• Fan Du's avatar
    ipv4: Use binary search to choose tcp PMTU probe_size · 6b58e0a5
    Fan Du authored
    Current probe_size is chosen by doubling mss_cache,
    the probing process will end shortly with a sub-optimal
    mss size, and the link mtu will not be taken full
    advantage of, in return, this will make user to tweak
    tcp_base_mss with care.
    
    Use binary search to choose probe_size in a fine
    granularity manner, an optimal mss will be found
    to boost performance as its maxmium.
    
    In addition, introduce a sysctl_tcp_probe_threshold
    to control when probing will stop in respect to
    the width of search range.
    
    Test env:
    Docker instance with vxlan encapuslation(82599EB)
    iperf -c 10.0.0.24  -t 60
    
    before this patch:
    1.26 Gbits/sec
    
    After this patch: increase 26%
    1.59 Gbits/sec
    Signed-off-by: default avatarFan Du <fan.du@intel.com>
    Acked-by: default avatarJohn Heffner <johnwheffner@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6b58e0a5
ipv4.h 2.42 KB