From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <olivier.matz@6wind.com>
Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67])
 by dpdk.org (Postfix) with ESMTP id 958921D8E
 for <dev@dpdk.org>; Thu, 14 Dec 2017 14:38:45 +0100 (CET)
Received: from lfbn-lil-1-110-231.w90-45.abo.wanadoo.fr ([90.45.197.231]
 helo=droids-corp.org)
 by mail.droids-corp.org with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:256)
 (Exim 4.84_2) (envelope-from <olivier.matz@6wind.com>)
 id 1ePTou-0007ZH-0D; Thu, 14 Dec 2017 14:45:05 +0100
Received: by droids-corp.org (sSMTP sendmail emulation);
 Thu, 14 Dec 2017 14:38:38 +0100
Date: Thu, 14 Dec 2017 14:38:38 +0100
From: Olivier MATZ <olivier.matz@6wind.com>
To: Andrew Rybchenko <arybchenko@solarflare.com>
Cc: dev@dpdk.org, "Artem V. Andreev" <Artem.Andreev@oktetlabs.ru>
Message-ID: <20171214133837.y5feayfpoxeou6z3@platinum>
References: <1511539591-20966-1-git-send-email-arybchenko@solarflare.com>
 <1511539591-20966-5-git-send-email-arybchenko@solarflare.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1511539591-20966-5-git-send-email-arybchenko@solarflare.com>
User-Agent: NeoMutt/20170113 (1.7.2)
Subject: Re: [dpdk-dev] [RFC PATCH 4/6] mempool: add a function to flush
	default cache
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://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: <https://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Thu, 14 Dec 2017 13:38:45 -0000

On Fri, Nov 24, 2017 at 04:06:29PM +0000, Andrew Rybchenko wrote:
> From: "Artem V. Andreev" <Artem.Andreev@oktetlabs.ru>
> 
> Mempool get/put API cares about cache itself, but sometimes it is
> required to flush the cache explicitly.

I don't disagree, but do you have some use-case in mind?


> Also dedicated API allows to decouple it from block get API (to be
> added) and provides more fine-grained control.
> 
> Signed-off-by: Artem V. Andreev <Artem.Andreev@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
> ---
>  lib/librte_mempool/rte_mempool.h | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
> index 9bcb8b7..3a52b93 100644
> --- a/lib/librte_mempool/rte_mempool.h
> +++ b/lib/librte_mempool/rte_mempool.h
> @@ -1161,6 +1161,22 @@ rte_mempool_default_cache(struct rte_mempool *mp, unsigned lcore_id)
>  }
>  
>  /**
> + * Ensure that a default per-lcore mempool cache is flushed, if it is present
> + *
> + * @param mp
> + *   A pointer to the mempool structure.
> + */
> +static __rte_always_inline void
> +rte_mempool_ensure_cache_flushed(struct rte_mempool *mp)
> +{
> +	struct rte_mempool_cache *cache;
> +	cache = rte_mempool_default_cache(mp, rte_lcore_id());
> +	if (cache != NULL && cache->len > 0)
> +		rte_mempool_cache_flush(cache, mp);
> +}
> +

We already have rte_mempool_cache_flush().
Why not just extending it instead of adding a new function?

I mean:

    static __rte_always_inline void
    rte_mempool_cache_flush(struct rte_mempool_cache *cache,
    			struct rte_mempool *mp)
    {
   +	if (cache == NULL)
   +		cache = rte_mempool_default_cache(mp, rte_lcore_id());
   +	if (cache == NULL || cache->len == 0)
   +		return;
    	rte_mempool_ops_enqueue_bulk(mp, cache->objs, cache->len);
    	cache->len = 0;
    }