• Ying Xue's avatar
    tipc: change socket buffer overflow control to respect sk_rcvbuf · cc79dd1b
    Ying Xue authored
    As per feedback from the netdev community, we change the buffer
    overflow protection algorithm in receiving sockets so that it
    always respects the nominal upper limit set in sk_rcvbuf.
    
    Instead of scaling up from a small sk_rcvbuf value, which leads to
    violation of the configured sk_rcvbuf limit, we now calculate the
    weighted per-message limit by scaling down from a much bigger value,
    still in the same field, according to the importance priority of the
    received message.
    
    To allow for administrative tunability of the socket receive buffer
    size, we create a tipc_rmem sysctl variable to allow the user to
    configure an even bigger value via sysctl command.  It is a size of
    three (min/default/max) to be consistent with things like tcp_rmem.
    
    By default, the value initialized in tipc_rmem[1] is equal to the
    receive socket size needed by a TIPC_CRITICAL_IMPORTANCE message.
    This value is also set as the default value of sk_rcvbuf.
    Originally-by: default avatarJon Maloy <jon.maloy@ericsson.com>
    Cc: Neil Horman <nhorman@tuxdriver.com>
    Cc: Jon Maloy <jon.maloy@ericsson.com>
    [Ying: added sysctl variation to Jon's original patch]
    Signed-off-by: default avatarYing Xue <ying.xue@windriver.com>
    [PG: don't compile sysctl.c if not config'd; add Documentation]
    Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    cc79dd1b
core.h 6.14 KB