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tracing/user_events: Optimize safe list traversals

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Several of the list traversals in the user_events facility use safe list
traversals where they could be using the unsafe versions instead.

Replace these safe traversals with their unsafe counterparts in the
interest of optimization.

Link: https://lore.kernel.org/linux-trace-kernel/20230810194337.695983-1-ervaughn@linux.microsoft.com

Suggested-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Eric Vaughn 2023-08-10 12:43:37 -07:00 committed by Steven Rostedt (Google)
parent c8f05f2f41
commit a943188dab
1 changed files with 8 additions and 7 deletions
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15
kernel/trace/trace_events_user.c
View file

@ -1328,14 +1328,14 @@ static int user_field_set_string(struct ftrace_event_field *field,
static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
{
struct ftrace_event_field *field, *next;
struct ftrace_event_field *field;
struct list_head *head = &user->fields;
int pos = 0, depth = 0;
const char *str_func;
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
list_for_each_entry_safe_reverse(field, next, head, link) {
list_for_each_entry_reverse(field, head, link) {
if (depth != 0)
pos += snprintf(buf + pos, LEN_OR_ZERO, " ");
@ -1347,7 +1347,7 @@ static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
list_for_each_entry_safe_reverse(field, next, head, link) {
list_for_each_entry_reverse(field, head, link) {
if (user_field_is_dyn_string(field->type, &str_func))
pos += snprintf(buf + pos, LEN_OR_ZERO,
", %s(%s)", str_func, field->name);
@ -1732,7 +1732,7 @@ static int user_event_create(const char *raw_command)
static int user_event_show(struct seq_file *m, struct dyn_event *ev)
{
struct user_event *user = container_of(ev, struct user_event, devent);
struct ftrace_event_field *field, *next;
struct ftrace_event_field *field;
struct list_head *head;
int depth = 0;
@ -1740,7 +1740,7 @@ static int user_event_show(struct seq_file *m, struct dyn_event *ev)
head = trace_get_fields(&user->call);
list_for_each_entry_safe_reverse(field, next, head, link) {
list_for_each_entry_reverse(field, head, link) {
if (depth == 0)
seq_puts(m, " ");
else
@ -1816,13 +1816,14 @@ static bool user_field_match(struct ftrace_event_field *field, int argc,
static bool user_fields_match(struct user_event *user, int argc,
const char **argv)
{
struct ftrace_event_field *field, *next;
struct ftrace_event_field *field;
struct list_head *head = &user->fields;
int i = 0;
list_for_each_entry_safe_reverse(field, next, head, link)
list_for_each_entry_reverse(field, head, link) {
if (!user_field_match(field, argc, argv, &i))
return false;
}
if (i != argc)
return false;