Messages in this thread Patch in this message | | | Date | Wed, 19 Apr 2006 15:14:23 -0700 | From | Anil S Keshavamurthy <> | Subject | [(resend)patch 4/7] Notify page fault call chain for powerpc |
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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 <anil.s.keshavamurthy@intel.com>
--- arch/powerpc/kernel/traps.c | 11 +++++++++++ arch/powerpc/mm/fault.c | 2 +- include/asm-powerpc/kdebug.h | 9 +++++++++ 3 files changed, 21 insertions(+), 1 deletion(-)
Index: linux-2.6.17-rc1-mm3/arch/powerpc/kernel/traps.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/powerpc/kernel/traps.c +++ linux-2.6.17-rc1-mm3/arch/powerpc/kernel/traps.c @@ -75,6 +75,7 @@ EXPORT_SYMBOL(__debugger_fault_handler); #endif ATOMIC_NOTIFIER_HEAD(powerpc_die_chain); +ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); int register_die_notifier(struct notifier_block *nb) { @@ -88,6 +89,16 @@ 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); +} + /* * Trap & Exception support */ Index: linux-2.6.17-rc1-mm3/arch/powerpc/mm/fault.c =================================================================== --- linux-2.6.17-rc1-mm3.orig/arch/powerpc/mm/fault.c +++ linux-2.6.17-rc1-mm3/arch/powerpc/mm/fault.c @@ -142,7 +142,7 @@ int __kprobes do_page_fault(struct pt_re is_write = error_code & ESR_DST; #endif /* CONFIG_4xx || CONFIG_BOOKE */ - if (notify_die(DIE_PAGE_FAULT, "page_fault", regs, error_code, + if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code, 11, SIGSEGV) == NOTIFY_STOP) return 0; Index: linux-2.6.17-rc1-mm3/include/asm-powerpc/kdebug.h =================================================================== --- linux-2.6.17-rc1-mm3.orig/include/asm-powerpc/kdebug.h +++ linux-2.6.17-rc1-mm3/include/asm-powerpc/kdebug.h @@ -18,7 +18,10 @@ 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 powerpc_die_chain; +extern struct atomic_notifier_head notify_page_fault_chain; /* Grossly misnamed. */ enum die_val { @@ -36,5 +39,11 @@ static inline int notify_die(enum die_va return atomic_notifier_call_chain(&powerpc_die_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 /* __KERNEL__ */ #endif /* _ASM_POWERPC_KDEBUG_H */ -- - 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/
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