From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roopa Prabhu Subject: Re: [PATCH iproute2 net-next] ifstat: move to new RTM_GETSTATS api Date: Tue, 10 May 2016 09:25:14 -0700 Message-ID: <57320B6A.3090301@cumulusnetworks.com> References: <1461998511-24193-1-git-send-email-roopa@cumulusnetworks.com> <57248720.8060001@mojatatu.com> <5724CC01.3030203@cumulusnetworks.com> <573016F1.8050700@cumulusnetworks.com> <573084AC.6030407@mojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: stephen@networkplumber.org, netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, tgraf@suug.ch, nicolas.dichtel@6wind.com, nikolay@cumulusnetworks.com To: Jamal Hadi Salim Return-path: Received: from mail-qk0-f175.google.com ([209.85.220.175]:35460 "EHLO mail-qk0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751890AbcEJQZS (ORCPT ); Tue, 10 May 2016 12:25:18 -0400 Received: by mail-qk0-f175.google.com with SMTP id n62so8740656qkc.2 for ; Tue, 10 May 2016 09:25:17 -0700 (PDT) In-Reply-To: <573084AC.6030407@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 5/9/16, 5:38 AM, Jamal Hadi Salim wrote: > On 16-05-09 12:49 AM, Roopa Prabhu wrote: >> On 4/30/16, 8:15 AM, Roopa Prabhu wrote: >>> On 4/30/16, 3:21 AM, Jamal Hadi Salim wrote: > >> AFAICS ifstat history file handling today assumes all 32 bit stats. > > Indeed it does. > >> And to preserve backward compatibility, new ifstat should work with old and >> new history files with 32bit and 64 bit stats. > > True. > It may be ok to just provide a conversion tool maybe for taking 32b > history into 64b? I dont know if someone is going to "migrate" their > history files so even that may not be worth it. > >> The file format cannot be changed because of the same backward compat issues. >> So, I am leaning towards a new history file with a new option (maybe ifstat -64) to >> save/query 64 bit stats using the new api when available. >> >> I see some previous brief discussions on moving ifstat to 64 bit. >> >> The other option is to only change 'ip -s link show' to use the new stats api. >> >> let me know if there are other thoughts. >> > > Is it not possible to convert to 64b - and IFLA_STAT > becomes available just store it still in 64b? > i.e 32b will fit in 64b space. The only problem is again if the last saved history file had 32 bit and 32bit counters may roll over earlier. One more thing i am looking at right now which might work is using the existing history file and use the info_source (aka header) in ifstat history file to indicate 32bit or 64bit stats. For 32 bit it is currently "#kernel". For 64 bit i plan to use "#kernel64". If we are starting a new history file, i will always use 64bit and when using an existing history file, it will use 32bit. And 64bit stats will be queried with RTM_GETSTATS if available or will use IFLA_STATS64 when RTM_NEWLINK Is used. will see if i can get this working for all cases, thanks, Roopa