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authorIngo Molnar <mingo@elte.hu>2010-02-26 09:20:17 +0100
committerIngo Molnar <mingo@elte.hu>2010-02-26 09:20:17 +0100
commit281b3714e91162b66add1cfac404cf7b81e3e2f2 (patch)
tree9f80453153db272c207129d971e17d31a6bb214a
parent64b9fb5704a479d98a59f2a1d45d3331a8f847f8 (diff)
parent7b60997f73865b019e595720185c85285ca3df9a (diff)
downloadlinux-linaro-281b3714e91162b66add1cfac404cf7b81e3e2f2.tar.gz
Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core
-rw-r--r--arch/x86/kernel/ftrace.c26
-rw-r--r--include/linux/syscalls.h6
-rw-r--r--include/trace/ftrace.h3
-rw-r--r--kernel/trace/Kconfig9
-rw-r--r--kernel/trace/trace.h3
-rw-r--r--kernel/trace/trace_events.c4
-rw-r--r--kernel/trace/trace_functions_graph.c1
-rw-r--r--kernel/trace/trace_kprobe.c4
-rw-r--r--kernel/trace/trace_syscalls.c2
9 files changed, 38 insertions, 20 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 30968924543..605ef196fdd 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -30,14 +30,32 @@
#ifdef CONFIG_DYNAMIC_FTRACE
+/*
+ * modifying_code is set to notify NMIs that they need to use
+ * memory barriers when entering or exiting. But we don't want
+ * to burden NMIs with unnecessary memory barriers when code
+ * modification is not being done (which is most of the time).
+ *
+ * A mutex is already held when ftrace_arch_code_modify_prepare
+ * and post_process are called. No locks need to be taken here.
+ *
+ * Stop machine will make sure currently running NMIs are done
+ * and new NMIs will see the updated variable before we need
+ * to worry about NMIs doing memory barriers.
+ */
+static int modifying_code __read_mostly;
+static DEFINE_PER_CPU(int, save_modifying_code);
+
int ftrace_arch_code_modify_prepare(void)
{
set_kernel_text_rw();
+ modifying_code = 1;
return 0;
}
int ftrace_arch_code_modify_post_process(void)
{
+ modifying_code = 0;
set_kernel_text_ro();
return 0;
}
@@ -149,6 +167,11 @@ static void ftrace_mod_code(void)
void ftrace_nmi_enter(void)
{
+ __get_cpu_var(save_modifying_code) = modifying_code;
+
+ if (!__get_cpu_var(save_modifying_code))
+ return;
+
if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
smp_rmb();
ftrace_mod_code();
@@ -160,6 +183,9 @@ void ftrace_nmi_enter(void)
void ftrace_nmi_exit(void)
{
+ if (!__get_cpu_var(save_modifying_code))
+ return;
+
/* Finish all executions before clearing nmi_running */
smp_mb();
atomic_dec(&nmi_running);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 7b219696ad2..91bd7d78a07 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -132,7 +132,8 @@ struct perf_event_attr;
#define SYSCALL_TRACE_ENTER_EVENT(sname) \
static const struct syscall_metadata __syscall_meta_##sname; \
- static struct ftrace_event_call event_enter_##sname; \
+ static struct ftrace_event_call \
+ __attribute__((__aligned__(4))) event_enter_##sname; \
static struct trace_event enter_syscall_print_##sname = { \
.trace = print_syscall_enter, \
}; \
@@ -153,7 +154,8 @@ struct perf_event_attr;
#define SYSCALL_TRACE_EXIT_EVENT(sname) \
static const struct syscall_metadata __syscall_meta_##sname; \
- static struct ftrace_event_call event_exit_##sname; \
+ static struct ftrace_event_call \
+ __attribute__((__aligned__(4))) event_exit_##sname; \
static struct trace_event exit_syscall_print_##sname = { \
.trace = print_syscall_exit, \
}; \
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 09fd9afc085..f23a0ca6910 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -65,7 +65,8 @@
};
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
- static struct ftrace_event_call event_##name
+ static struct ftrace_event_call \
+ __attribute__((__aligned__(4))) event_##name
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 60e2ce0181e..e6b99b8c3d3 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -328,15 +328,6 @@ config BRANCH_TRACER
Say N if unsure.
-config POWER_TRACER
- bool "Trace power consumption behavior"
- depends on X86
- select GENERIC_TRACER
- help
- This tracer helps developers to analyze and optimize the kernel's
- power management decisions, specifically the C-state and P-state
- behavior.
-
config KSYM_TRACER
bool "Trace read and write access on kernel memory locations"
depends on HAVE_HW_BREAKPOINT
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b477fce41ed..fd05bcaf91b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -792,7 +792,8 @@ extern const char *__stop___trace_bprintk_fmt[];
#undef FTRACE_ENTRY
#define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \
- extern struct ftrace_event_call event_##call;
+ extern struct ftrace_event_call \
+ __attribute__((__aligned__(4))) event_##call;
#undef FTRACE_ENTRY_DUP
#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print) \
FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index c2a3077b735..3f972ad98d0 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -60,10 +60,8 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
return 0;
err:
- if (field) {
+ if (field)
kfree(field->name);
- kfree(field->type);
- }
kfree(field);
return -ENOMEM;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 616b135c9eb..112561df2a0 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -855,7 +855,6 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
int i;
if (data) {
- int cpu = iter->cpu;
int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
/*
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 53f748b64ef..465b36bef4c 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -651,12 +651,12 @@ static int create_trace_probe(int argc, char **argv)
event = strchr(group, '/') + 1;
event[-1] = '\0';
if (strlen(group) == 0) {
- pr_info("Group name is not specifiled\n");
+ pr_info("Group name is not specified\n");
return -EINVAL;
}
}
if (strlen(event) == 0) {
- pr_info("Event name is not specifiled\n");
+ pr_info("Event name is not specified\n");
return -EINVAL;
}
}
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 49cea70fbf6..8cdda95da81 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -603,7 +603,7 @@ int prof_sysexit_enable(struct ftrace_event_call *call)
ret = register_trace_sys_exit(prof_syscall_exit);
if (ret) {
pr_info("event trace: Could not activate"
- "syscall entry trace point");
+ "syscall exit trace point");
} else {
set_bit(num, enabled_prof_exit_syscalls);
sys_prof_refcount_exit++;