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  1. 11 11月, 2005 2 次提交
    • S
      [TCP]: fix congestion window update when using TSO deferal · f4805ede
      由 Stephen Hemminger 提交于 
      TCP peformance with TSO over networks with delay is awful.
On a 100Mbit link with 150ms delay, we get 4Mbits/sec with TSO and
50Mbits/sec without TSO.

The problem is with TSO, we intentionally do not keep the maximum
number of packets in flight to fill the window, we hold out to until 
we can send a MSS chunk. But, we also don't update the congestion window 
unless we have filled, as per RFC2861.

This patch replaces the check for the congestion window being full
with something smarter that accounts for TSO.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f4805ede
    • H
      [NET]: Detect hardware rx checksum faults correctly · fb286bb2
      由 Herbert Xu 提交于 
      Here is the patch that introduces the generic skb_checksum_complete
which also checks for hardware RX checksum faults.  If that happens,
it'll call netdev_rx_csum_fault which currently prints out a stack
trace with the device name.  In future it can turn off RX checksum.

I've converted every spot under net/ that does RX checksum checks to
use skb_checksum_complete or __skb_checksum_complete with the
exceptions of:

* Those places where checksums are done bit by bit.  These will call
netdev_rx_csum_fault directly.

* The following have not been completely checked/converted:

ipmr
ip_vs
netfilter
dccp

This patch is based on patches and suggestions from Stephen Hemminger
and David S. Miller.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fb286bb2
  3. 09 10月, 2005 1 次提交
  5. 02 9月, 2005 1 次提交
  7. 30 8月, 2005 22 次提交
  9. 31 7月, 2005 1 次提交
  11. 09 7月, 2005 2 次提交
  13. 06 7月, 2005 7 次提交
    • D
      [TCP]: Move to new TSO segmenting scheme. · c1b4a7e6
      由 David S. Miller 提交于 
      Make TSO segment transmit size decisions at send time not earlier.

The basic scheme is that we try to build as large a TSO frame as
possible when pulling in the user data, but the size of the TSO frame
output to the card is determined at transmit time.

This is guided by tp->xmit_size_goal.  It is always set to a multiple
of MSS and tells sendmsg/sendpage how large an SKB to try and build.

Later, tcp_write_xmit() and tcp_push_one() chop up the packet if
necessary and conditions warrant.  These routines can also decide to
"defer" in order to wait for more ACKs to arrive and thus allow larger
TSO frames to be emitted.

A general observation is that TSO elongates the pipe, thus requiring a
larger congestion window and larger buffering especially at the sender
side.  Therefore, it is important that applications 1) get a large
enough socket send buffer (this is accomplished by our dynamic send
buffer expansion code) 2) do large enough writes.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c1b4a7e6
    • D
      [TCP]: Fix __tcp_push_pending_frames() 'nonagle' handling. · 55c97f3e
      由 David S. Miller 提交于 
      'nonagle' should be passed to the tcp_snd_test() function
as 'TCP_NAGLE_PUSH' if we are checking an SKB not at the
tail of the write_queue.  This is because Nagle does not
apply to such frames since we cannot possibly tack more
data onto them.

However, while doing this __tcp_push_pending_frames() makes
all of the packets in the write_queue use this modified
'nonagle' value.

Fix the bug and simplify this function by just calling
tcp_write_xmit() directly if sk_send_head is non-NULL.

As a result, we can now make tcp_data_snd_check() just call
tcp_push_pending_frames() instead of the specialized
__tcp_data_snd_check().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      55c97f3e
    • D
      [TCP]: Fix redundant calculations of tcp_current_mss() · a2e2a59c
      由 David S. Miller 提交于 
      tcp_write_xmit() uses tcp_current_mss(), but some of it's callers,
namely __tcp_push_pending_frames(), already has this value available
already.

While we're here, fix the "cur_mss" argument to be "unsigned int"
instead of plain "unsigned".
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a2e2a59c
    • D
      [TCP]: Kill extra cwnd validate in __tcp_push_pending_frames(). · a762a980
      由 David S. Miller 提交于 
      The tcp_cwnd_validate() function should only be invoked
if we actually send some frames, yet __tcp_push_pending_frames()
will always invoke it.  tcp_write_xmit() does the call for us,
so the call here can simply be removed.

Also, tcp_write_xmit() can be marked static.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a762a980
    • D
      [TCP]: Move __tcp_data_snd_check into tcp_output.c · 84d3e7b9
      由 David S. Miller 提交于 
      It reimplements portions of tcp_snd_check(), so it
we move it to tcp_output.c we can consolidate it's
logic much easier in a later change.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      84d3e7b9
    • D
      [TCP]: Move send test logic out of net/tcp.h · f6302d1d
      由 David S. Miller 提交于 
      This just moves the code into tcp_output.c, no code logic changes are
made by this patch.

Using this as a baseline, we can begin to untangle the mess of
comparisons for the Nagle test et al.  We will also be able to reduce
all of the redundant computation that occurs when outputting data
packets.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f6302d1d
    • D
      [TCP]: Fix quick-ack decrementing with TSO. · fc6415bc
      由 David S. Miller 提交于 
      On each packet output, we call tcp_dec_quickack_mode()
if the ACK flag is set.  It drops tp->ack.quick until
it hits zero, at which time we deflate the ATO value.

When doing TSO, we are emitting multiple packets with
ACK set, so we should decrement tp->ack.quick that many
segments.

Note that, unlike this case, tcp_enter_cwr() should not
take the tcp_skb_pcount(skb) into consideration.  That
function, one time, readjusts tp->snd_cwnd and moves
into TCP_CA_CWR state.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fc6415bc
  15. 24 6月, 2005 3 次提交
  17. 19 6月, 2005 1 次提交