log: call vsnprintf only when it is needed to emit trace
Reduce the log overhead when the traces are filtered,
by moving the vsnprintf call from _log() to log_dispatch().
This patch avoids the printf treatment when LOG features is
activated, but trace is filtered, for example when
MAX_LOG_LEVEL=8 and LOG_DEFAULT_LEVEL=6.
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/common/log.c b/common/log.c
index a4ed7d7..767f0fe 100644
--- a/common/log.c
+++ b/common/log.c
@@ -198,9 +198,10 @@
* @rec: log record to dispatch
* Return: 0 msg sent, 1 msg not sent while already dispatching another msg
*/
-static int log_dispatch(struct log_rec *rec)
+static int log_dispatch(struct log_rec *rec, const char *fmt, va_list args)
{
struct log_device *ldev;
+ char buf[CONFIG_SYS_CBSIZE];
/*
* When a log driver writes messages (e.g. via the network stack) this
@@ -214,8 +215,13 @@
gd->processing_msg = true;
list_for_each_entry(ldev, &gd->log_head, sibling_node) {
if ((ldev->flags & LOGDF_ENABLE) &&
- log_passes_filters(ldev, rec))
+ log_passes_filters(ldev, rec)) {
+ if (!rec->msg) {
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ rec->msg = buf;
+ }
ldev->drv->emit(ldev, rec);
+ }
}
gd->processing_msg = false;
return 0;
@@ -224,7 +230,6 @@
int _log(enum log_category_t cat, enum log_level_t level, const char *file,
int line, const char *func, const char *fmt, ...)
{
- char buf[CONFIG_SYS_CBSIZE];
struct log_rec rec;
va_list args;
@@ -243,12 +248,15 @@
rec.file = file;
rec.line = line;
rec.func = func;
+ rec.msg = NULL;
if (!(gd->flags & GD_FLG_LOG_READY)) {
gd->log_drop_count++;
/* display dropped traces with console puts and DEBUG_UART */
if (rec.level <= CONFIG_LOG_DEFAULT_LEVEL || rec.force_debug) {
+ char buf[CONFIG_SYS_CBSIZE];
+
va_start(args, fmt);
vsnprintf(buf, sizeof(buf), fmt, args);
puts(buf);
@@ -258,13 +266,11 @@
return -ENOSYS;
}
va_start(args, fmt);
- vsnprintf(buf, sizeof(buf), fmt, args);
- va_end(args);
- rec.msg = buf;
- if (!log_dispatch(&rec)) {
+ if (!log_dispatch(&rec, fmt, args)) {
gd->logc_prev = cat;
gd->logl_prev = level;
}
+ va_end(args);
return 0;
}