| Message ID | 20230810194337.695983-1-ervaughn@linux.microsoft.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | a943188dabf78585fc5ddae0803b8b2c94f1c824 |
| Headers | show |
| Series | tracing/user_events: Optimize safe list traversals | expand |
On Thu, Aug 10, 2023 at 12:43:37PM -0700, Eric Vaughn wrote: > 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. > > Suggested-by: Beau Belgrave <beaub@linux.microsoft.com> > Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com> > --- Thanks for doing this, it looks good to me. Acked-by: Beau Belgrave <beaub@linux.microsoft.com> Thanks, -Beau > kernel/trace/trace_events_user.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c > index 33cb6af31f39..6f046650e527 100644 > --- a/kernel/trace/trace_events_user.c > +++ b/kernel/trace/trace_events_user.c > @@ -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; > -- > 2.34.1
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 33cb6af31f39..6f046650e527 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -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;
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. Suggested-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com> --- kernel/trace/trace_events_user.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)