[sheepdog] [PATCH] add likely/unlikely to performance critical path

MORITA Kazutaka morita.kazutaka at gmail.com
Sat Aug 10 01:31:29 CEST 2013


At Sat, 10 Aug 2013 02:05:40 +0800,
Liu Yuan wrote:
> 
> diff --git a/lib/util.c b/lib/util.c
> index 2f877c4..82356d6 100644
> --- a/lib/util.c
> +++ b/lib/util.c
> @@ -46,9 +46,9 @@ try_to_free_t set_try_to_free_routine(try_to_free_t routine)
>  void *xmalloc(size_t size)
>  {
>  	void *ret = malloc(size);
> -	if (!ret && !size)
> +	if (unlikely(!ret) && unlikely(!size))
>  		ret = malloc(1);
> -	if (!ret) {
> +	if (unlikely(!ret)) {
>  		try_to_free_routine(size);
>  		ret = malloc(size);
>  		if (!ret && !size)
> @@ -67,9 +67,9 @@ void *xzalloc(size_t size)
>  void *xrealloc(void *ptr, size_t size)
>  {
>  	void *ret = realloc(ptr, size);
> -	if (!ret && !size)
> +	if (unlikely(!ret) && unlikely(!size))
>  		ret = realloc(ptr, 1);
> -	if (!ret) {
> +	if (unlikely(!ret)) {
>  		try_to_free_routine(size);
>  		ret = realloc(ptr, size);
>  		if (!ret && !size)
> @@ -83,9 +83,9 @@ void *xrealloc(void *ptr, size_t size)
>  void *xcalloc(size_t nmemb, size_t size)
>  {
>  	void *ret = calloc(nmemb, size);
> -	if (!ret && (!nmemb || !size))
> +	if (unlikely(!ret) && (!nmemb || !size))

Should be unlikey(!nmemb || !size) like xmalloc and xrealloc?

Thanks

Kazutaka


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