From: Eric Dumazet <eric.dumazet@gmail.com>
To: Chris Metcalf <cmetcalf@tilera.com>
Cc: bhutchings@solarflare.com, arnd@arndb.de,
David Miller <davem@davemloft.net>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH v9] tilegx network driver: initial support
Date: Wed, 06 Jun 2012 19:40:59 +0200 [thread overview]
Message-ID: <1339004459.26966.31.camel@edumazet-glaptop> (raw)
In-Reply-To: <201206042023.q54KNEZp003834@farm-0002.internal.tilera.com>
On Mon, 2012-06-04 at 16:12 -0400, Chris Metcalf wrote:
> +/* Allocate and push a buffer. */
> +static bool tile_net_provide_buffer(bool small)
> +{
> + int stack = small ? small_buffer_stack : large_buffer_stack;
> + const unsigned long buffer_alignment = 128;
> + struct sk_buff *skb;
> + int len;
> +
> + len = sizeof(struct sk_buff **) + buffer_alignment;
> + len += (small ? 128 : 1664);
1664 is a magic number, it should be a nice define
#define ..... ( ETH_DATA_LEN + .... )
> + skb = dev_alloc_skb(len);
> + if (skb == NULL)
> + return false;
> +
> + /* Make room for a back-pointer to 'skb' and guarantee alignment. */
> + skb_reserve(skb, sizeof(struct sk_buff **));
> + skb_reserve(skb, -(long)skb->data & (buffer_alignment - 1));
> +
> + /* Save a back-pointer to 'skb'. */
> + *(struct sk_buff **)(skb->data - sizeof(struct sk_buff **)) = skb;
> +
> + /* Make sure "skb" and the back-pointer have been flushed. */
> + wmb();
Interesting, have you considered using build_skb() instead of this
convoluted thing ?
This could save some cache misses...
next prev parent reply other threads:[~2012-06-06 17:41 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-04 20:39 [PATCH 0/6] arch/tile: provide tilegx networking support Chris Metcalf
2012-04-04 20:39 ` [PATCH 1/6] arch/tile: introduce GXIO IORPC framework for tilegx Chris Metcalf
2012-04-04 20:58 ` [PATCH 4/6] arch/tile: common DMA code for the GXIO IORPC subsystem Chris Metcalf
2012-04-06 17:41 ` [PATCH 2/6] arch/tile: fix set_pte() to properly handle kernel MMIO mappings Chris Metcalf
2012-04-06 17:52 ` [PATCH 3/6] arch/tile: support MMIO-based readb/writeb etc Chris Metcalf
2012-04-09 13:24 ` Arnd Bergmann
2012-04-09 20:53 ` Chris Metcalf
2012-04-06 20:38 ` [PATCH 5/6] arch/tile: provide kernel support for the tilegx mPIPE shim Chris Metcalf
2012-04-09 13:34 ` Arnd Bergmann
2012-04-09 21:04 ` Chris Metcalf
2012-04-06 20:42 ` [PATCH 6/6] tilegx network driver: initial support Chris Metcalf
2012-04-09 13:49 ` Arnd Bergmann
2012-04-09 21:30 ` Chris Metcalf
2012-04-10 10:42 ` Arnd Bergmann
2012-04-12 23:23 ` Chris Metcalf
2012-04-13 10:34 ` Arnd Bergmann
2012-04-28 22:07 ` Chris Metcalf
2012-04-04 20:39 ` [PATCH v2 0/6] arch/tile: networking support for tilegx Chris Metcalf
2012-04-04 20:39 ` [PATCH v2 1/6] arch/tile: introduce GXIO IORPC framework " Chris Metcalf
2012-04-04 20:58 ` [PATCH v2 3/6] arch/tile: common DMA code for the GXIO IORPC subsystem Chris Metcalf
2012-04-06 17:52 ` [PATCH v2 2/6] arch/tile: support MMIO-based readb/writeb etc Chris Metcalf
2012-04-06 20:38 ` [PATCH v2 4/6] arch/tile: provide kernel support for the tilegx mPIPE shim Chris Metcalf
2012-04-06 20:42 ` [PATCH v2 6/6] tilegx network driver: initial support Chris Metcalf
2012-04-30 14:35 ` Arnd Bergmann
2001-09-17 4:00 ` [PATCH v3] " Chris Metcalf
2012-05-03 5:41 ` David Miller
2012-05-03 15:45 ` Chris Metcalf
2012-05-03 17:07 ` David Miller
2012-05-03 17:25 ` Chris Metcalf
2012-05-03 16:41 ` [PATCH v4] " Chris Metcalf
2012-05-04 6:42 ` David Miller
2012-05-09 10:42 ` [PATCH v5] " Chris Metcalf
2012-05-11 13:54 ` Ben Hutchings
2012-05-20 4:42 ` [PATCH v6] " Chris Metcalf
2012-05-20 20:55 ` David Miller
2012-05-23 20:42 ` [PATCH v7] " Chris Metcalf
2012-05-24 4:31 ` David Miller
2012-05-25 14:42 ` [PATCH v8] " Chris Metcalf
2012-06-04 20:12 ` [PATCH v9] " Chris Metcalf
2012-06-06 16:41 ` David Miller
2012-06-06 17:31 ` Eric Dumazet
2012-06-06 17:40 ` Eric Dumazet [this message]
2012-06-06 18:36 ` Chris Metcalf
2012-06-06 18:54 ` David Miller
2001-09-17 4:00 ` [PATCH v10] " Chris Metcalf
2012-04-06 20:42 ` Chris Metcalf
2012-06-07 20:39 ` David Miller
2012-06-07 20:44 ` Chris Metcalf
2012-06-07 20:47 ` Chris Metcalf
2012-06-07 20:50 ` Ben Hutchings
2012-06-07 20:52 ` Joe Perches
2012-06-07 20:45 ` Chris Metcalf
2012-06-12 0:03 ` David Miller
2012-06-12 13:14 ` Chris Metcalf
2012-06-06 18:10 ` [PATCH v9] " Eric Dumazet
2012-06-06 18:17 ` David Miller
2012-06-06 18:19 ` Ben Hutchings
2012-05-20 16:35 ` [PATCH v5] " Chris Metcalf
2012-04-28 19:41 ` [PATCH v2 5/6] arch/tile: break out the "csum a long" function to <asm/checksum.h> Chris Metcalf
2012-04-29 11:15 ` [PATCH 6/6] tilegx network driver: initial support Arnd Bergmann
2012-04-15 23:06 ` Chris Metcalf
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