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authorAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>2006-06-26 03:25:26 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 12:58:22 -0400
commitae9a5b85655d7133ab8e7c99b742ef20c8dbb7d2 (patch)
tree011bf055ef888a4cfb949fec467bd6385a090d12
parentb71b5b652852db1b499d22aaabed8f5043acafad (diff)
[PATCH] Notify page fault call chain for ia64
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> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/ia64/mm/fault.c36
-rw-r--r--include/asm-ia64/kdebug.h2
2 files changed, 37 insertions, 1 deletions
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index d98ec49570b8..14ef7cceb208 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -19,6 +19,40 @@
19 19
20extern void die (char *, struct pt_regs *, long); 20extern void die (char *, struct pt_regs *, long);
21 21
22#ifdef CONFIG_KPROBES
23ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
24
25/* Hook to register for page fault notifications */
26int register_page_fault_notifier(struct notifier_block *nb)
27{
28 return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
29}
30
31int unregister_page_fault_notifier(struct notifier_block *nb)
32{
33 return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
34}
35
36static inline int notify_page_fault(enum die_val val, const char *str,
37 struct pt_regs *regs, long err, int trap, int sig)
38{
39 struct die_args args = {
40 .regs = regs,
41 .str = str,
42 .err = err,
43 .trapnr = trap,
44 .signr = sig
45 };
46 return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
47}
48#else
49static inline int notify_page_fault(enum die_val val, const char *str,
50 struct pt_regs *regs, long err, int trap, int sig)
51{
52 return NOTIFY_DONE;
53}
54#endif
55
22/* 56/*
23 * Return TRUE if ADDRESS points at a page in the kernel's mapped segment 57 * Return TRUE if ADDRESS points at a page in the kernel's mapped segment
24 * (inside region 5, on ia64) and that page is present. 58 * (inside region 5, on ia64) and that page is present.
@@ -84,7 +118,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
84 /* 118 /*
85 * This is to handle the kprobes on user space access instructions 119 * This is to handle the kprobes on user space access instructions
86 */ 120 */
87 if (notify_die(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT, 121 if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
88 SIGSEGV) == NOTIFY_STOP) 122 SIGSEGV) == NOTIFY_STOP)
89 return; 123 return;
90 124
diff --git a/include/asm-ia64/kdebug.h b/include/asm-ia64/kdebug.h
index c195a9ad1255..aed7142f9e4a 100644
--- a/include/asm-ia64/kdebug.h
+++ b/include/asm-ia64/kdebug.h
@@ -40,6 +40,8 @@ struct die_args {
40 40
41extern int register_die_notifier(struct notifier_block *); 41extern int register_die_notifier(struct notifier_block *);
42extern int unregister_die_notifier(struct notifier_block *); 42extern int unregister_die_notifier(struct notifier_block *);
43extern int register_page_fault_notifier(struct notifier_block *);
44extern int unregister_page_fault_notifier(struct notifier_block *);
43extern struct atomic_notifier_head ia64die_chain; 45extern struct atomic_notifier_head ia64die_chain;
44 46
45enum die_val { 47enum die_val {