From: Eric Dumazet <eric.dumazet@gmail.com>
To: Ben Hutchings <bhutchings@solarflare.com>
Cc: David Miller <davem@davemloft.net>,
netdev@vger.kernel.org, linux-net-drivers@solarflare.com
Subject: Re: [PATCH net-next 09/11] sfc: Prefetch RX skb header area
Date: Wed, 19 Jun 2013 15:56:21 -0700 [thread overview]
Message-ID: <1371682581.3252.353.camel@edumazet-glaptop> (raw)
In-Reply-To: <1371681557.1956.121.camel@bwh-desktop.uk.level5networks.com>
On Wed, 2013-06-19 at 23:39 +0100, Ben Hutchings wrote:
> You can't use build_skb() if you put multiple RX buffers in a page. See
> <1365805319.2791.18.camel@bwh-desktop.uk.solarflarecom.com>.
Well, you use small skb (used to have 64 bytes headroom and you changed
it to 128) and attach a frag on it, so anyway build_skb() brings
nothing.
I suspect you have a win on workloads with flood of rx, but on moderate
load sk_buff will be cold, so the cache adds latencies.
My feeling is that this kind of tradeoff should not be per driver.
next prev parent reply other threads:[~2013-06-19 22:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-19 22:16 Pull request: sfc-next 2013-06-19 Ben Hutchings
2013-06-19 22:17 ` [PATCH net-next 01/11] sfc: Fix EEH with legacy interrupts Ben Hutchings
2013-06-19 22:18 ` [PATCH net-next 02/11] sfc: Enable RX checksum offload for packets not handled by GRO Ben Hutchings
2013-06-19 22:18 ` [PATCH net-next 03/11] sfc: Increase size of RX SKB header area Ben Hutchings
2013-06-19 22:38 ` Eric Dumazet
2013-06-19 22:18 ` [PATCH net-next 04/11] sfc: Report software timestamping capabilities Ben Hutchings
2013-06-19 22:19 ` [PATCH net-next 05/11] sfc: Enable accelerated RFS on vlans Ben Hutchings
2013-06-19 22:19 ` [PATCH net-next 06/11] sfc: Define and set RX buffer flag for packets parsed as TCP Ben Hutchings
2013-06-19 22:19 ` [PATCH net-next 07/11] sfc: Do not pass non-TCP packets into GRO code Ben Hutchings
2013-06-19 22:56 ` Eric Dumazet
2013-06-19 23:18 ` Ben Hutchings
2013-06-19 22:20 ` [PATCH net-next 08/11] sfc: Implement RX SKB cache to improve latency Ben Hutchings
2013-06-19 22:20 ` [PATCH net-next 09/11] sfc: Prefetch RX skb header area Ben Hutchings
2013-06-19 22:36 ` Eric Dumazet
2013-06-19 22:39 ` Ben Hutchings
2013-06-19 22:56 ` Eric Dumazet [this message]
2013-06-19 23:10 ` Ben Hutchings
2013-06-19 22:21 ` [PATCH net-next 10/11] sfc: Fix IRQ cleanup in case of a probe failure Ben Hutchings
2013-06-19 22:21 ` [PATCH net-next 11/11] sfc: Improve test for IOMMU in use Ben Hutchings
2013-06-19 23:11 ` Pull request: sfc-next 2013-06-19 David Miller
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