From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751290AbWDSWeD (ORCPT ); Wed, 19 Apr 2006 18:34:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751297AbWDSWcN (ORCPT ); Wed, 19 Apr 2006 18:32:13 -0400 Received: from mga06.intel.com ([134.134.136.21]:21341 "EHLO orsmga101.jf.intel.com") by vger.kernel.org with ESMTP id S1751290AbWDSWbr (ORCPT ); Wed, 19 Apr 2006 18:31:47 -0400 X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25199666:sNHT76902833" X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25987172:sNHT49833217" TrustExchangeSourcedMail: True X-IronPort-AV: i="4.04,137,1144047600"; d="scan'208"; a="25987145:sNHT60025868" Message-Id: <20060419221948.339390407@csdlinux-2.jf.intel.com> References: <20060419221419.382297865@csdlinux-2.jf.intel.com> Date: Wed, 19 Apr 2006 15:14:24 -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 5/7] Notify page fault call chain for sparc64 Content-Disposition: inline; filename=notify_page_fault_sparc64.patch X-OriginalArrivalTime: 19 Apr 2006 22:31:43.0295 (UTC) FILETIME=[08DAF4F0:01C66401] 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/sparc64/kernel/traps.c | 11 +++++++++++ arch/sparc64/mm/fault.c | 2 +- include/asm-sparc64/kdebug.h | 16 ++++++++++++++++ 3 files changed, 28 insertions(+), 1 deletion(-) Index: linux-2.6.17-rc1-mm3/arch/sparc64/kernel/traps.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/sparc64/kernel/traps.c +++ linux-2.6.17-rc1-mm3/arch/sparc64/kernel/traps.c @@ -44,6 +44,7 @@ #endif ATOMIC_NOTIFIER_HEAD(sparc64die_chain); +ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); int register_die_notifier(struct notifier_block *nb) { @@ -57,6 +58,16 @@ int unregister_die_notifier(struct notif } EXPORT_SYMBOL(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); +} + /* When an irrecoverable trap occurs at tl > 0, the trap entry * code logs the trap state registers at every level in the trap * stack. It is found at (pt_regs + sizeof(pt_regs)) and the layout Index: linux-2.6.17-rc1-mm3/arch/sparc64/mm/fault.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/sparc64/mm/fault.c +++ linux-2.6.17-rc1-mm3/arch/sparc64/mm/fault.c @@ -263,7 +263,7 @@ asmlinkage void __kprobes do_sparc64_fau fault_code = get_thread_fault_code(); - if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, + if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, fault_code, 0, SIGSEGV) == NOTIFY_STOP) return; Index: linux-2.6.17-rc1-mm3/include/asm-sparc64/kdebug.h =================================================================== --- linux-2.6.17-rc1-mm3.orig/include/asm-sparc64/kdebug.h +++ linux-2.6.17-rc1-mm3/include/asm-sparc64/kdebug.h @@ -17,7 +17,10 @@ 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 sparc64die_chain; +extern struct atomic_notifier_head notify_page_fault_chain; extern void bad_trap(struct pt_regs *, long); @@ -46,4 +49,17 @@ static inline int notify_die(enum die_va return atomic_notifier_call_chain(&sparc64die_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 --