From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH] doc: announce xstats api change for 16.07 Date: Wed, 06 Apr 2016 14:14:23 +0200 Message-ID: <23174662.vdJtoqjRUU@xps13> References: <1459879089-3430-1-git-send-email-harry.van.haaren@intel.com> <27546869.TpcjJvEkXE@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: "'David Harton (dharton)'" , dev@dpdk.org, "Tahhan, Maryam" , "olivier.matz@6wind.com" To: "Van Haaren, Harry" Return-path: Received: from mail-wm0-f41.google.com (mail-wm0-f41.google.com [74.125.82.41]) by dpdk.org (Postfix) with ESMTP id A374B293B for ; Wed, 6 Apr 2016 14:16:02 +0200 (CEST) Received: by mail-wm0-f41.google.com with SMTP id u206so42796535wme.1 for ; Wed, 06 Apr 2016 05:16:02 -0700 (PDT) In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 2016-04-06 11:16, Van Haaren, Harry: > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > > > The issue we are going to fix is that currently PMDs copy strings when retrieving > > statistics, which causes unnecessary overhead. The implementation is not decided yet, but > > using an int->value mapping seems logical. > > > I am not sure performance is so much critical when retrieving statistics. > > In the previous discussion David was concerned about performance impact > of string copies, are those concerns still present David? > > > The extended stats can be infinitely extended. So a string identifier seems > > a lot more natural. > > I'm not suggesting that the string identifier is removed totally. > > > I do not agree to add a new numeric identifier in the API each time a driver > > wants to report a specific statistic for debugging purpose. > > And I agree - the ints are just an index to xstats arrays, no eth-dev wide enums here. > The proposal is to make the API more flexible, see example: > http://thread.gmane.org/gmane.comp.networking.dpdk.devel/31728/focus=32795 > > This more flexible API would allow other types of information about > statistics be retrieved too. OK I think I start to understand. > For now, the sent patch announces that the API/ABI may change, and we can > discuss details of API as development starts. This should not be the normal process. It is important to understand what should be the changes to decide of announcing or not a deprecation. In the case of the mempool reworks, the patch have been sent and discussed on the mailing list. Given the previous explanations (and knowing you did good job on stats), I give my Acked-by: Thomas Monjalon