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  1. 24 1月, 2014 1 次提交
  3. 23 1月, 2014 33 次提交
  5. 22 1月, 2014 6 次提交
    • H
      reciprocal_divide: update/correction of the algorithm · 809fa972
      由 Hannes Frederic Sowa 提交于 
      Jakub Zawadzki noticed that some divisions by reciprocal_divide()
were not correct [1][2], which he could also show with BPF code
after divisions are transformed into reciprocal_value() for runtime
invariance which can be passed to reciprocal_divide() later on;
reverse in BPF dump ended up with a different, off-by-one K in
some situations.

This has been fixed by Eric Dumazet in commit aee636c4
("bpf: do not use reciprocal divide"). This follow-up patch
improves reciprocal_value() and reciprocal_divide() to work in
all cases by using Granlund and Montgomery method, so that also
future use is safe and without any non-obvious side-effects.
Known problems with the old implementation were that division by 1
always returned 0 and some off-by-ones when the dividend and divisor
where very large. This seemed to not be problematic with its
current users, as far as we can tell. Eric Dumazet checked for
the slab usage, we cannot surely say so in the case of flex_array.
Still, in order to fix that, we propose an extension from the
original implementation from commit 6a2d7a95 resp. [3][4],
by using the algorithm proposed in "Division by Invariant Integers
Using Multiplication" [5], Torbjörn Granlund and Peter L.
Montgomery, that is, pseudocode for q = n/d where q, n, d is in
u32 universe:

1) Initialization:

  int l = ceil(log_2 d)
  uword m' = floor((1<<32)*((1<<l)-d)/d)+1
  int sh_1 = min(l,1)
  int sh_2 = max(l-1,0)

2) For q = n/d, all uword:

  uword t = (n*m')>>32
  q = (t+((n-t)>>sh_1))>>sh_2

The assembler implementation from Agner Fog [6] also helped a lot
while implementing. We have tested the implementation on x86_64,
ppc64, i686, s390x; on x86_64/haswell we're still half the latency
compared to normal divide.

Joint work with Daniel Borkmann.

  [1] http://www.wireshark.org/~darkjames/reciprocal-buggy.c
  [2] http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c
  [3] https://gmplib.org/~tege/division-paper.pdf
  [4] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html
  [5] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1.2556
  [6] http://www.agner.org/optimize/asmlib.zipReported-by: NJakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Jesse Gross <jesse@nicira.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      809fa972
    • D
      random32: add prandom_u32_max and convert open coded users · f337db64
      由 Daniel Borkmann 提交于 
      Many functions have open coded a function that returns a random
number in range [0,N-1]. Under the assumption that we have a PRNG
such as taus113 with being well distributed in [0, ~0U] space,
we can implement such a function as uword t = (n*m')>>32, where
m' is a random number obtained from PRNG, n the right open interval
border and t our resulting random number, with n,m',t in u32 universe.

Lets go with Joe and simply call it prandom_u32_max(), although
technically we have an right open interval endpoint, but that we
have documented. Other users can further be migrated to the new
prandom_u32_max() function later on; for now, we need to make sure
to migrate reciprocal_divide() users for the reciprocal_divide()
follow-up fixup since their function signatures are going to change.

Joint work with Hannes Frederic Sowa.

Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f337db64
    • M
      net/mlx4_core: Remove unnecessary validation for port number · 6cd28f04
      由 Moni Shoua 提交于 
      This is a fix to a regression introduced by commit:
"982290a7 net/mlx4_core: Check port number for validity
before accessing data"

IPoIB could not attach to multicast group and we get this in dmesg:
[144214.145008] ib0: failed to attach to multicast group, ret = -22
[144214.145016] ib0: couldn't attach QP to multicast group ff12:401b:ffff:0000:0000:0000:ffff:ffff
[144214.145019] ib0: multicast join failed for ff12:401b:ffff:0000:0000:0000:ffff:ffff, status -22

The cause to the problem is because port is extracted from gid[5].
Which is only valid for Ethernet.
Removed this validation in mlx4_qp_attach_common(), which is accessed
from both Ethernet and IB flows.
Error flow for bad port value in Ethernet is already exists in that
function.
Signed-off-by: NMoni Shoua <monis@mellanox.co.il>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6cd28f04
    • S
      be2net: Fix be_vlan_add/rem_vid() routines · a6b74e01
      由 Somnath Kotur 提交于 
      The current logic to put interface into VLAN Promiscous mode is not correct.
We should increment "adapter->vlans_added" before calling be_vid_config().
Also removed some unwanted log messages.
Signed-off-by: NKalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: NSomnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a6b74e01
    • A
      bnx2x: Fix VF flr flow · 076d1329
      由 Ariel Elior 提交于 
      When a VF originating from a given PF is flr-ed, that PF gets an interrupt
from the chip management and takes a part in the flr process.

This patch fixes several corner cases in which the driver performs its part
of the flr flow out-of-order, causing the FW to assert due to badly timed
messages received from the driver.
Signed-off-by: NYuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: NAriel Elior <ariele@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      076d1329
    • O
      net: Add GRO support for vxlan traffic · dc01e7d3
      由 Or Gerlitz 提交于 
      Add GRO handlers for vxlann, by using the UDP GRO infrastructure.

For single TCP session that goes through vxlan tunneling I got nice
improvement from 6.8Gbs to 11.5Gbs

--> UDP/VXLAN GRO disabled
$ netperf  -H 192.168.52.147 -c -C

$ netperf -t TCP_STREAM -H 192.168.52.147 -c -C
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.52.147 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  65536  65536    10.00      6799.75   12.54    24.79    0.604   1.195

--> UDP/VXLAN GRO enabled

$ netperf -t TCP_STREAM -H 192.168.52.147 -c -C
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.52.147 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  65536  65536    10.00      11562.72   24.90    20.34    0.706   0.577
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dc01e7d3