From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 23 Jan 2019 17:09:13 +0000 (+0100)
Subject: 4.4-stable patches
X-Git-Tag: v4.20.5~14
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=24f7b39c7504fde3c13ec4ebe3486140a0d5a157;p=thirdparty%2Fkernel%2Fstable-queue.git

4.4-stable patches

added patches:
	net-speed-up-skb_rbtree_purge.patch
---

diff --git a/queue-4.4/net-speed-up-skb_rbtree_purge.patch b/queue-4.4/net-speed-up-skb_rbtree_purge.patch
new file mode 100644
index 00000000000..841d2449649
--- /dev/null
+++ b/queue-4.4/net-speed-up-skb_rbtree_purge.patch
@@ -0,0 +1,52 @@
+From 7c90584c66cc4b033a3b684b0e0950f79e7b7166 Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Sat, 23 Sep 2017 12:39:12 -0700
+Subject: net: speed up skb_rbtree_purge()
+
+From: Eric Dumazet <edumazet@google.com>
+
+commit 7c90584c66cc4b033a3b684b0e0950f79e7b7166 upstream.
+
+As measured in my prior patch ("sch_netem: faster rb tree removal"),
+rbtree_postorder_for_each_entry_safe() is nice looking but much slower
+than using rb_next() directly, except when tree is small enough
+to fit in CPU caches (then the cost is the same)
+
+Also note that there is not even an increase of text size :
+$ size net/core/skbuff.o.before net/core/skbuff.o
+   text	   data	    bss	    dec	    hex	filename
+  40711	   1298	      0	  42009	   a419	net/core/skbuff.o.before
+  40711	   1298	      0	  42009	   a419	net/core/skbuff.o
+
+From: Eric Dumazet <edumazet@google.com>
+
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Mao Wenan <maowenan@huawei.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ net/core/skbuff.c |   11 +++++++----
+ 1 file changed, 7 insertions(+), 4 deletions(-)
+
+--- a/net/core/skbuff.c
++++ b/net/core/skbuff.c
+@@ -2388,12 +2388,15 @@ EXPORT_SYMBOL(skb_queue_purge);
+  */
+ void skb_rbtree_purge(struct rb_root *root)
+ {
+-	struct sk_buff *skb, *next;
++	struct rb_node *p = rb_first(root);
+ 
+-	rbtree_postorder_for_each_entry_safe(skb, next, root, rbnode)
+-		kfree_skb(skb);
++	while (p) {
++		struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
+ 
+-	*root = RB_ROOT;
++		p = rb_next(p);
++		rb_erase(&skb->rbnode, root);
++		kfree_skb(skb);
++	}
+ }
+ 
+ /**
diff --git a/queue-4.4/series b/queue-4.4/series
index 55602122ceb..f72c0e3aac8 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -100,3 +100,4 @@ scsi-megaraid-fix-out-of-bound-array-accesses.patch
 ocfs2-fix-panic-due-to-unrecovered-local-alloc.patch
 mm-page-writeback.c-don-t-break-integrity-writeback-.patch
 mm-proc-be-more-verbose-about-unstable-vma-flags-in-.patch
+net-speed-up-skb_rbtree_purge.patch