[petsc-users] Profile a matrix-free solver.

[Zou (Non-US), Ling]

Thank you very much!

Ling

On Fri, Jan 15, 2016 at 1:58 PM, Song Gao <song.gao2 at mail.mcgill.ca> wrote:

> Yes.
> http://www.sciencedirect.com/science/article/pii/S0021999198960764
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.sciencedirect.com_science_article_pii_S0021999198960764&d=BQMFaQ&c=54IZrppPQZKX9mLzcGdPfFD1hxrcB__aEkJFOKJFd00&r=kuHHom1yjd94zUrBWecnYg&m=Z6JmjYd7euHq--9l5maVEB6hJHAkMcMNyc8rnVhgDC8&s=wfmA2PxK68XsQhc1PzBC4HCsxtwNAhBAmxe5VvnLj8Q&e=>
>
> It's on page 668 equation 4.6.
>
> Thanks
>
> 2016-01-15 15:39 GMT-05:00 Zou (Non-US), Ling <ling.zou at inl.gov>:
>
>> Hi Song, I wonder if you have a reference paper on the preconditioning
>> algorithm you are working on, i.e., using the 1st order flux for
>> preconditioning purpose when your 'true' fluxes are evaluated using the 2nd
>> order AUSM scheme.
>>
>> Best,
>>
>> Ling
>>
>> On Fri, Jan 15, 2016 at 1:34 PM, Song Gao <song.gao2 at mail.mcgill.ca>
>> wrote:
>>
>>> Thanks. I'll try to improve "my code"
>>>
>>> 2016-01-15 14:56 GMT-05:00 Jed Brown <jed at jedbrown.org>:
>>>
>>>> Matthew Knepley <knepley at gmail.com> writes:
>>>> > The way I read this, you are taking about 23 iterates/solve, and most
>>>> of
>>>> > your work is residual computation which should
>>>> > be highly parallelizable/vectorizable. This seems great to me.
>>>>
>>>> This in the sense that it's up to you to determine whether your
>>>> matrix-free residual and preconditioning code is fast.  This profile
>>>> merely says that almost all of the run-time is in *your code*.  If your
>>>> code is fast, then this is good performance.  If you can use a different
>>>> algorithm to converge in fewer iterations, or a different representation
>>>> to apply the operator faster, then you could do better.
>>>>
>>>
>>>
>>
>
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