Hey Matt, All I want to be able to do is generate plots of |r|/|r0| vs cpu time. I presumed that such information is commonly required when profiling the performance of solvers, so I thought it might be something you'd consider adding support for. Cheers, Dave On Fri, May 9, 2008 at 1:19 PM, Matthew Knepley <[email protected]> wrote:

On Thu, May 8, 2008 at 10:09 PM, Dave May <[email protected]> wrote:

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Hey petsc folk, What is the best way to obtain timing information to profile the performance of KSPSolve (or SNESSolve)? Currently I have written some specific KSP monitors, but it I think it would be useful to have access to this information all the time without having to go through the monitor. It seems like each object should know how to time some of its operations.

It would be very useful to have functions such as KSPGetCPUTime(KSP ksp,PetscLogDouble *time) to report the total solution time required by the KSPSolve() and KSPGetCPUTimeHistory(KSP ksp,PetscLogDouble *time[],PetscInt *na) which is like KSPGetResidualHistory() but returns the accumulated cpu time for each iterate

It would also be useful to have a default KSP monitor which could report the time per iterate or accumulate time. For example something like 40 KSP Residual norm 1.519638506430e-01 Time 1.000000000000e-03 41 KSP Residual norm 1.510346481853e-01 Time 1.510346481853e-02

Is there a better approach to what I've been doing and are there plans to add any additional features to help profile individual operations on each object?

Maybe you could motivate it by giving a use case? So far, I have never needed anything but the KSPSolve() event and stages to separately aggregate different types of solves.

Matt

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Cheers, Dave -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener