When debugfs is not enabled, the deferred_probe_reason string is never read. So there's no reason to spend time and memory on recording it.
There's still a bunch of redundant kfree(NULL) calls and NULL assignments, but this gives most of the benefit (avoiding two vsnprintf() and a kmalloc()) for the minimal amount of ifdeffery. Signed-off-by: Rasmus Villemoes <li...@rasmusvillemoes.dk> --- drivers/base/dd.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 37a5e5f8b221..6a197336c6a4 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -216,9 +216,13 @@ void device_unblock_probing(void) * device_set_deferred_probe_reason() - Set defer probe reason message for device * @dev: the pointer to the struct device * @vaf: the pointer to va_format structure with message + * + * The ->deferred_probe_reason string is only ever read when debugfs + * is enabled, so this is a no-op for !CONFIG_DEBUG_FS. */ void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf) { +#ifdef CONFIG_DEBUG_FS const char *drv = dev_driver_string(dev); mutex_lock(&deferred_probe_mutex); @@ -227,6 +231,7 @@ void device_set_deferred_probe_reason(const struct device *dev, struct va_format dev->p->deferred_probe_reason = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf); mutex_unlock(&deferred_probe_mutex); +#endif } /* -- 2.29.2