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  1. 29 4月, 2007 1 次提交
  3. 26 4月, 2007 8 次提交
  5. 17 3月, 2007 1 次提交
  7. 27 2月, 2007 1 次提交
  9. 11 2月, 2007 1 次提交
  11. 09 2月, 2007 1 次提交
    • E
      [NET]: change layout of ehash table · dbca9b27
      由 Eric Dumazet 提交于 
      ehash table layout is currently this one :

First half of this table is used by sockets not in TIME_WAIT state
Second half of it is used by sockets in TIME_WAIT state.

This is non optimal because of for a given hash or socket, the two chain heads 
are located in separate cache lines.
Moreover the locks of the second half are never used.

If instead of this halving, we use two list heads in inet_ehash_bucket instead 
of only one, we probably can avoid one cache miss, and reduce ram usage, 
particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK, 
CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep 
together related chains to speedup lookups and socket state change.

In this patch I did not try to align struct inet_ehash_bucket, but a future 
patch could try to make this structure have a convenient size (a power of two 
or a multiple of L1_CACHE_SIZE).
I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so 
maybe we dont need to scratch our heads to align the bucket...

Note : In case struct inet_ehash_bucket is not a power of two, we could 
probably change alloc_large_system_hash() (in case it use __get_free_pages()) 
to free the unused space. It currently allocates a big zone, but the last 
quarter of it could be freed. Again, this should be a temporary 'problem'.

Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dbca9b27
  13. 14 12月, 2006 1 次提交
  15. 03 12月, 2006 4 次提交
  17. 16 11月, 2006 1 次提交
  19. 08 11月, 2006 1 次提交
  21. 23 9月, 2006 4 次提交
  23. 03 8月, 2006 2 次提交
  25. 04 7月, 2006 1 次提交
  27. 01 7月, 2006 4 次提交
  29. 30 6月, 2006 1 次提交
    • H
      [NET]: Added GSO header verification · 576a30eb
      由 Herbert Xu 提交于 
      When GSO packets come from an untrusted source (e.g., a Xen guest domain),
we need to verify the header integrity before passing it to the hardware.

Since the first step in GSO is to verify the header, we can reuse that
code by adding a new bit to gso_type: SKB_GSO_DODGY.  Packets with this
bit set can only be fed directly to devices with the corresponding bit
NETIF_F_GSO_ROBUST.  If the device doesn't have that bit, then the skb
is fed to the GSO engine which will allow the packet to be sent to the
hardware if it passes the header check.

This patch changes the sg flag to a full features flag.  The same method
can be used to implement TSO ECN support.  We simply have to mark packets
with CWR set with SKB_GSO_ECN so that only hardware with a corresponding
NETIF_F_TSO_ECN can accept them.  The GSO engine can either fully segment
the packet, or segment the first MTU and pass the rest to the hardware for
further segmentation.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      576a30eb
  31. 26 6月, 2006 1 次提交
    • H
      [NET]: Fix CHECKSUM_HW GSO problems. · 0718bcc0
      由 Herbert Xu 提交于 
      Fix checksum problems in the GSO code path for CHECKSUM_HW packets.

The ipv4 TCP pseudo header checksum has to be adjusted for GSO
segmented packets.

The adjustment is needed because the length field in the pseudo-header
changes.  However, because we have the inequality oldlen > newlen, we
know that delta = (u16)~oldlen + newlen is still a 16-bit quantity.
This also means that htonl(delta) + th->check still fits in 32 bits.
Therefore we don't have to use csum_add on this operations.

This is based on a patch by Michael Chan <mchan@broadcom.com>.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0718bcc0
  33. 23 6月, 2006 2 次提交
    • H
      [NET]: Add software TSOv4 · f4c50d99
      由 Herbert Xu 提交于 
      This patch adds the GSO implementation for IPv4 TCP.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f4c50d99
    • H
      [NET]: Merge TSO/UFO fields in sk_buff · 7967168c
      由 Herbert Xu 提交于 
      Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7967168c
  35. 18 6月, 2006 4 次提交
  37. 04 5月, 2006 1 次提交
    • H
      [TCP]: Fix sock_orphan dead lock · 75c2d907
      由 Herbert Xu 提交于 
      Calling sock_orphan inside bh_lock_sock in tcp_close can lead to dead
locks.  For example, the inet_diag code holds sk_callback_lock without
disabling BH.  If an inbound packet arrives during that admittedly tiny
window, it will cause a dead lock on bh_lock_sock.  Another possible
path would be through sock_wfree if the network device driver frees the
tx skb in process context with BH enabled.

We can fix this by moving sock_orphan out of bh_lock_sock.

The tricky bit is to work out when we need to destroy the socket
ourselves and when it has already been destroyed by someone else.

By moving sock_orphan before the release_sock we can solve this
problem.  This is because as long as we own the socket lock its
state cannot change.

So we simply record the socket state before the release_sock
and then check the state again after we regain the socket lock.
If the socket state has transitioned to TCP_CLOSE in the time being,
we know that the socket has been destroyed.  Otherwise the socket is
still ours to keep.

Note that I've also moved the increment on the orphan count forward.
This may look like a problem as we're increasing it even if the socket
is just about to be destroyed where it'll be decreased again.  However,
this simply enlarges a window that already exists.  This also changes
the orphan count test by one.

Considering what the orphan count is meant to do this is no big deal.

This problem was discoverd by Ingo Molnar using his lock validator.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      75c2d907