault_ia64.patch X-OriginalArrivalTime: 19 Apr 2006 22:31:42.0217 (UTC) FILETIME=[08367790:01C66401] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Overloading of page fault notification with the notify_die() has performance issues(since the only interested components for page fault is kprobes and/or kdb) and hence this patch introduces the new notifier call chain exclusively for page fault notifications their by avoiding notifying unnecessary components in the do_page_fault() code path. Signed-off-by: Anil S Keshavamurthy --- arch/ia64/kernel/traps.c | 11 +++++++++++ arch/ia64/mm/fault.c | 2 +- include/asm-ia64/kdebug.h | 16 ++++++++++++++++ 3 files changed, 28 insertions(+), 1 deletion(-) Index: linux-2.6.17-rc1-mm3/arch/ia64/kernel/traps.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/ia64/kernel/traps.c +++ linux-2.6.17-rc1-mm3/arch/ia64/kernel/traps.c @@ -31,6 +31,7 @@ fpswa_interface_t *fpswa_interface; EXPORT_SYMBOL(fpswa_interface); ATOMIC_NOTIFIER_HEAD(ia64die_chain); +ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); int register_die_notifier(struct notifier_block *nb) @@ -46,6 +47,16 @@ unregister_die_notifier(struct notifier_ } EXPORT_SYMBOL_GPL(unregister_die_notifier); +int register_page_fault_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(¬ify_page_fault_chain, nb); +} + +int unregister_page_fault_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb); +} + void __init trap_init (void) { Index: linux-2.6.17-rc1-mm3/arch/ia64/mm/fault.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/ia64/mm/fault.c +++ linux-2.6.17-rc1-mm3/arch/ia64/mm/fault.c @@ -84,7 +84,7 @@ ia64_do_page_fault (unsigned long addres /* * This is to handle the kprobes on user space access instructions */ - if (notify_die(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT, + if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT, SIGSEGV) == NOTIFY_STOP) return; Index: linux-2.6.17-rc1-mm3/include/asm-ia64/kdebug.h =================================================================== --- linux-2.6.17-rc1-mm3.orig/include/asm-ia64/kdebug.h +++ linux-2.6.17-rc1-mm3/include/asm-ia64/kdebug.h @@ -40,7 +40,10 @@ struct die_args { extern int register_die_notifier(struct notifier_block *); extern int unregister_die_notifier(struct notifier_block *); +extern int register_page_fault_notifier(struct notifier_block *); +extern int unregister_page_fault_notifier(struct notifier_block *); extern struct atomic_notifier_head ia64die_chain; +extern struct atomic_notifier_head notify_page_fault_chain; enum die_val { DIE_BREAK = 1, @@ -86,4 +89,17 @@ static inline int notify_die(enum die_va return atomic_notifier_call_chain(&ia64die_chain, val, &args); } +static inline int notify_page_fault(enum die_val val, char *str, struct pt_regs *regs, + long err, int trap, int sig) +{ + struct die_args args = { + .regs = regs, + .str = str, + .err = err, + .trapnr = trap, + .signr = sig + }; + + return atomic_notifier_call_chain(¬ify_page_fault_chain, val, &args); +} #endif --