[PATCH 0/2] remove truesize workarounds

[PATCH 0/2] remove truesize workarounds

[Johannes Berg]

The truesize mangling and orphaning of the skb
are workarounds for the old skb_truesize_check
that was really just checking the wrong thing;
davem removed that check a while ago.

johannes

[PATCH 1/2] mac80211: dont adjust truesize

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

There's no need to adjust truesize.

The history of this was that we always ran into
skb_truesize_bug (via skb_truesize_check) which
has since been removed in commit 92a0acce186cd.
skb_truesize_check() checked that truesize  was
bigger or equal to the actual allocation, which
would trigger in mac80211 due to header adding.
The check no longer exists and we shouldn't be
messing with the truesize anwyay.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/tx.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/net/mac80211/tx.c	2011-10-07 14:50:23.000000000 +0200
+++ b/net/mac80211/tx.c	2011-10-07 14:50:27.000000000 +0200
@@ -1402,9 +1402,6 @@ static int ieee80211_skb_resize(struct i
 		return -ENOMEM;
 	}
 
-	/* update truesize too */
-	skb->truesize += head_need + tail_need;
-
 	return 0;
 }
 

[PATCH 2/2] mac80211: dont orphan TX skb

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

This was another workaround for truesize "bugs".
The reason we did this was that when we orphaned
the SKB it wouldn't be truesize-checked later.
Now that the check is gone (and we just charge
the former smaller size to the socket) there's
no longer a reason to orphan the skb here.

Keep the skb charged to the socket until it is
really freed (or orphaned in TX status). This
helps flow control and allows us to get at the
socket later for other purposes.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/tx.c |    5 -----
 1 file changed, 5 deletions(-)

--- a/net/mac80211/tx.c	2011-10-07 14:50:27.000000000 +0200
+++ b/net/mac80211/tx.c	2011-10-07 14:50:30.000000000 +0200
@@ -1384,11 +1384,6 @@ static int ieee80211_skb_resize(struct i
 		tail_need = max_t(int, tail_need, 0);
 	}
 
-	if (head_need || tail_need) {
-		/* Sorry. Can't account for this any more */
-		skb_orphan(skb);
-	}
-
 	if (skb_cloned(skb))
 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
 	else if (head_need || tail_need)