From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Harton (dharton)" Subject: Re: [PATCH v2 1/2] ethdev: stop overriding rx_nombuf by rte_eth_stats_get Date: Wed, 23 Aug 2017 21:27:35 +0000 Message-ID: <840715e081a542788c217ef639dac766@XCH-RCD-016.cisco.com> References: <20170823011937.37579-1-dharton@cisco.com> <1679481.0OI12NtS3X@xps> <3459676.trPQTB1ucG@xps> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "dev@dpdk.org" To: Thomas Monjalon Return-path: Received: from rcdn-iport-3.cisco.com (rcdn-iport-3.cisco.com [173.37.86.74]) by dpdk.org (Postfix) with ESMTP id 0C5E27D53 for ; Wed, 23 Aug 2017 23:27:37 +0200 (CEST) In-Reply-To: <3459676.trPQTB1ucG@xps> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" > -----Original Message----- > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Wednesday, August 23, 2017 9:24 AM > To: David Harton (dharton) > Cc: dev@dpdk.org > Subject: Re: [PATCH v2 1/2] ethdev: stop overriding rx_nombuf by > rte_eth_stats_get >=20 > 23/08/2017 14:18, David Harton (dharton): > > > > > -----Original Message----- > > > From: Thomas Monjalon [mailto:thomas@monjalon.net] > > > Sent: Wednesday, August 23, 2017 3:52 AM > > > To: David Harton (dharton) > > > Cc: dev@dpdk.org > > > Subject: Re: [PATCH v2 1/2] ethdev: stop overriding rx_nombuf by > > > rte_eth_stats_get > > > > > > 23/08/2017 04:55, David Harton: > > > > rte_eth_stats_get() unconditonally would set rx_nombuf even if the > > > > device was setting the value. A check has been added in > > > > rte_eth_stats_get() to leave the device value in-tact when non-zero= . > > > > > > If we get this counter from stats->rx_nombuf, why keeping > > > dev->data->rx_mbuf_alloc_failed ? > > > We could rework other PMDs to not use this global variable. > > > It is inconsistent to use it for some PMDs but not all. > > > And it seems not used outside of PMDs. > > > > Are you also asking to remove dev->data->rx_mbuf_alloc_failed as well > since we will have an ABI breakage anyway? >=20 > Not asking, just giving my thought :) I did some more digging. For this count it looks like some devices: - have their own internal version - have a count shared with the pf - rely on this field to maintain the count - don't count this failure at all :( With that said I'd like to keep with the requested changes. Thoughts? Dave >=20 > > On an somewhat related note, since we are introducing an ABI breakage > how do you feel about re-adding the return code for the vlan_offload_set > vector? Some devices conditionally provide the ability to modify some > offload and the caller should know. Since I've got your attention though= t > I'd ask here before posting the patch. >=20 > Seems reasonnable >=20 > > > > In fact, I believe all the API function calls should provide a return > code to help mitigate ABI breakages and also provide the ability to let > the caller distinguish between - no device, not supported and some other > error. A control plane often needs to understand these distinctions to > properly orchestrate the system and/or report real errors. This is more > than I'm willing to take on myself but believe it's a principle I'd like > to discuss (can start separate thread if desired). > > >=20 > Yes you're right