From: Zoltan Kiss <zoltan.kiss@schaman•hu>
To: David Miller <davem@davemloft•net>
Cc: xen-devel@lists•xenproject.org, ian.campbell@citrix•com,
wei.liu2@citrix•com, paul.durrant@citrix•com,
linux@eikelenboom•it, netdev@vger•kernel.org,
david.vrabel@citrix•com
Subject: Re: [PATCH net] xen-netback: Fix slot estimation
Date: Fri, 06 Jun 2014 11:20:45 +0100 [thread overview]
Message-ID: <539195FD.6080606@schaman.hu> (raw)
In-Reply-To: <20140605.150209.365488173138758921.davem@davemloft.net>
On 05/06/14 23:02, David Miller wrote:
> From: Zoltan Kiss<zoltan.kiss@citrix•com>
> Date: Tue, 3 Jun 2014 14:32:16 +0100
>
>> A recent commit (a02eb4 "xen-netback: worse-case estimate in xenvif_rx_action is
>> underestimating") capped the slot estimation to MAX_SKB_FRAGS, but that triggers
>> the next BUG_ON a few lines down, as the packet consumes more slots than
>> estimated.
>> This patch remove that cap, and if the frontend doesn't provide enough slot,
>> put back the skb to the top of the queue and caps rx_last_skb_slots. When the
>> next try also fails, it drops the packet.
>> Capping rx_last_skb_slots is needed because if the frontend never gives enough
>> slots, the ring gets stalled.
>>
>> Signed-off-by: Zoltan Kiss<zoltan.kiss@citrix•com>
> Like David Laight, I do not like this patch at all.
>
> Yes a crash or BUG_ON triggered is bad, but fixing it by deadlocking
> TCP connections (a silent failure) is not an improvement.
>
> I'm not applying this, sorry.
>
Hi,
I haven't wrote it explicitly, but my other patch "xen-netback: Fix
handling of skbs requiring too many slots" supersedes this one.
next prev parent reply other threads:[~2014-06-06 10:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-03 13:32 [PATCH net] xen-netback: Fix slot estimation Zoltan Kiss
2014-06-03 13:37 ` Paul Durrant
2014-06-03 14:04 ` Zoltan Kiss
2014-06-03 13:52 ` David Laight
2014-06-03 20:24 ` Zoltan Kiss
2014-06-05 22:02 ` David Miller
2014-06-06 10:20 ` Zoltan Kiss [this message]
2014-06-06 20:06 ` David Miller
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