On Mar 24, 2013, at 12:28 PM, Matthew Knepley <knepley at 
gmail.com<mailto:knepley at gmail.com>>
 wrote:

On Mon, Mar 25, 2013 at 12:42 AM, Blaise A Bourdin <bourdin at 
lsu.edu<mailto:bourdin at lsu.edu>> wrote:

On Mar 23, 2013, at 11:50 PM, Matthew Knepley <knepley at 
gmail.com<mailto:knepley at gmail.com>>
 wrote:

On Sun, Mar 24, 2013 at 12:24 PM, Blaise A Bourdin <bourdin at 
lsu.edu<mailto:bourdin at lsu.edu>> wrote:
Hi,

I am trying to do some scaling tests but can't figure out something about 
LogSummary: When no custom stages / events are defined, how come "Main Stage" 
is not 100% of the time? What is not counted? Here is a example of what I get:

Library loading?
Really? Is there anything I can do to test if it really is library loading or 
to reduce loading time? I am attaching the full log summary
Blaise


   Matt

Summary of Stages:   ----- Time ------  ----- Flops -----  --- Messages ---  -- 
Message Lengths --  -- Reductions --
                        Avg     %Total     Avg     %Total   counts   %Total     
Avg         %Total   counts   %Total
 0:      Main Stage: 2.5763e+03  65.1%  3.2380e+15 100.0%  1.230e+11 100.0%  
8.493e+02      100.0%  7.013e+06  97.0%

Where is the missing 35% of the time? I call PetscLogBegin right after 
PetscInitialize.

Okay, the total time is the time between PetscLogBegin() and the first several 
lines of PetscLogView(), before all the reductions.
Thus it does not look like library loading is responsible.

In this log, the main routine seems to be KSPSolve which takes 1.5e3. It looks 
like some time in this app is just not
being logged. That would take popping the current stage and then pushing it 
again afterwards I think. We would have
to know more about the code.

That's what bugs me... I removed all custom logging and custom events from the 
code. The code does not call any external library. Basically, it iterates 
assembling a matrix, calling KSPSolve, assembling another matrix, calling 
TAOSolve, and writing results in exodus format.

Is there a command line options that would give me some informations on the log 
level operations?

Blaise


--
Department of Mathematics and Center for Computation & Technology
Louisiana State University, Baton Rouge, LA 70803, USA
Tel. +1 (225) 578 1612, Fax  +1 (225) 578 4276 http://www.math.lsu.edu/~bourdin







-------------- next part --------------
An HTML attachment was scrubbed...
URL: 
<http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20130324/b2919be6/attachment.html>

Reply via email to