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tracing/filters: Defer pred allocation 

init_preds() allocates about 5392 bytes of memory (on x86_32) for
a TRACE_EVENT. With my config, at system boot total memory occupied
is:

	5392 * (642 + 15) == 3459KB

642 == cat available_events | wc -l
15 == number of dirs in events/ftrace

That's quite a lot, so we'd better defer memory allocation util
it's needed, that's when filter is used.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4A9B8EA5.6020700@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-08-31 16:49:41 +08:00 committed by Ingo Molnar
parent 73222acf96
commit 8e254c1d18
5 changed files with 41 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/ftrace_event.h
View File

@ -133,7 +133,6 @@ struct ftrace_event_call {
#define MAX_FILTER_PRED 32
#define MAX_FILTER_STR_VAL 128
extern int init_preds(struct ftrace_event_call *call);
extern void destroy_preds(struct ftrace_event_call *call);
extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
extern int filter_current_check_discard(struct ftrace_event_call *call,

2
include/linux/syscalls.h
View File

@ -177,7 +177,6 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
event_enter_##sname.id = id; \
set_syscall_enter_id(num, id); \
INIT_LIST_HEAD(&event_enter_##sname.fields); \
init_preds(&event_enter_##sname); \
return 0; \
} \
TRACE_SYS_ENTER_PROFILE(sname); \
@ -214,7 +213,6 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
event_exit_##sname.id = id; \
set_syscall_exit_id(num, id); \
INIT_LIST_HEAD(&event_exit_##sname.fields); \
init_preds(&event_exit_##sname); \
return 0; \
} \
TRACE_SYS_EXIT_PROFILE(sname); \

1
include/trace/ftrace.h
View File

@ -622,7 +622,6 @@ static int ftrace_raw_init_event_##call(void) \
return -ENODEV; \
event_##call.id = id; \
INIT_LIST_HEAD(&event_##call.fields); \
init_preds(&event_##call); \
return 0; \
} \
\

50
kernel/trace/trace_events_filter.c
View File

@ -309,7 +309,7 @@ void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
struct event_filter *filter = call->filter;
mutex_lock(&event_mutex);
if (filter->filter_string)
if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
@ -322,7 +322,7 @@ void print_subsystem_event_filter(struct event_subsystem *system,
struct event_filter *filter = system->filter;
mutex_lock(&event_mutex);
if (filter->filter_string)
if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
@ -390,6 +390,9 @@ void destroy_preds(struct ftrace_event_call *call)
struct event_filter *filter = call->filter;
int i;
if (!filter)
return;
for (i = 0; i < MAX_FILTER_PRED; i++) {
if (filter->preds[i])
filter_free_pred(filter->preds[i]);
@ -400,7 +403,7 @@ void destroy_preds(struct ftrace_event_call *call)
call->filter = NULL;
}
int init_preds(struct ftrace_event_call *call)
static int init_preds(struct ftrace_event_call *call)
{
struct event_filter *filter;
struct filter_pred *pred;
@ -410,7 +413,6 @@ int init_preds(struct ftrace_event_call *call)
if (!call->filter)
return -ENOMEM;
call->filter_active = 0;
filter->n_preds = 0;
filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
@ -432,7 +434,28 @@ oom:
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(init_preds);
static int init_subsystem_preds(struct event_subsystem *system)
{
struct ftrace_event_call *call;
int err;
list_for_each_entry(call, &ftrace_events, list) {
if (!call->define_fields)
continue;
if (strcmp(call->system, system->name) != 0)
continue;
if (!call->filter) {
err = init_preds(call);
if (err)
return err;
}
}
return 0;
}
enum {
FILTER_DISABLE_ALL,
@ -449,6 +472,9 @@ static void filter_free_subsystem_preds(struct event_subsystem *system,
if (!call->define_fields)
continue;
if (strcmp(call->system, system->name) != 0)
continue;
if (flag == FILTER_INIT_NO_RESET) {
call->filter->no_reset = false;
continue;
@ -457,10 +483,8 @@ static void filter_free_subsystem_preds(struct event_subsystem *system,
if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset)
continue;
if (!strcmp(call->system, system->name)) {
filter_disable_preds(call);
remove_filter_string(call->filter);
}
filter_disable_preds(call);
remove_filter_string(call->filter);
}
}
@ -1094,6 +1118,10 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
mutex_lock(&event_mutex);
err = init_preds(call);
if (err)
goto out_unlock;
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable_preds(call);
remove_filter_string(call->filter);
@ -1139,6 +1167,10 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
mutex_lock(&event_mutex);
err = init_subsystem_preds(system);
if (err)
goto out_unlock;
if (!strcmp(strstrip(filter_string), "0")) {
filter_free_subsystem_preds(system, FILTER_DISABLE_ALL);
remove_filter_string(system->filter);

1
kernel/trace/trace_export.c
View File

@ -135,7 +135,6 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
static int ftrace_raw_init_event_##call(void) \
{ \
INIT_LIST_HEAD(&event_##call.fields); \
init_preds(&event_##call); \
return 0; \
} \