lkml.org 
[lkml]   [2009]   [Jun]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [KVM-RFC PATCH 1/2] eventfd: add an explicit srcu based notifier interface
    On Thu, 18 Jun 2009, Michael S. Tsirkin wrote:

    > On Wed, Jun 17, 2009 at 04:21:19PM -0700, Davide Libenzi wrote:
    > > The interface is just ugly IMO. You have eventfd_signal() that can sleep,
    > > or not, depending on the registered ->signal() function implementations.
    > > This is pretty bad, a lot worse than the theoretical us spent in the
    > > schedule_work() processing.
    >
    > I agree. How about the idea of introducing eventfd_signal_from_task
    > which can sleep? Does this sound same?

    You're basically asking to double the size of eventfd, make the signal
    path heavier, make the eventf size bigger, w/out having provided any *real
    life* measurement whatsoever to build a case for it.
    WAY too much stuff went in by just branding the latest coolest names as
    reasons for them.
    And all this to remove the wakeup of a *kernel* thread going to run in the
    same CPU where the work has been scheduled.
    Come back with *replicable* real life benchmarks, and then we'll see what
    the best approach to address it will be.



    - Davide




    \
     
     \ /
      Last update: 2009-06-18 20:01    [W:4.228 / U:0.840 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site