From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: haiyangz@microsoft.com, edumazet@google.com,
netdev@vger.kernel.org, kys@microsoft.com
Subject: Re: [PATCH v2 net-next] net: make skb_set_owner_w() more robust
Date: Mon, 02 Nov 2015 15:26:10 -0500 (EST) [thread overview]
Message-ID: <20151102.152610.2091248201809813226.davem@davemloft.net> (raw)
In-Reply-To: <1446494965.23275.28.camel@edumazet-glaptop2.roam.corp.google.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 02 Nov 2015 12:09:25 -0800
> On Mon, 2015-11-02 at 20:05 +0000, Haiyang Zhang wrote:
>
>> Thanks for the fix!
>> For some driver, like ours, this condition may not be "unlikely".
>> So could you remove the "unlikely"?
>
> No, I wont remove the unlikely.
>
> Look, your main issue is about reallocating skbs, because of excessive
> dev->needed_headroom.
>
> An unlikely() mismatch is 1000 times less expensive, why would you
> care ?
>
> If you really care, fix your driver to not abuse skb->head to store 220
> bytes of private data.
+1
And I've been saying this from the beginning. This driver must place
it's private per-packet data in another location if it wants optimal
behavior inside of the Linux networking stack.
next prev parent reply other threads:[~2015-11-02 20:26 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-29 21:49 [patch] tcp: attach SYNACK messages to request sockets instead of listener Haiyang Zhang
2015-10-29 22:58 ` Eric Dumazet
2015-10-30 19:38 ` Haiyang Zhang
2015-10-30 20:02 ` Eric Dumazet
2015-10-30 20:18 ` Eric Dumazet
2015-10-30 21:42 ` Haiyang Zhang
2015-10-30 23:52 ` Eric Dumazet
2015-11-01 17:20 ` [PATCH net-next] net: increase LL_MAX_HEADER if HYPERV_NET is enabled Eric Dumazet
2015-11-01 20:58 ` David Miller
2015-11-01 22:36 ` Eric Dumazet
2015-11-01 22:58 ` [PATCH net-next] net: make skb_set_owner_w() more robust Eric Dumazet
2015-11-01 23:18 ` kbuild test robot
2015-11-01 23:27 ` Eric Dumazet
2015-11-01 23:36 ` [PATCH v2 " Eric Dumazet
2015-11-02 20:05 ` Haiyang Zhang
2015-11-02 20:09 ` Eric Dumazet
2015-11-02 20:26 ` David Miller [this message]
2015-11-02 21:29 ` David Miller
2015-11-03 7:59 ` [PATCH net-next] net: increase LL_MAX_HEADER if HYPERV_NET is enabled KY Srinivasan
2015-11-03 15:33 ` David Miller
2015-11-03 16:37 ` Eric Dumazet
2015-11-03 17:34 ` Haiyang Zhang
2015-11-03 18:20 ` David Miller
2015-11-03 18:49 ` Haiyang Zhang
2015-11-03 19:50 ` David Miller
2015-11-03 21:00 ` Haiyang Zhang
2015-11-03 18:09 ` KY Srinivasan
2015-10-30 20:28 ` [patch] tcp: attach SYNACK messages to request sockets instead of listener KY Srinivasan
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