Skip to content

Commit

Permalink
tracing: Don't allocate common fields for every trace events
Browse files Browse the repository at this point in the history 
Every event has the same common fields, so it's a big waste of
memory to have a copy of those fields for every event.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA3759.30105@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
  • Loading branch information
Li Zefan authored and Steven Rostedt committed Jun 28, 2010
1 parent c9642c4 commit 8728fe5
Show file tree
Hide file tree
Showing 3 changed files with 81 additions and 52 deletions.
2 changes: 2 additions & 0 deletions kernel/trace/trace.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -698,6 +698,8 @@ struct filter_pred {
int pop_n;
};

extern struct list_head ftrace_common_fields;

extern enum regex_type
filter_parse_regex(char *buff, int len, char **search, int *not);
extern void print_event_filter(struct ftrace_event_call *call,
Expand Down
113 changes: 64 additions & 49 deletions kernel/trace/trace_events.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,7 @@
DEFINE_MUTEX(event_mutex);

LIST_HEAD(ftrace_events);
LIST_HEAD(ftrace_common_fields);

struct list_head *
trace_get_fields(struct ftrace_event_call *event_call)
Expand All @@ -37,15 +38,11 @@ trace_get_fields(struct ftrace_event_call *event_call)
return event_call->class->get_fields(event_call);
}

int trace_define_field(struct ftrace_event_call *call, const char *type,
const char *name, int offset, int size, int is_signed,
int filter_type)
static int __trace_define_field(struct list_head *head, const char *type,
const char *name, int offset, int size,
int is_signed, int filter_type)
{
struct ftrace_event_field *field;
struct list_head *head;

if (WARN_ON(!call->class))
return 0;

field = kzalloc(sizeof(*field), GFP_KERNEL);
if (!field)
Expand All @@ -68,7 +65,6 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
field->size = size;
field->is_signed = is_signed;

head = trace_get_fields(call);
list_add(&field->link, head);

return 0;
Expand All @@ -80,17 +76,32 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,

return -ENOMEM;
}

int trace_define_field(struct ftrace_event_call *call, const char *type,
const char *name, int offset, int size, int is_signed,
int filter_type)
{
struct list_head *head;

if (WARN_ON(!call->class))
return 0;

head = trace_get_fields(call);
return __trace_define_field(head, type, name, offset, size,
is_signed, filter_type);
}
EXPORT_SYMBOL_GPL(trace_define_field);

#define __common_field(type, item) \
ret = trace_define_field(call, #type, "common_" #item, \
offsetof(typeof(ent), item), \
sizeof(ent.item), \
is_signed_type(type), FILTER_OTHER); \
ret = __trace_define_field(&ftrace_common_fields, #type, \
"common_" #item, \
offsetof(typeof(ent), item), \
sizeof(ent.item), \
is_signed_type(type), FILTER_OTHER); \
if (ret) \
return ret;

static int trace_define_common_fields(struct ftrace_event_call *call)
static int trace_define_common_fields(void)
{
int ret;
struct trace_entry ent;
Expand Down Expand Up @@ -544,32 +555,10 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
return ret;
}

static ssize_t
event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
static void print_event_fields(struct trace_seq *s, struct list_head *head)
{
struct ftrace_event_call *call = filp->private_data;
struct ftrace_event_field *field;
struct list_head *head;
struct trace_seq *s;
int common_field_count = 5;
char *buf;
int r = 0;

if (*ppos)
return 0;

s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;

trace_seq_init(s);

trace_seq_printf(s, "name: %s\n", call->name);
trace_seq_printf(s, "ID: %d\n", call->event.type);
trace_seq_printf(s, "format:\n");

head = trace_get_fields(call);
list_for_each_entry_reverse(field, head, link) {
/*
* Smartly shows the array type(except dynamic array).
Expand All @@ -584,29 +573,54 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
array_descriptor = NULL;

if (!array_descriptor) {
r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
"\tsize:%u;\tsigned:%d;\n",
field->type, field->name, field->offset,
field->size, !!field->is_signed);
} else {
r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
"\tsize:%u;\tsigned:%d;\n",
(int)(array_descriptor - field->type),
field->type, field->name,
array_descriptor, field->offset,
field->size, !!field->is_signed);
}
}
}

if (--common_field_count == 0)
r = trace_seq_printf(s, "\n");
static ssize_t
event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
struct ftrace_event_call *call = filp->private_data;
struct list_head *head;
struct trace_seq *s;
char *buf;
int r;

if (!r)
break;
}
if (*ppos)
return 0;

if (r)
r = trace_seq_printf(s, "\nprint fmt: %s\n",
call->print_fmt);
s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;

trace_seq_init(s);

trace_seq_printf(s, "name: %s\n", call->name);
trace_seq_printf(s, "ID: %d\n", call->event.type);
trace_seq_printf(s, "format:\n");

/* print common fields */
print_event_fields(s, &ftrace_common_fields);

trace_seq_putc(s, '\n');

/* print event specific fields */
head = trace_get_fields(call);
print_event_fields(s, head);

r = trace_seq_printf(s, "\nprint fmt: %s\n", call->print_fmt);

if (!r) {
/*
Expand Down Expand Up @@ -980,9 +994,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
*/
head = trace_get_fields(call);
if (list_empty(head)) {
ret = trace_define_common_fields(call);
if (!ret)
ret = call->class->define_fields(call);
ret = call->class->define_fields(call);
if (ret < 0) {
pr_warning("Could not initialize trace point"
" events/%s\n", call->name);
Expand Down Expand Up @@ -1319,6 +1331,9 @@ static __init int event_trace_init(void)
trace_create_file("enable", 0644, d_events,
NULL, &ftrace_system_enable_fops);

if (trace_define_common_fields())
pr_warning("tracing: Failed to allocate common fields");

for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
/* The linker may leave blanks */
if (!call->name)
Expand Down
18 changes: 15 additions & 3 deletions kernel/trace/trace_events_filter.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -497,12 +497,10 @@ void print_subsystem_event_filter(struct event_subsystem *system,
}

static struct ftrace_event_field *
find_event_field(struct ftrace_event_call *call, char *name)
__find_event_field(struct list_head *head, char *name)
{
struct ftrace_event_field *field;
struct list_head *head;

head = trace_get_fields(call);
list_for_each_entry(field, head, link) {
if (!strcmp(field->name, name))
return field;
Expand All @@ -511,6 +509,20 @@ find_event_field(struct ftrace_event_call *call, char *name)
return NULL;
}

static struct ftrace_event_field *
find_event_field(struct ftrace_event_call *call, char *name)
{
struct ftrace_event_field *field;
struct list_head *head;

field = __find_event_field(&ftrace_common_fields, name);
if (field)
return field;

head = trace_get_fields(call);
return __find_event_field(head, name);
}

static void filter_free_pred(struct filter_pred *pred)
{
if (!pred)
Expand Down

0 comments on commit 8728fe5

Please sign in to comment.