Skip to content

L
linux
Switch branch/tag
  1. 24 Jun, 2013 33 commits
  3. 21 Jun, 2013 1 commit
  5. 20 Jun, 2013 6 commits
    • Joe Perches's avatar
      ndisc: Convert use of typedef ctl_table to struct ctl_table · fedaf4ff
      Joe Perches authored 
      This typedef is unnecessary and should just be removed.
Signed-off-by: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fedaf4ff
    • Joe Perches's avatar
      ipv6: Convert use of typedef ctl_table to struct ctl_table · 9e8cda3b
      Joe Perches authored 
      This typedef is unnecessary and should just be removed.
Signed-off-by: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9e8cda3b
    • Rami Rosen's avatar
      inet: frag , remove an empty ifdef. · af92e542
      Rami Rosen authored 
      This patch removes an empty ifdef from inet_frag_intern()
in net/ipv4/inet_fragment.c.

commit b67bfe0d
(hlist: drop the node parameter from iterators) removed hlist from
net/ipv4/inet_fragment.c, but did not remove the enclosing ifdef command,
which is now empty.
Signed-off-by: default avatarRami Rosen <ramirose@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      af92e542
    • Eric Dumazet's avatar
      htb: refactor struct htb_sched fields for performance · c9364636
      Eric Dumazet authored 
      htb_sched structures are big, and source of false sharing on SMP.

Every time a packet is queued or dequeue, many cache lines must be
touched because structures are not lay out properly.

By carefully splitting htb_sched in two parts, and define sub structures
to increase data locality, we can improve performance dramatically on
SMP.

New htb_prio structure can also be used in htb_class to increase data
locality.

I got 26 % performance increase on a 24 threads machine, with 200
concurrent netperf in TCP_RR mode, using a HTB hierarchy of 4 classes.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c9364636
    • Cong Wang's avatar
      tcp: introduce a per-route knob for quick ack · bcefe17c
      Cong Wang authored 
      In previous discussions, I tried to find some reasonable heuristics
for delayed ACK, however this seems not possible, according to Eric:

	"ACKS might also be delayed because of bidirectional
	traffic, and is more controlled by the application
	response time. TCP stack can not easily estimate it."

	"ACK can be incredibly useful to recover from losses in
	a short time.

	The vast majority of TCP sessions are small lived, and we
	send one ACK per received segment anyway at beginning or
	retransmits to let the sender smoothly increase its cwnd,
	so an auto-tuning facility wont help them that much."

and according to David:

	"ACKs are the only information we have to detect loss.

	And, for the same reasons that TCP VEGAS is fundamentally
	broken, we cannot measure the pipe or some other
	receiver-side-visible piece of information to determine
	when it's "safe" to stretch ACK.

	And even if it's "safe", we should not do it so that losses are
	accurately detected and we don't spuriously retransmit.

	The only way to know when the bandwidth increases is to
	"test" it, by sending more and more packets until drops happen.
	That's why all successful congestion control algorithms must
	operate on explicited tested pieces of information.

	Similarly, it's not really possible to universally know if
	it's safe to stretch ACK or not."

It still makes sense to enable or disable quick ack mode like
what TCP_QUICK_ACK does.

Similar to TCP_QUICK_ACK option, but for people who can't
modify the source code and still wants to control
TCP delayed ACK behavior. As David suggested, this should belong
to per-path scope, since different pathes may want different
behaviors.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Rick Jones <rick.jones2@hp.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
CC: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: default avatarCong Wang <amwang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bcefe17c
    • Dave Jones's avatar
      sctp: Convert __list_for_each use to list_for_each · 2c0740e4
      Dave Jones authored 
      Signed-off-by: default avatarDave Jones <davej@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2c0740e4
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7