lkml.org 
[lkml]   [2013]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
    From
    Date
    On Wed, 2013-05-29 at 17:14 +0300, Or Gerlitz wrote:
    > On Wed, May 29, 2013 at 9:39 AM, Eliezer Tamir
    > <eliezer.tamir@linux.intel.com> wrote:
    > > Adds a new ndo_ll_poll method and the code that supports and uses it.
    > > This method can be used by low latency applications to busy poll Ethernet
    > > device queues directly from the socket code. The value of sysctl_net_ll_poll
    > > controls how many microseconds to poll. Set to zero to disable.
    >
    > Unlike with TCP sockets, UDP sockets may receive packets from multiple
    > sources and hence the receiving context may be steered to be executed
    > on different cores through RSS or other Flow-Steering HW mechanisms
    > which could mean different napi contexts for the same socket, is that
    > a problem here? what's the severity?

    Maybe ARFS could be extended so the driver can tell whether a UDP socket
    it's steering for is connected or not. Then for disconnected sockets
    the driver can use a filter that only matches destination address.
    (Though that's probably undesirable if the socket has SO_REUSEPORT set.)

    Ben.

    --
    Ben Hutchings, Staff Engineer, Solarflare
    Not speaking for my employer; that's the marketing department's job.
    They asked us to note that Solarflare product names are trademarked.



    \
     
     \ /
      Last update: 2013-05-29 22:41    [W:2.104 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site