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* [Q] LL_RESERVED_SPACE(dev) vs HH_DATA_ALIGN(dev->hard_header_len)
@ 2004-02-08 11:39 YOSHIFUJI Hideaki / 吉藤英明
  2004-02-08 21:03 ` David S. Miller
  0 siblings, 1 reply; 2+ messages in thread
From: YOSHIFUJI Hideaki / 吉藤英明 @ 2004-02-08 11:39 UTC (permalink / raw)
  To: davem, kuznet; +Cc: netdev

Hello.

There're many places like:
  (dev->hard_header_len + 15) & ~15
or
  dev->hard_header_len + 15.

I guess the second one trying to express maximum number of the 
first one and it seems that
  HH_DATA_ALIGN(dev->hard_header_len)
  LL_SPACE_RESERVED(dev)
(defined in include/linux/netdevice.h) will do for us respectively.

Question: 
  How do you think about the following patch?
  Or, is it okay to simply use LL_RESERVED_SPACE(dev) in both places?

Thanks in advance.

===== net/econet/af_econet.c 1.30 vs edited =====
--- 1.30/net/econet/af_econet.c	Mon Jan 26 04:05:06 2004
+++ edited/net/econet/af_econet.c	Sun Feb  8 17:18:51 2004
@@ -318,12 +318,12 @@
 #ifdef CONFIG_ECONET_NATIVE
 		dev_hold(dev);
 		
-		skb = sock_alloc_send_skb(sk, len+dev->hard_header_len+15, 
+		skb = sock_alloc_send_skb(sk, len + LL_RESERVED_SPACE(dev),
 					  msg->msg_flags & MSG_DONTWAIT, &err);
 		if (skb==NULL)
 			goto out_unlock;
 		
-		skb_reserve(skb, (dev->hard_header_len+15)&~15);
+		skb_reserve(skb, HH_DATA_ALIGN(dev->hard_header_len));
 		skb->nh.raw = skb->data;
 		
 		eb = (struct ec_cb *)&skb->cb;

-- 
Hideaki YOSHIFUJI @ USAGI Project <yoshfuji@linux-ipv6.org>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF  80D8 4807 F894 E062 0EEA

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [Q] LL_RESERVED_SPACE(dev) vs HH_DATA_ALIGN(dev->hard_header_len)
  2004-02-08 11:39 [Q] LL_RESERVED_SPACE(dev) vs HH_DATA_ALIGN(dev->hard_header_len) YOSHIFUJI Hideaki / 吉藤英明
@ 2004-02-08 21:03 ` David S. Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David S. Miller @ 2004-02-08 21:03 UTC (permalink / raw)
  To: yoshfuji; +Cc: kuznet, netdev

On Sun, 08 Feb 2004 20:39:30 +0900 (JST)
YOSHIFUJI Hideaki / ^[$B5HF#1QL@^[(B <yoshfuji@linux-ipv6.org> wrote:

> Question: 
>   How do you think about the following patch?
>   Or, is it okay to simply use LL_RESERVED_SPACE(dev) in both places?

LL_RESERVED_SPACE() is what should be used in both spots.

I checked in the following patch, thanks for noticing this.

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2004/02/08 12:58:29-08:00 davem@nuts.davemloft.net 
#   [ECONET]: Use LL_RESERVED_SPACE() where applicable.  Noticed by yoshfuji.
# 
# net/econet/af_econet.c
#   2004/02/08 12:58:13-08:00 davem@nuts.davemloft.net +2 -2
#   [ECONET]: Use LL_RESERVED_SPACE() where applicable.  Noticed by yoshfuji.
# 
diff -Nru a/net/econet/af_econet.c b/net/econet/af_econet.c
--- a/net/econet/af_econet.c	Sun Feb  8 12:59:08 2004
+++ b/net/econet/af_econet.c	Sun Feb  8 12:59:08 2004
@@ -318,12 +318,12 @@
 #ifdef CONFIG_ECONET_NATIVE
 		dev_hold(dev);
 		
-		skb = sock_alloc_send_skb(sk, len+dev->hard_header_len+15, 
+		skb = sock_alloc_send_skb(sk, len+LL_RESERVED_SPACE(dev), 
 					  msg->msg_flags & MSG_DONTWAIT, &err);
 		if (skb==NULL)
 			goto out_unlock;
 		
-		skb_reserve(skb, (dev->hard_header_len+15)&~15);
+		skb_reserve(skb, LL_RESERVED_SPACE(dev));
 		skb->nh.raw = skb->data;
 		
 		eb = (struct ec_cb *)&skb->cb;

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2004-02-08 11:39 [Q] LL_RESERVED_SPACE(dev) vs HH_DATA_ALIGN(dev->hard_header_len) YOSHIFUJI Hideaki / 吉藤英明
2004-02-08 21:03 ` David S. Miller

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