linux-dev - Linux kernel development work

Age	Commit message (Collapse)	Author	Files	Lines
2013-05-20	rps: selective flow shedding during softnet overflow	Willem de Bruijn	1	-2/+14
	A cpu executing the network receive path sheds packets when its input queue grows to netdev_max_backlog. A single high rate flow (such as a spoofed source DoS) can exceed a single cpu processing rate and will degrade throughput of other flows hashed onto the same cpu. This patch adds a more fine grained hashtable. If the netdev backlog is above a threshold, IRQ cpus track the ratio of total traffic of each flow (using 4096 buckets, configurable). The ratio is measured by counting the number of packets per flow over the last 256 packets from the source cpu. Any flow that occupies a large fraction of this (set at 50%) will see packet drop while above the threshold. Tested: Setup is a muli-threaded UDP echo server with network rx IRQ on cpu0, kernel receive (RPS) on cpu0 and application threads on cpus 2--7 each handling 20k req/s. Throughput halves when hit with a 400 kpps antagonist storm. With this patch applied, antagonist overload is dropped and the server processes its complete load. The patch is effective when kernel receive processing is the bottleneck. The above RPS scenario is a extreme, but the same is reached with RFS and sufficient kernel processing (iptables, packet socket tap, ..). Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-25	net: Print functions in /proc/net/ptype without the offset.	David S. Miller	1	-1/+1
	It's always zero. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-27	hlist: drop the node parameter from iterators	Sasha Levin	1	-2/+1
	I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S \| hlist_for_each_entry_continue(a, - b, c) S \| hlist_for_each_entry_from(a, - b, c) S \| hlist_for_each_entry_rcu(a, - b, c, d) S \| hlist_for_each_entry_rcu_bh(a, - b, c, d) S \| hlist_for_each_entry_continue_rcu_bh(a, - b, c) S \| for_each_busy_worker(a, c, - b, d) S \| ax25_uid_for_each(a, - b, c) S \| ax25_for_each(a, - b, c) S \| inet_bind_bucket_for_each(a, - b, c) S \| sctp_for_each_hentry(a, - b, c) S \| sk_for_each(a, - b, c) S \| sk_for_each_rcu(a, - b, c) S \| sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S \| sk_for_each_safe(a, - b, c, d) S \| sk_for_each_bound(a, - b, c) S \| hlist_for_each_entry_safe(a, - b, c, d, e) S \| hlist_for_each_entry_continue_rcu(a, - b, c) S \| nr_neigh_for_each(a, - b, c) S \| nr_neigh_for_each_safe(a, - b, c, d) S \| nr_node_for_each(a, - b, c) S \| nr_node_for_each_safe(a, - b, c, d) S \| - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S \| - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S \| for_each_host(a, - b, c) S \| for_each_host_safe(a, - b, c, d) S \| for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-19	net: fix a build failure when !CONFIG_PROC_FS	Cong Wang	1	-7/+5
	When !CONFIG_PROC_FS dev_mcast_init() is not defined, actually we can just merge dev_mcast_init() into dev_proc_init(). Reported-by: Gao feng <gaofeng@cn.fujitsu.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19	net: move procfs code to net/core/net-procfs.c	Cong Wang	1	-0/+414
	Similar to net/core/net-sysfs.c, group procfs code to a single unit. Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>