lkml.org 
[lkml]   [2017]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: possible circular locking dependency detected [was: linux-next: Tree for Aug 22]
    Hello Peter,

    On (08/30/17 10:47), Peter Zijlstra wrote:
    [..]
    > On Wed, Aug 30, 2017 at 10:42:07AM +0200, Peter Zijlstra wrote:
    > >
    > > So the overhead looks to be spread out over all sorts, which makes it
    > > harder to find and fix.
    > >
    > > stack unwinding is done lots and is fairly expensive, I've not yet
    > > checked if crossrelease does too much of that.
    >
    > Aah, we do an unconditional stack unwind for every __lock_acquire() now.
    > It keeps a trace in the xhlocks[].
    >
    > Does the below cure most of that overhead?

    thanks.

    mostly yes. the kernel is not so dramatically slower now. it's still
    seems to be a bit slower, which is expected I suppose, but over all
    it's much better

    real 1m35.209s
    user 4m12.467s
    sys 0m49.457s

    // approx 10 seconds slower.

    -ss

    \
     
     \ /
      Last update: 2017-08-30 14:27    [W:4.643 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site