netdev - Re: [patch net-next v7 0/3] return offloaded stats as default and expose original sw stats

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <57CED9C7.3030803@cumulusnetworks.com>
Date:   Tue, 06 Sep 2016 07:59:19 -0700
From:   Roopa Prabhu <roopa@...ulusnetworks.com>
To:     Jiri Pirko <jiri@...nulli.us>
CC:     netdev@...r.kernel.org, davem@...emloft.net, nogahf@...lanox.com,
        idosch@...lanox.com, eladr@...lanox.com, yotamg@...lanox.com,
        ogerlitz@...lanox.com, nikolay@...ulusnetworks.com,
        linville@...driver.com, tgraf@...g.ch, gospo@...ulusnetworks.com,
        sfeldma@...il.com, sd@...asysnail.net, eranbe@...lanox.com,
        ast@...mgrid.com, edumazet@...gle.com, hannes@...essinduktion.org,
        f.fainelli@...il.com, dsa@...ulusnetworks.com
Subject: Re: [patch net-next v7 0/3] return offloaded stats as default and
 expose original sw stats

On 9/5/16, 10:18 AM, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@...lanox.com>
>
> The problem we try to handle is about offloaded forwarded packets
> which are not seen by kernel. Let me try to draw it:
>
>     port1                       port2 (HW stats are counted here)
>       \                          /
>        \                        /
>         \                      /
>          --(A)---- ASIC --(B)--
>                     |
>                    (C)
>                     |
>                    CPU (SW stats are counted here)
>
>
> Now we have couple of flows for TX and RX (direction does not matter here):
>
> 1) port1->A->ASIC->C->CPU
>
>    For this flow, HW and SW stats are equal.
>
> 2) port1->A->ASIC->C->CPU->C->ASIC->B->port2
>
>    For this flow, HW and SW stats are equal.
>
> 3) port1->A->ASIC->B->port2
>
>    For this flow, SW stats are 0.
>
> The purpose of this patchset is to provide facility for user to
> find out the difference between flows 1+2 and 3. In other words, user
> will be able to see the statistics for the slow-path (through kernel).
>
> Also note that HW stats are what someone calls "accumulated" stats.
> Every packet counted by SW is also counted by HW. Not the other way around.
>
> As a default the accumulated stats (HW) will be exposed to user
> so the userspace apps can react properly.
>
> This patchset add the SW stats (flows 1+2) under offload related stats, so
> in the future we can expose other offload related stat in a similar way.
>
> ---
>
Acked-by: Roopa Prabhu <roopa@...ulusnetworks.com>
few questions on the two ndo's on specific patches, but, the user api LGTM.

thanks jiri and nogah.