• Eric Dumazet's avatar
    net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls · 3ab5aee7
    Eric Dumazet authored
    RCU was added to UDP lookups, using a fast infrastructure :
    - sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the
      price of call_rcu() at freeing time.
    - hlist_nulls permits to use few memory barriers.
    This patch uses same infrastructure for TCP/DCCP established
    and timewait sockets.
    Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications
    using short lived TCP connections. A followup patch, converting
    rwlocks to spinlocks will even speedup this case.
    __inet_lookup_established() is pretty fast now we dont have to
    dirty a contended cache line (read_lock/read_unlock)
    Only established and timewait hashtable are converted to RCU
    (bind table and listen table are still using traditional locking)
    Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
inet_hashtables.c 14.5 KB