[petsc-users] [petsc-maint #107932] run a simple example ex19 in src/snes/examples/tutorials

[Matthew Knepley]

2012/3/5 Xiangze Zeng <zengshixiangze at 163.com>

> Hi, Matt.
>
> We know that when we compile the CUDA-C code, we use nvcc. But if we run
> the PETSc-CUDA code in GPU, what we do is just to change the type of Mat
> and Vec. In the PETSc-CUDA code compilings progress ,does it use nvcc?
>

Yes.


> And when implement the PETSc for using GPU, do you ever consider the
> comupute capibility of the GPU. And in which place, the parameter of the
> comupute capibility of the GPU has been set?
>

You configure using --with-cuda-arch=sm_13 for instance, or compute_12.

And you have given me an idea what your problem is. The GeForce 310 has no
double precision floating point units.
Therefore, you must configure PETSc using --with-precision=single.

    Matt


> Thank you.
> Zeng
>
> 在 2012-03-05 22:28:20，"Matthew Knepley" <petsc-maint at mcs.anl.gov> 写道：
>
> On Mon, Mar 5, 2012 at 8:18 AM, Xiangze Zeng <zengshixiangze at 163.com>wrote:
>
>> Hi, Matt.
>> I have tried the method you told me( I closed all the X systems),but the
>> same error still occurs. Is there something wrong with the installation of
>> the  thrust?
>>
>>
>> And I find the same problem in several web pages, like this
>> http://code.google.com/p/thrust/wiki/Debugging, they all say the error
>> is related to the compute capability . Is that the case?  My GPU is GeForce
>> 310, which supports compute capability 1.2 .
>>
>
> One of the downsides of CUDA, at least from our perspective, is that these
> errors are very
> hard to debug. If thrust compiles and the cudaInit() succeeds, there is
> not much else we
> can do to debug on this machine. Maybe you can try running thrust examples?
>
>    Matt
>
>
>> Thank you.
>>
>> 在 2012-03-02 23:55:13，"Matthew Knepley" <petsc-maint at mcs.anl.gov> 写道：
>> On Fri, Mar 2, 2012 at 9:40 AM, Xiangze Zeng <zengshixiangze at 163.com>
>> wrote:
>>
>> Thank both of you, Satish and Jed.
>>
>>
>> This warning message has disappeared. But another problem occurs, it
>> terminates with the same message as I run my own code:"
>> terminate called after throwing an instance of
>> 'thrust::system::system_error'
>> what():  invalid device function
>> Aborted."
>> (Several days ago, I thought I run the ex19 successfully, but today I
>> found I was totally wrong when I find the warning message in the PETSc
>> Performance Summary. So sorry about that!)
>>
>>
>>
>> Most likely, this a problem with another program locking your GPU (I
>> assume you are running on your laptop/desktop). Start
>> closing apps one at a time (especially graphical ones like a PDF reader)
>> and try running each time.
>>
>>
>>   Matt
>>
>> May this new problem be related to the installation of the cuda( I can
>> run cuda-C code successfully in my PC)?
>>
>>
>> Thank you again!
>> Zeng Xiangze
>>
>> At 2012-03-02 23:18:19,"Satish Balay" <petsc-maint at mcs.anl.gov> wrote:
>> >On Fri, 2 Mar 2012, Xiangze Zeng wrote:
>> >
>>
>> >> Dear all,
>> >>
>> >> After I have installed the PETSc to use the NVidia GPUS, I run the
>> ex19. When I make ex19, it stopped with the message:
>> >>
>> >>
>> >> "makefile:24: /conf/variables: No such file or directory
>> >> makefile:25: /conf/rules: No such file or directory
>> >> makefile:1023: /conf/test: No such file or directory
>> >> make: *** No rule to make target `/conf/test'.  Stop."
>> >>
>> >>
>> >> Then I add the PETSC_DIR to the makefile. After that, I made ex19
>> successfully. But when I run it using the command :
>> >
>>
>> >Yes - you need PETSC_DIR/PETSC_ARCH values to be specified to
>> >make. You can set these as env variables - or specify to make on the
>> >command line - or add to makefile. [we recommended not modifying the
>> >makefile - to keep it portable..]
>> >
>> >>
>> >>
>>
>> >> "./ex19 -da_vec_type mpicusp -da_mat_type mpiaijcusp -pc_type none
>> -dmmg_nlevels 1 -da_grid_x 100 -da_grid_y 100 -log_summary -mat_no_inode
>> -preload off  -cusp_synchronize".
>> >>
>> >>
>> >> In the  PETSc Performance Summary, it says:"
>> >> WARNING! There are options you set that were not used!
>> >> WARNING! could be spelling mistake, etc!
>> >> Option left: name:-da_mat_type value: mpiaijcusp
>> >> Option left: name:-da_vec_type value: mpicusp"
>> >
>>
>> >Looks like the options are now changed to -dm_mat_type and -dm_vec_type.
>> >
>> >Satish
>> >
>> >>
>> >>
>>
>> >> Is there any problem with it?
>> >> Any response will be appreciated! Thank you so much!
>> >>
>> >>
>> >> Zeng Xiangze
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >
>>
>>
>>
>>
>>
>>
>>
>> --
>> 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
>>
>>
>
>
> --
> 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
>
>
>
>


-- 
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
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