From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [PATCH] eal: optimize timer routines
Date: Mon, 01 May 2017 21:52:44 +0200
Message-ID: <1783111.z13ClxBXEf@xps>
References: <20170501191207.6480-1-jerin.jacob@caviumnetworks.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7Bit
Cc: dev@dpdk.org
To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Return-path: <dev-bounces@dpdk.org>
Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com
 [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 6937C5A98
 for <dev@dpdk.org>; Mon,  1 May 2017 21:52:46 +0200 (CEST)
In-Reply-To: <20170501191207.6480-1-jerin.jacob@caviumnetworks.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

01/05/2017 21:12, Jerin Jacob:
> Since DPDK has only two timer sources,
> Avoid &eal_timer_source memory read and followed
> by the switch case statement when
> RTE_LIBEAL_USE_HPET is not defined.
[...]
>  static inline uint64_t
>  rte_get_timer_cycles(void)
>  {
> +#ifdef RTE_LIBEAL_USE_HPET
>  	switch(eal_timer_source) {
>  	case EAL_TIMER_TSC:
>  		return rte_get_tsc_cycles();
>  	case EAL_TIMER_HPET:
> -#ifdef RTE_LIBEAL_USE_HPET
>  		return rte_get_hpet_cycles();
> -#endif
>  	default: rte_panic("Invalid timer source specified\n");
>  	}
> +#else
> +	return rte_get_tsc_cycles();
> +#endif

I think I would prefer avoiding the #else part by
"unifdef" the first occurence of rte_get_tsc_cycles:

static inline uint64_t
rte_get_timer_cycles(void)
{
#ifdef RTE_LIBEAL_USE_HPET
	switch(eal_timer_source) {
	case EAL_TIMER_TSC:
#endif
		return rte_get_tsc_cycles();
#ifdef RTE_LIBEAL_USE_HPET
	case EAL_TIMER_HPET:
		return rte_get_hpet_cycles();
	default: rte_panic("Invalid timer source specified\n");
	}
#endif