From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olivier Matz <olivier.matz@6wind.com>
Subject: Re: [PATCH v1 3/9] mempool: remove callback to get
 capabilities
Date: Mon, 19 Mar 2018 18:05:19 +0100
Message-ID: <20180319170519.hyxbdjbr3nral6ho@platinum>
References: <1520696382-16400-1-git-send-email-arybchenko@solarflare.com>
 <1520696382-16400-4-git-send-email-arybchenko@solarflare.com>
 <a3292ce8-59f0-575c-efbc-22efd06a3090@intel.com>
 <72792bc9-8e64-9a18-ce6c-ffd6777f1748@solarflare.com>
 <216ac4e5-2815-de23-4185-fd28210c0477@intel.com>
 <f3148dd6-10c3-7fbb-e73b-b8f43d0a4bd3@solarflare.com>
 <b26d07a8-5e99-85f1-1948-5b8d81979134@intel.com>
 <7873dc42-d58f-7dd2-abe0-3eac3ee5ebfb@solarflare.com>
 <7e266ed5-862f-8ecb-d80d-c26c7a7e4e4c@intel.com>
 <ce185632-08af-e8f7-8a34-d582ead20d8c@solarflare.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: "Burakov, Anatoly" <anatoly.burakov@intel.com>, dev@dpdk.org
To: Andrew Rybchenko <arybchenko@solarflare.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67])
 by dpdk.org (Postfix) with ESMTP id 290F81B04C
 for <dev@dpdk.org>; Mon, 19 Mar 2018 18:05:24 +0100 (CET)
Content-Disposition: inline
In-Reply-To: <ce185632-08af-e8f7-8a34-d582ead20d8c@solarflare.com>
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>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

Hi,

On Thu, Mar 15, 2018 at 03:44:34PM +0300, Andrew Rybchenko wrote:

[...]

> > > Aha, you're saying that virtual-contiguous and IOVA-contiguous
> > > requirements are different things that it could be usecases where
> > > virtual contiguous is important but IOVA-contiguos is not required.
> > > It is perfectly fine.
> > > As I understand IOVA-contiguous (physical) typically means
> > > virtual-contiguous as well. Requirements to have everything
> > > virtually contiguous and some blocks physically contiguous are
> > > unlikely. So, it may be reduced to either virtual or physical
> > > contiguous. If mempool does not care about physical contiguous at
> > > all, MEMPOOL_F_NO_PHYS_CONTIG flag should be used and min_chunk_size
> > > should mean virtual contiguous requirements. If mempool requires
> > > physical contiguous objects, there is *no* MEMPOOL_F_NO_PHYS_CONTIG
> > > flag and min_chunk_size means physical contiguous requirements.

Just as a side note, from what I understood, having VA="contiguous" and
IOVA="don't care" would be helpful for mbuf pools with mellanox drivers
because perform better in that case.