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Date: Fri, 24 Oct 2014 13:31:40 +0400
From: "Alexander V. Chernikov" <melifaro@FreeBSD.org>
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To: Mateusz Guzik <mjguzik@gmail.com>, freebsd-net@freebsd.org
Subject: Re: nd6_timer vs Giant vs locking in general
References: <20141024052656.GG11222@dft-labs.eu>
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On 24.10.2014 09:26, Mateusz Guzik wrote:
> Hello there,
>
> dtrace revealed that the kernel schedules nd6_timer a lot. Not only
> that, his callout is not mpsafe so the kernel locks Giant which I
> believe is an oversight.
>
> Also the code looks really suspicious as it walks V_in6_ifaddrhead
> without any locking (not to mention there is an interestng comment:
> XXXRW: in6_ifaddrhead locking :>)
Yes, I'm going to fix some issues there after writing proper API.
ND changes are in https://reviews.freebsd.org/D903 .
>
> Dropping it here in case there is someone interested in fixing this up.
>