[PATCH v2] perf, x86-mm: declare page-faults tracepoints like irq-vectors ones

From: Alexis Berlemont
Date: Thu Oct 27 2016 - 19:35:50 EST


The tracepoints "exceptions:page_fault_(user|kernel)" were renamed
"exceptions:page_fault_(user|kernel)_entry". Two more tracepoints were
added: "exceptions:page_fault_(user|kernel)_exit". These events are
called right before and after __do_page_fault().

Signed-off-by: Alexis Berlemont <alexis.berlemont@xxxxxxxxx>
---
arch/x86/include/asm/trace/exceptions.h | 17 ++++++++++++++++-
arch/x86/mm/fault.c | 17 ++++++++++++++---
2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/trace/exceptions.h b/arch/x86/include/asm/trace/exceptions.h
index 2fbc66c..ecbe64e 100644
--- a/arch/x86/include/asm/trace/exceptions.h
+++ b/arch/x86/include/asm/trace/exceptions.h
@@ -33,14 +33,29 @@ DECLARE_EVENT_CLASS(x86_exceptions,
__entry->error_code) );

#define DEFINE_PAGE_FAULT_EVENT(name) \
-DEFINE_EVENT_FN(x86_exceptions, name, \
+DEFINE_EVENT_FN(x86_exceptions, name##_entry, \
+ TP_PROTO(unsigned long address, struct pt_regs *regs, \
+ unsigned long error_code), \
+ TP_ARGS(address, regs, error_code), \
+ trace_irq_vector_regfunc, \
+ trace_irq_vector_unregfunc); \
+DEFINE_EVENT_FN(x86_exceptions, name##_exit, \
TP_PROTO(unsigned long address, struct pt_regs *regs, \
unsigned long error_code), \
TP_ARGS(address, regs, error_code), \
trace_irq_vector_regfunc, \
trace_irq_vector_unregfunc);

+/*
+ * page_fault_user - called when entering/exiting a page fault in
+ * user-space
+ */
DEFINE_PAGE_FAULT_EVENT(page_fault_user);
+
+/*
+ * page_fault_kernel - called when entering/exiting a page fault in
+ * kernel-space
+ */
DEFINE_PAGE_FAULT_EVENT(page_fault_kernel);

#undef TRACE_INCLUDE_PATH
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9f72ca3..2ed2716 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1465,12 +1465,22 @@ NOKPROBE_SYMBOL(do_page_fault);
#ifdef CONFIG_TRACING
static nokprobe_inline void
trace_page_fault_entries(unsigned long address, struct pt_regs *regs,
- unsigned long error_code)
+ unsigned long error_code)
{
if (user_mode(regs))
- trace_page_fault_user(address, regs, error_code);
+ trace_page_fault_user_entry(address, regs, error_code);
else
- trace_page_fault_kernel(address, regs, error_code);
+ trace_page_fault_kernel_entry(address, regs, error_code);
+}
+
+static nokprobe_inline void
+trace_page_fault_exits(unsigned long address, struct pt_regs *regs,
+ unsigned long error_code)
+{
+ if (user_mode(regs))
+ trace_page_fault_user_exit(address, regs, error_code);
+ else
+ trace_page_fault_kernel_exit(address, regs, error_code);
}

dotraplinkage void notrace
@@ -1488,6 +1498,7 @@ trace_do_page_fault(struct pt_regs *regs, unsigned long error_code)
prev_state = exception_enter();
trace_page_fault_entries(address, regs, error_code);
__do_page_fault(regs, error_code, address);
+ trace_page_fault_exits(address, regs, error_code);
exception_exit(prev_state);
}
NOKPROBE_SYMBOL(trace_do_page_fault);
--
2.10.1