• Jesse Brandeburg's avatar
    i40e/i40evf: change dynamic interrupt thresholds · c56625d5
    Jesse Brandeburg authored
    The dynamic algorithm, while now working, doesn't have good
    performance in 40G mode.
    
    One part of this patch addresses the high CPU utilization of some small
    streaming workloads that the driver should reduce CPU in.
    
    It also changes the minimum ITR that the dynamic algorithm
    will settle on, causing our minimum latency to go from 12us
    to about 14us, when using adaptive mode.
    
    It also changes the BULK interrupt rate to allow maximum throughput
    on a 40Gb connection with a single thread of transmit, clamping
    interrupt rate to 8000 for TX makes single thread traffic go too
    slow.
    
    The new ULTRA bulk setting is introduced and is used
    when the Rx packet rate on this queue exceeds 40000 packets per
    second.  This value of 40000 was chosen because the automatic tuning
    of minimum ITR=20us means that a single queue can't quite achieve
    that many packets per second from a round-robin test.
    
    Change-ID: Icce8faa128688ca5fd2c4229bdd9726877a92ea2
    Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
    Tested-by: default avatarAndrew Bowers <andrewx.bowers@intel.com>
    Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
    c56625d5
i40e_txrx.h 10.7 KB