1. 07 Apr, 2013 27 commits
  2. 06 Apr, 2013 1 commit
  3. 05 Apr, 2013 10 commits
  4. 04 Apr, 2013 1 commit
    • Jesper Dangaard Brouer's avatar
      net: frag queue per hash bucket locking · 19952cc4
      Jesper Dangaard Brouer authored
      This patch implements per hash bucket locking for the frag queue
      hash.  This removes two write locks, and the only remaining write
      lock is for protecting hash rebuild.  This essentially reduce the
      readers-writer lock to a rebuild lock.
      
      This patch is part of "net: frag performance followup"
       http://thread.gmane.org/gmane.linux.network/263644
      of which two patches have already been accepted:
      
      Same test setup as previous:
       (http://thread.gmane.org/gmane.linux.network/257155)
       Two 10G interfaces, on seperate NUMA nodes, are under-test, and uses
       Ethernet flow-control.  A third interface is used for generating the
       DoS attack (with trafgen).
      
      Notice, I have changed the frag DoS generator script to be more
      efficient/deadly.  Before it would only hit one RX queue, now its
      sending packets causing multi-queue RX, due to "better" RX hashing.
      
      Test types summary (netperf UDP_STREAM):
       Test-20G64K     == 2x10G with 65K fragments
       Test-20G3F      == 2x10G with 3x fragments (3*1472 bytes)
       Test-20G64K+DoS == Same as 20G64K with frag DoS
       Test-20G3F+DoS  == Same as 20G3F  with frag DoS
       Test-20G64K+MQ  == Same as 20G64K with Multi-Queue frag DoS
       Test-20G3F+MQ   == Same as 20G3F  with Multi-Queue frag DoS
      
      When I rebased this-patch(03) (on top of net-next commit a210576c) and
      removed the _bh spinlock, I saw a performance regression.  BUT this
      was caused by some unrelated change in-between.  See tests below.
      
      Test (A) is what I reported before for patch-02, accepted in commit 1b5ab0de.
      Test (B) verifying-retest of commit 1b5ab0de corrospond to patch-02.
      Test (C) is what I reported before for this-patch
      
      Test (D) is net-next master HEAD (commit a210576c), which reveals some
      (unknown) performance regression (compared against test (B)).
      Test (D) function as a new base-test.
      
      Performance table summary (in Mbit/s):
      
      (#) Test-type:  20G64K    20G3F    20G64K+DoS  20G3F+DoS  20G64K+MQ 20G3F+MQ
          ----------  -------   -------  ----------  ---------  --------  -------
      (A) Patch-02  : 18848.7   13230.1   4103.04     5310.36     130.0    440.2
      (B) 1b5ab0de  : 18841.5   13156.8   4101.08     5314.57     129.0    424.2
      (C) Patch-03v1: 18838.0   13490.5   4405.11     6814.72     196.6    461.6
      
      (D) a210576c  : 18321.5   11250.4   3635.34     5160.13     119.1    405.2
      (E) with _bh  : 17247.3   11492.6   3994.74     6405.29     166.7    413.6
      (F) without bh: 17471.3   11298.7   3818.05     6102.11     165.7    406.3
      
      Test (E) and (F) is this-patch(03), with(V1) and without(V2) the _bh spinlocks.
      
      I cannot explain the slow down for 20G64K (but its an artificial
      "lab-test" so I'm not worried).  But the other results does show
      improvements.  And test (E) "with _bh" version is slightly better.
      Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
      Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      
      ----
      V2:
      - By analysis from Hannes Frederic Sowa and Eric Dumazet, we don't
        need the spinlock _bh versions, as Netfilter currently does a
        local_bh_disable() before entering inet_fragment.
      - Fold-in desc from cover-mail
      V3:
      - Drop the chain_len counter per hash bucket.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      19952cc4
  5. 03 Apr, 2013 1 commit