From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 76410A04DD; Tue, 21 Jan 2020 15:02:00 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 0988A322C; Tue, 21 Jan 2020 15:02:00 +0100 (CET) Received: from proxy.6wind.com (host.76.145.23.62.rev.coltfrance.com [62.23.145.76]) by dpdk.org (Postfix) with ESMTP id 08F1E2C6D for ; Tue, 21 Jan 2020 15:01:58 +0100 (CET) Received: from glumotte.dev.6wind.com (unknown [10.16.0.195]) by proxy.6wind.com (Postfix) with ESMTP id D3FC1370810; Tue, 21 Jan 2020 15:01:57 +0100 (CET) Date: Tue, 21 Jan 2020 15:01:57 +0100 From: Olivier Matz To: Slava Ovsiienko Cc: Stephen Hemminger , "dev@dpdk.org" , Matan Azrad , Raslan Darawsheh , Ori Kam , Shahaf Shuler , "thomas@mellanox.net" Message-ID: <20200121140157.GP14387@glumotte.dev.6wind.com> References: <20191118094938.192850-1-shahafs@mellanox.com> <1579541003-2399-1-git-send-email-viacheslavo@mellanox.com> <1579541003-2399-2-git-send-email-viacheslavo@mellanox.com> <20200120124342.6b308e18@hermes.lan> <20200121081417.GO14387@glumotte.dev.6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [dpdk-dev] [PATCH v5 1/5] mbuf: introduce routine to get private mbuf pool flags X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Jan 21, 2020 at 09:13:48AM +0000, Slava Ovsiienko wrote: > > -----Original Message----- > > From: dev On Behalf Of Slava Ovsiienko > > Sent: Tuesday, January 21, 2020 10:24 > > To: Olivier Matz > > Cc: Stephen Hemminger ; dev@dpdk.org; > > Matan Azrad ; Raslan Darawsheh > > ; Ori Kam ; Shahaf Shuler > > ; thomas@mellanox.net > > Subject: Re: [dpdk-dev] [PATCH v5 1/5] mbuf: introduce routine to get private > > mbuf pool flags > > > > > -----Original Message----- > > > From: Olivier Matz > > > Sent: Tuesday, January 21, 2020 10:14 > > > To: Slava Ovsiienko > > > Cc: Stephen Hemminger ; dev@dpdk.org; > > > Matan Azrad ; Raslan Darawsheh > > > ; Ori Kam ; Shahaf Shuler > > > ; thomas@mellanox.net > > > Subject: Re: [PATCH v5 1/5] mbuf: introduce routine to get private > > > mbuf pool flags > > > > > > On Tue, Jan 21, 2020 at 08:00:17AM +0000, Slava Ovsiienko wrote: > > > > > -----Original Message----- > > > > > From: Stephen Hemminger > > > > > Sent: Monday, January 20, 2020 22:44 > > > > > To: Slava Ovsiienko > > > > > Cc: dev@dpdk.org; Matan Azrad ; Raslan > > > Darawsheh > > > > > ; Ori Kam ; Shahaf > > > > > Shuler ; olivier.matz@6wind.com; > > > thomas@mellanox.net > > > > > Subject: Re: [PATCH v5 1/5] mbuf: introduce routine to get private > > > > > mbuf pool flags > > > > > > > > > > On Mon, 20 Jan 2020 17:23:19 +0000 Viacheslav Ovsiienko > > > > > wrote: > > > > > > > > > > > The routine rte_pktmbuf_priv_flags is introduced to fetch the > > > > > > flags from the mbuf memory pool private structure in unified fashion. > > > > > > > > > > > > Signed-off-by: Viacheslav Ovsiienko > > > > > > Acked-by: Olivier Matz > > > > > > --- > > > > > > lib/librte_mbuf/rte_mbuf.h | 17 +++++++++++++++++ > > > > > > 1 file changed, 17 insertions(+) > > > > > > > > > > > > diff --git a/lib/librte_mbuf/rte_mbuf.h > > > > > > b/lib/librte_mbuf/rte_mbuf.h index 2d4bda2..9b0691d 100644 > > > > > > --- a/lib/librte_mbuf/rte_mbuf.h > > > > > > +++ b/lib/librte_mbuf/rte_mbuf.h > > > > > > @@ -306,6 +306,23 @@ struct rte_pktmbuf_pool_private { > > > > > > uint32_t flags; /**< reserved for future use. */ }; > > > > > > > > > > > > +/** > > > > > > + * Return the flags from private data in an mempool structure. > > > > > > + * > > > > > > + * @param mp > > > > > > + * A pointer to the mempool structure. > > > > > > + * @return > > > > > > + * The flags from the private data structure. > > > > > > + */ > > > > > > +static inline uint32_t > > > > > > +rte_pktmbuf_priv_flags(struct rte_mempool *mp) { > > > > > > + struct rte_pktmbuf_pool_private *mbp_priv; > > > > > > + > > > > > > + mbp_priv = (struct rte_pktmbuf_pool_private > > > > > *)rte_mempool_get_priv(mp); > > > > > > + return mbp_priv->flags; > > > > > > +} > > > > > > + > > > > > > #ifdef RTE_LIBRTE_MBUF_DEBUG > > > > > > > > > > > > /** check mbuf type in debug mode */ > > > > > > > > > > Looks fine, but a couple of minor suggestions. > > > > > > > > > > > > > > > Since this doesn't modify the mbuf, the arguments should be const. > > > > > Since rte_mempool_get_priv returns void *, the cast is unnecessary. > > > > > > > > rte_mempool_get_priv() does not expect "const", so adding "const" is > > > > a bit problematic, and we should not change the > > > > rte_mempool_get_priv() > > > prototype. > > > > Do you think we should take private structure pointer directly from > > > > the pool structure instead of calling rte_mempool_get_priv() ? > > > > > > I'm not sure it would work. The problem is that to get the priv, we do > > > pool_ptr + offset. So if we want to remove the const, we'll have to do > > > a cast to "unconst". Not sure it is worth doing it. > > > > > > Thanks > > > Olivier > > OK, I'll just remove not necessary (struct rte_pktmbuf_pool_private*) cast and > > will not introduce const qualifier for the parameter. > > > > With best regards, Slava > I've checked the rte_mempool_get_priv() usage - in all header files there > are the type casts. The "rte_mbuf.h" contains the rte_pktmbuf_priv_size() and > rte_pktmbuf_data_room_size(), both provide the cast. What is the reason? > C++ compatibility? Should we remove the cast in rte_pktmbuf_priv_flags()? Removing the cast will certainly break C++ code using this header. There is a similar case in commit a2ff2827dc84 ("mbuf: fix C++ build on void pointer cast") In my opinion it can stay as it is now.