From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olivier Matz Subject: Re: [PATCH] mempool: introduce flag to indicate hw mempool Date: Mon, 3 Apr 2017 17:19:58 +0200 Message-ID: <20170403171958.5ff2f3ab@platinum> References: <1491210729-9755-1-git-send-email-hemant.agrawal@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: , To: Hemant Agrawal Return-path: Received: from mail-lf0-f52.google.com (mail-lf0-f52.google.com [209.85.215.52]) by dpdk.org (Postfix) with ESMTP id E0F342C2F for ; Mon, 3 Apr 2017 17:20:01 +0200 (CEST) Received: by mail-lf0-f52.google.com with SMTP id z15so76861821lfd.1 for ; Mon, 03 Apr 2017 08:20:01 -0700 (PDT) In-Reply-To: <1491210729-9755-1-git-send-email-hemant.agrawal@nxp.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Hemant, On Mon, 3 Apr 2017 14:42:09 +0530, Hemant Agrawal wrote: > Hardware pools need to distinguish between buffers allocated using > software or hardware backed pools. > > Some HW NICs may choose to autonomously free the pickets during > transmit if the packet is from HW pool. While they should not do > it for software backed pools. > > Such flag would also help when multiple pools are being handled by > a PMD, saving costly compare operations for any internal marker. > > Signed-off-by: Hemant Agrawal > --- > lib/librte_mempool/rte_mempool.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h > index 991feaa..91dbd21 100644 > --- a/lib/librte_mempool/rte_mempool.h > +++ b/lib/librte_mempool/rte_mempool.h > @@ -263,6 +263,11 @@ struct rte_mempool { > #define MEMPOOL_F_SC_GET 0x0008 /**< Default get is "single-consumer".*/ > #define MEMPOOL_F_POOL_CREATED 0x0010 /**< Internal: pool is created. */ > #define MEMPOOL_F_NO_PHYS_CONTIG 0x0020 /**< Don't need physically contiguous objs. */ > +#define MEMPOOL_F_HW_POOL (1 << ((sizeof(int) * 8) - 1)) /**< Internal: > + * Hardware offloaded pool. This information may be used by the > + * NIC or other hw. Some NICs autonomously free the HW backed pool packets. */ > + > +/**< Don't need physically contiguous objs. */ > > /** > * @internal When debug is enabled, store some statistics. One thing is still not clear to me: in your driver, you check this flag: - if it is unset, you reallocate a packet from your hw pool, you copy some metadata, and you send it to the hw. - if it is set, you assume that you can call mempool_to_bpid(mp) and directly send it to the hw. I think this is not correct. The test you want to do in your driver is: "is it the pool that I registered for my hardware"? It is not: "is it a hardware managed pool?". I think what you are doing here prevents to use 2 hardware mempools at the same time, because they would all have this flag, and mempool_to_bpid() would probably crash. Instead, can't you just compare the mempool pointer to a value stored internally in the driver? Olivier