[mythtv-users] [mythtv] mythcommflag taking all the cpu 0.19 svn revision 9806

Osma Ahvenlampi oa at iki.fi
Mon May 8 03:10:19 EDT 2006


On su, 2006-05-07 at 08:07 -0400, Khanh Tran wrote:
> On 5/6/06, Chris Pinkham <cpinkham at bc2va.org> wrote:
> > * On Sat May 06, 2006 at 10:38:28PM -0400, Khanh Tran wrote:
> > > Now I don't know what the problem is.  I removed those entries and I
> > > completely disabled mythcommflag jobs on the frontend/backend in
> > > question.  Xine still pauses, however not nearly as bad as when
> > > mythcommflag is running...
> > Are you sure you're using Xv output?  If you're having to do
> > video scaling in software and not hardware, that would slow down

> I'm not sure what's happening.  Xine has never been an issue for me
> until I went to the SVN head branch.  I'm not so sure it's
> mythcommflag now, due to my previous update.  What I am noticing now
> is that the whole box seems to freeze for a couple seconds every so
> often.

You never actually stated the machine's real state during this time that
I noticed. The loadav of 3.2 is mostly meaningless in this, as you're
running different kinds of loads simultaneously, and as such the problem
may be something totally different than cpu overload. Look at CPU
user/sys/nice/idle/wait and memory + swap allocation. My guess is that
you might be seeing mythcommflag hog memory and cause the machine to go
to swap - I regularly see this happening with both commflag and
transcode.

Try running 'vmstat 10' in a terminal in the backgroun. It'll show you
system state every ten seconds like this:

procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa st
 2  0      0 112076  68796 486592    0    0   222    78  381   771  9  2 84  4  0
 0  0      0 112076  68808 486596    0    0    16     0  342   494  1  0 98  1  0

           ^ little swap use    ^ should have memory left over for disk cache
                                     ^    ^  should not have swap activity
                                                ^     ^ should have disk i/o
 ^ the average of this column is 'loadav'                           ^     ^  ^ 
                                                  most cpu used should be us(er)
                                                          should have id(le) cpu
                         should not have a lot of wa(iting for io to finish) cpu

If I'm correct, you'll be seeing activity in the swap in/out and cpu
wait columns. A couple of percent of cpu wait is fine, but under a swap
storm you'd see anything up to high-80's.

-- 
Osma Ahvenlampi   <oa at iki.fi>    http://www.fishpool.org



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