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From: Vladimir Oltean <vladimir.oltean@nxp.com>
To: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: "andrew@lunn.ch" <andrew@lunn.ch>,
	"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
	"vivien.didelot@gmail.com" <vivien.didelot@gmail.com>,
	"kuba@kernel.org" <kuba@kernel.org>,
	Christian Eggers <ceggers@arri.de>,
	Kurt Kanzenbach <kurt@linutronix.de>
Subject: Re: [RFC PATCH 02/13] net: dsa: implement a central TX reallocation procedure
Date: Sun, 18 Oct 2020 00:13:27 +0000
Message-ID: <20201018001326.auu4u7mgfnxk37nx@skbuf> (raw)
In-Reply-To: <20201017223120.em6bp245oyfuzepk@skbuf>

On Sun, Oct 18, 2020 at 01:31:20AM +0300, Vladimir Oltean wrote:
> On Sun, Oct 18, 2020 at 01:01:04AM +0300, Vladimir Oltean wrote:
> > > +	return pskb_expand_head(skb, headroom, tailroom, GFP_ATOMIC);
> > 	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > 	err = pskb_expand_head(skb, headroom, tailroom, GFP_ATOMIC);
> > 	if (err < 0 || !padlen)
> > 		return err;
> > 
> > 	return __skb_put_padto(skb, padlen, false);
> 
> Oops, another one here. Should be:
> 
> 	return __skb_put_padto(skb, skb->len + padlen, false);
> > > +}

Last one for today. This should actually be correct now, and not
allocate double the needed headroom size.

static int dsa_realloc_skb(struct sk_buff *skb, struct net_device *dev)
{
	struct dsa_slave_priv *p = netdev_priv(dev);
	struct dsa_slave_stats *e;
	int needed_headroom;
	int needed_tailroom;
	int padlen = 0, err;

	needed_headroom = dev->needed_headroom;
	needed_tailroom = dev->needed_tailroom;
	/* For tail taggers, we need to pad short frames ourselves, to ensure
	 * that the tail tag does not fail at its role of being at the end of
	 * the packet, once the master interface pads the frame.
	 */
	if (unlikely(needed_tailroom && skb->len < ETH_ZLEN))
		padlen = ETH_ZLEN - skb->len;
	needed_tailroom += padlen;
	needed_headroom -= skb_headroom(skb);
	needed_tailroom -= skb_tailroom(skb);

	if (likely(needed_headroom <= 0 && needed_tailroom <= 0 &&
		   !skb_cloned(skb)))
		/* No reallocation needed, yay! */
		return 0;

	e = this_cpu_ptr(p->extra_stats);
	u64_stats_update_begin(&e->syncp);
	e->tx_reallocs++;
	u64_stats_update_end(&e->syncp);

	err = pskb_expand_head(skb, max(needed_headroom, 0),
			       max(needed_tailroom, 0), GFP_ATOMIC);
	if (err < 0 || !padlen)
		return err;

	return __skb_put_padto(skb, ETH_ZLEN, false);
}

  reply index

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-17 21:35 [RFC PATCH 00/13] Generic TX reallocation for DSA Vladimir Oltean
2020-10-17 21:35 ` [RFC PATCH 01/13] net: dsa: add plumbing for custom netdev statistics Vladimir Oltean
2020-10-17 22:13   ` Florian Fainelli
2020-10-17 23:15   ` Andrew Lunn
2020-10-18  0:23     ` Vladimir Oltean
2020-10-18 12:02   ` Heiner Kallweit
2020-10-18 12:16     ` Vladimir Oltean
2020-10-18 13:09       ` Heiner Kallweit
2020-10-18 13:48         ` Vladimir Oltean
2020-10-18 14:13           ` Heiner Kallweit
2020-10-18 22:58             ` Vladimir Oltean
2020-10-18 23:11               ` Florian Fainelli
2020-10-19  0:21                 ` Vladimir Oltean
2020-10-19  3:49                   ` Florian Fainelli
2020-10-19 12:05                     ` Andrew Lunn
2020-10-19 16:27                       ` Florian Fainelli
2020-10-18 16:49   ` Jakub Kicinski
2020-10-18 17:36     ` Andrew Lunn
2020-10-18 18:26       ` Jakub Kicinski
2020-10-18 18:33         ` Jakub Kicinski
2020-10-17 21:36 ` [RFC PATCH 02/13] net: dsa: implement a central TX reallocation procedure Vladimir Oltean
2020-10-17 22:01   ` Vladimir Oltean
2020-10-17 22:11     ` Florian Fainelli
2020-10-17 22:17       ` Vladimir Oltean
2020-10-18  0:37         ` Florian Fainelli
2020-10-19  8:33       ` David Laight
2020-10-19 10:30         ` Vladimir Oltean
2020-10-19 11:14           ` David Laight
2020-10-19 11:41             ` Vladimir Oltean
2020-10-19 12:19           ` Andrew Lunn
2020-10-17 22:31     ` Vladimir Oltean
2020-10-18  0:13       ` Vladimir Oltean [this message]
2020-10-18 10:36         ` Christian Eggers
2020-10-18 11:42           ` Vladimir Oltean
2020-10-18 11:59             ` Christian Eggers
2020-10-18 12:15               ` Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 03/13] net: dsa: tag_ksz: don't allocate additional memory for padding/tagging Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 04/13] net: dsa: trailer: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 05/13] net: dsa: tag_qca: let DSA core deal with TX reallocation Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 06/13] net: dsa: tag_ocelot: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 07/13] net: dsa: tag_mtk: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 08/13] net: dsa: tag_lan9303: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 09/13] net: dsa: tag_edsa: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 10/13] net: dsa: tag_brcm: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 11/13] net: dsa: tag_dsa: " Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 12/13] net: dsa: tag_gswip: " Vladimir Oltean
2020-10-17 22:19   ` Vladimir Oltean
2020-10-17 21:36 ` [RFC PATCH 13/13] net: dsa: tag_ar9331: " Vladimir Oltean
2020-10-17 23:07 ` [RFC PATCH 00/13] Generic TX reallocation for DSA Andrew Lunn

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