All of lore.kernel.org
 help / color / mirror / Atom feed
From: "David Laight" <David.Laight@ACULAB.COM>
To: "Eric Dumazet" <eric.dumazet@gmail.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Cc: "Jason Wang" <jasowang@redhat.com>, <davem@davemloft.net>,
	<edumazet@google.com>, <hkchu@google.com>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: RE: [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array
Date: Wed, 19 Jun 2013 17:06:21 +0100	[thread overview]
Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6026B729A@saturn3.aculab.com> (raw)
In-Reply-To: <1371657511.3252.324.camel@edumazet-glaptop>

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 987 bytes --]

> +static void netif_free_tx_queues(struct net_device *dev)
> +{
> +	if (is_vmalloc_addr(dev->_tx))
> +		vfree(dev->_tx);
> +	else
> +		kfree(dev->_tx);
> +}
> +
>  static int netif_alloc_netdev_queues(struct net_device *dev)
>  {
>  	unsigned int count = dev->num_tx_queues;
> @@ -5261,9 +5270,11 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
>  	BUG_ON(count < 1);
> 
>  	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
> -	if (!tx)
> -		return -ENOMEM;
> -
> +	if (!tx) {
> +		tx = vzalloc(count * sizeof(struct netdev_queue));
> +		if (!tx)
> +			return -ENOMEM;
> +	}
>  	dev->_tx = tx;

Given the number of places I've seen this code added, why
not put it in a general helper?

I also thought that malloc() with GFP_KERNEL would sleep.
Under what conditions does it fail instead?

	David

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

WARNING: multiple messages have this Message-ID (diff)
From: "David Laight" <David.Laight@ACULAB.COM>
To: "Eric Dumazet" <eric.dumazet@gmail.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Cc: "Jason Wang" <jasowang@redhat.com>, <davem@davemloft.net>,
	<edumazet@google.com>, <hkchu@google.com>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: RE: [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array
Date: Wed, 19 Jun 2013 17:06:21 +0100	[thread overview]
Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6026B729A@saturn3.aculab.com> (raw)
In-Reply-To: <1371657511.3252.324.camel@edumazet-glaptop>

> +static void netif_free_tx_queues(struct net_device *dev)
> +{
> +	if (is_vmalloc_addr(dev->_tx))
> +		vfree(dev->_tx);
> +	else
> +		kfree(dev->_tx);
> +}
> +
>  static int netif_alloc_netdev_queues(struct net_device *dev)
>  {
>  	unsigned int count = dev->num_tx_queues;
> @@ -5261,9 +5270,11 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
>  	BUG_ON(count < 1);
> 
>  	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
> -	if (!tx)
> -		return -ENOMEM;
> -
> +	if (!tx) {
> +		tx = vzalloc(count * sizeof(struct netdev_queue));
> +		if (!tx)
> +			return -ENOMEM;
> +	}
>  	dev->_tx = tx;

Given the number of places I've seen this code added, why
not put it in a general helper?

I also thought that malloc() with GFP_KERNEL would sleep.
Under what conditions does it fail instead?

	David


  reply	other threads:[~2013-06-19 16:16 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-19  5:40 [net-next rfc 0/3] increase the limit of tuntap queues Jason Wang
2013-06-19  5:40 ` [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array Jason Wang
2013-06-19  6:31   ` Eric Dumazet
2013-06-19  7:14     ` Jason Wang
2013-06-19  9:11     ` Michael S. Tsirkin
2013-06-19  9:56       ` Eric Dumazet
2013-06-19 12:22         ` Michael S. Tsirkin
2013-06-19 15:40         ` Michael S. Tsirkin
2013-06-19 15:58           ` Eric Dumazet
2013-06-19 16:06             ` David Laight [this message]
2013-06-19 16:06               ` David Laight
2013-06-19 16:28               ` Eric Dumazet
2013-06-19 18:07             ` Michael S. Tsirkin
2013-06-20  8:15               ` [PATCH net-next] net: allow large number of tx queues Eric Dumazet
2013-06-20  8:35                 ` Michael S. Tsirkin
2013-06-21  6:41                   ` Jason Wang
2013-06-21  7:12                     ` Eric Dumazet
2013-06-23 10:29                       ` Michael S. Tsirkin
2013-06-24  6:57                 ` David Miller
2013-06-20  5:14         ` [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array Jason Wang
2013-06-20  6:05           ` Eric Dumazet
2013-06-19  5:40 ` [net-next rfc 2/3] tuntap: reduce the size of tun_struct " Jason Wang
2013-06-19  5:40 ` [net-next rfc 3/3] tuntap: increase the max queues to 16 Jason Wang
2013-06-19  6:34   ` Eric Dumazet
2013-06-19  7:15     ` Jason Wang
2013-06-19 19:16     ` Jerry Chu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=AE90C24D6B3A694183C094C60CF0A2F6026B729A@saturn3.aculab.com \
    --to=david.laight@aculab.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=eric.dumazet@gmail.com \
    --cc=hkchu@google.com \
    --cc=jasowang@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.