# PetscLogGpuTime
turn on the logging of GPU time for GPU kernels 
## Synopsis
```
#include "petscsys.h"   
PetscErrorCode PetscLogGpuTime(void)
```

## Options Database Key

- ***-log_view_gpu_time -*** provide the GPU times in the -log_view output





## Notes
Turning on the timing of the
GPU kernels can slow down the entire computation and should only be used when studying the performance
of operations on GPU such as vector operations and matrix-vector operations.

This routine should only be called once near the beginning of the program. Once it is started it cannot be turned off.


## See Also
 [](ch_profiling), `PetscLogView()`, `PetscLogGpuFlops()`, `PetscLogGpuTimeEnd()`, `PetscLogGpuTimeBegin()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/logging/plog.c.html#PetscLogGpuTime">src/sys/logging/plog.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/logging/plog.c)


[Index of all Profiling routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
