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From: Jonathan Morton <chromatix99@gmail.com>
To: cake@lists.bufferbloat.net
Subject: Re: [Cake] Heaps of cake
Date: Sun, 29 May 2016 05:32:22 +0300	[thread overview]
Message-ID: <DDED267A-3FC4-4E00-A141-950F6EFCB5DE@gmail.com> (raw)
In-Reply-To: <D3D26D03-39C9-4B0D-A61A-886FC9E626CB@gmail.com>


> On 21 May, 2016, at 01:07, Jonathan Morton <chromatix99@gmail.com> wrote:
> 
> Please do hammer on these codepaths for all you’re worth.  It compiles and survives a smoke-test, that’s all I know so far.

Having noted a series of kernel panics in cake_drop(), I eventually traced the fault to dequeue_head(), which AFAIK hadn’t been touched since the first version (as it was lifted from fq_codel).  If it’s called on en empty subqueue, it tried to read NULL->next.

The question remains why cake_drop() would select an empty subqueue as the longest one - evidently there’s a missing heap update somewhere.  But at least now it won’t crash if that happens.

 - Jonathan Morton


  reply	other threads:[~2016-05-29  2:32 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-20 22:07 Jonathan Morton
2016-05-29  2:32 ` Jonathan Morton [this message]
2016-05-29 15:51   ` Kevin Darbyshire-Bryant

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