linux-kernel - Re: [PATCH net v3] lan743x: fix rx_napi

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] [day] [month] [year] [list]

Date:   Tue, 15 Dec 2020 10:33:30 -0500
From:   Sven Van Asbroeck <thesven73@...il.com>
To:     Bryan Whitehead <bryan.whitehead@...rochip.com>,
        Microchip Linux Driver Support <UNGLinuxDriver@...rochip.com>,
        David S Miller <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     Andrew Lunn <andrew@...n.ch>, Eric Dumazet <edumazet@...gle.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        netdev <netdev@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net v3] lan743x: fix rx_napi_poll/interrupt ping-pong

Hi Jakub,

On Fri, Dec 11, 2020 at 9:38 AM Sven Van Asbroeck <thesven73@...il.com> wrote:
>
> From: Sven Van Asbroeck <thesven73@...il.com>
>
> Even if there is more rx data waiting on the chip, the rx napi poll fn
> will never run more than once - it will always read a few buffers, then
> bail out and re-arm interrupts. Which results in ping-pong between napi
> and interrupt.
>
> This defeats the purpose of napi, and is bad for performance.
>
> Fix by making the rx napi poll behave identically to other ethernet
> drivers:

I was wondering if maybe you had any lingering doubts about this patch?
Is there anything I can do to address these?