lkml.org 
[lkml]   [2012]   [May]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints
    From
    Date
    On Thu, 2012-05-31 at 16:37 -0400, Steven Rostedt wrote:
    > On Thu, 2012-05-31 at 22:26 +0200, Peter Zijlstra wrote:
    >
    > > Right, but when you loose stop-machine you could simply do 30k
    > > kmap_atomic/kunmap_atomic's consecutively since you're not holding
    > > anybody up.
    >
    > It requires 3 IPIs per update too. Thus that's 90,000 IPIs you are
    > blasting^Wsending to all CPUs.
    >

    Note, currently ftrace adds breakpoints to all locations, sends out the
    IPIs, modifies the code, sends out the IPIs and then removes the
    breakpoint, sends out the IPIs.

    Just three IPIs for those 30,000 updates.

    -- Steve




    \
     
     \ /
      Last update: 2012-05-31 23:01    [W:0.025 / U:118.248 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site