Nvidia cudamemcpy2d. (I just Feb 9, 2009 · I’ve noticed that some cudaMemcpy2D() calls take a significant amount of time to complete. cudaMemcpy2D ? As you know, you can call a device-side version of memcpy in a CUDA kernel simply by calling “memcpy”. I’ve managed to get gstreamer and OpenCV playing nice together, to a point. 2 (gt 230m with 6 SM, hence the 128*6). 1. You could follow these steps: Make the freeImageInteropNPP project links against nppicc. I have searched C/src/ directory for examples, but cannot fi&hellip; Widths and pitches are in bytes, not number of elements (the latter would not work because cudaMemcpy2D() does not know the element size). When I tried to do same with image size 640x480, its running perfectly. Does anyone see what I did wrong? Thanking you in anticipation #include <stdio. h> # include <cuda. 373 s batch: 54. Amazing. cudaMemcpy2D lets you copy a 3x3 submatrix of A, defined by rows 0 to 2 and columns 0 to 2 to the device into the space for B (the 3x3 Jun 8, 2012 · cudaMemcpy2D() expects the rows of the 2D matrix to be stored contiguously, and be passed a pointer to the start of the first row. The only value i get is pointer and i don’t understand why? This is an exemple of my code: double** busdata; double** lineda&hellip; Feb 1, 2012 · Yeah, I saw that, however, I am trying to get the following code but I am not able to get it working. Read a BGRA8 image with FreeImage(See original sample). 9. Instead the code passes a pointer to the array of row pointers. CUDA Runtime API Dec 7, 2009 · I tried a very simple CUDA program in order to learn the function API cudaMemcpy2D(); Here below is my src code, the result shows is not correct for the computing the matrix operation for A = B + C; #include <stdio. The really strange thing is that the routine works properly (does not hang) on GPU 1 (GTX 770, CC 3. Note: Note that this function may also return error codes from previous, asynchronous launches. x+threadIdx. y*blockDim. x*blockDim. h> // Kernel that executes on the CUDA device global void Aug 22, 2016 · I have a code like myKernel<<<…>>>(srcImg, dstImg) cudaMemcpy2D(…, cudaMemcpyDeviceToHost) where the CUDA kernel computes an image ‘dstImg’ (dstImg has its buffer in GPU memory) and the cudaMemcpy2D fn. The only value i get is pointer and i don’t understand why? This is an exemple of my code: double** busdata; double** lineda… Jul 9, 2009 · cudaMemcpy2D(d_mat2,pitch2,mat2,memWidth,memWidth,dim ,cudaMemcpyHostToDevice); checkCUDAError("Memcpy 2D"); d_mat2 is the matrix on the device here is the declaration cudaMallocPitch((void **)&d NVIDIA Developer Forums Jan 23, 2020 · Thank you very much. x * pitch) + threadIdx. y)=123; } main(){ int *p, p_h[5][5], i Feb 1, 2012 · There is a very brief mention of cudaMemcpy2D and it is not explained completely. g. You will need a separate memcpy operation for each pointer held in a1. com[/font] added. It's not trivial to handle a doubly-subscripted C array when copying data between host and device. There is no “deep” copy function for copying arrays of pointers and what they point to in the API. New replies are no longer allowed. Is there any other method to implement this in PVF 13. 572 MB/s memcpyDTH1 time: 1. In the previous three posts of this CUDA Fortran series we laid the groundwork for the major thrust of the series: how to optimize CUDA Fortran code. I think nobody actually uses the forum’s search… tera November 2, 2010, 12:28am Jul 9, 2008 · #include <stdio. Parameters: Returns: cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevicePointer, cudaErrorInvalidPitchValue, cudaErrorInvalidMemcpyDirection. I said “despite the naming”. It seems that cudaMemcpy2D refuses to copy data to a destination which has dpitch = width. At some point of iteration cudaMemcpy2D never returns back to the caller and thus caused the entire program to be stuck in the waiting state. I have searched C/src/ directory for examples, but cannot fi&hellip; Yes, cudaMallocPitch() is exactly meant to easily find the appropriate alignment and pitch for the current device to avoid uncoalesced accesses. I have searched C/src/ directory for examples, but cannot fi&hellip; Aug 3, 2015 · Hi, I’m currentyly trying to pass a 2d array to cuda with CudaMalloc pitch and CudaMemcpy2D. Jul 30, 2015 · So, if at all possible, use contiguous storage (possibly with row or column padding) for 2D matrices in both host and device code. I am not sure who popularized this storage organization, but I consider it harmful to any code that wants to deal with matrices efficiently Nov 1, 2010 · And if you wonder how to search the forum, use Google with [font=“Courier New”]site:forums. Nov 16, 2010 · #include <stdio. CUDA Toolkit v12. y Nov 29, 2012 · CUDA Fortran for Scientists and Engineers shows how high-performance application developers can leverage the power of GPUs using Fortran. 9? Thanks in advance. X) it hangs. cpp : Defines the entry point for the console application. I am merely saying that anybody who thinks “2D” in the name of this function implies collection-of-vectors storage is wide off the mark, and through no fault of the engineer who decided on the name of this API call (no, it wasn’t me :-) Maybe someone can pinpoint the (text)book that lead to a conflation of 2D Jul 30, 2015 · Since this is a pet peeve of mine: cudaMemcpy2D() is appropriately named in that it deals with 2D arrays. I found that in the books they use cudaMemCpy2D to implement this. x + threadIdx. Is is possible to call some of the more intelligent memcpy host functions on the device? Jul 18, 2011 · I am running an iterative tomographic application on a Tesla 1070-1U system. Since you say “1D array in a kernel” I am assuming that is not a pitched allocation on the device. h> __global__ void test(int *p, size_t pitch){ *((char *)p + threadIdx. 735 MB/s memcpyHTD2 time: 0. then copies the image ‘dstImg’ to an image ‘dstImgCpu’ (which has its buffer in CPU memory). For instance, say A is a 6x6 matrix on the host, and we allocated a 3x3 matrix B on the device previously. For two-dimensional array transfers, you can use cudaMemcpy2D(). cudaMemcpy2D(dest, dest_pitch, src, src_pitch, w, h, cudaMemcpyHostToDevice) Calling cudaMemcpy2D () with dst and src pointers that do not match the direction of the copy results in an undefined behavior. y) = 1; } # define X 30 # define Feb 1, 2012 · Hi, I was looking through the programming tutorial and best practices guide. dpitch. x * blockDim. I want to check if the copied data using cudaMemcpy2D() is actually there. What did i do wrong? [codebox]// example1. The simple fact is that many folks conflate a 2D array with a storage format that is doubly-subscripted, and also, in C, with something that is referenced via a double pointer. What I intended to do was to copy a host array of 760760 which would be inefficient to access to an array of 768768 which would be efficient for my device of compute capability 1. 0: cudaMemcpy2D (dst . cudaMemcpy2D is designed for copying from pitched, linear memory sources. 688 MB Bandwidth: 146. If for some reason you must use the collection-of-vectors storage scheme on the host, you will need to copy each individual vector with a separate cudaMemcpy* (). Jul 30, 2015 · I did not mean to imply that you consider cudaMemcpy2D inappropriately named. h> #include <stdlib. The host runs openSUSE 11. If the program would do it right, it should display 1 but it displays 2010. May 24, 2024 · Hi, I have two simple programs. 0 and copy back to host memory, but the code dies in cudaMemcpy2d. Can anyone tell me the reason behind this seemingly arbitrary limit? As far as I understood, having a pitch for a 2D array just means making sure the rows are the right size so that alignment is the same for every row and you still get coalesced memory access. I tried to use cudaMemcpy2D because it allows a copy with different pitch: in my case, destination has dpitch = width, but the source spitch > width. When i declare the 2d array statically my code works great. Windows 64-bit, Cuda Toolkit 5, newest drivers (march Mar 24, 2021 · Can someone kindly explain why GB/s for device to device cudaMemcpy shows an increasing trend? Conversely, doing a memcpy on CPU gives an expected behavior of step-wise decreasing GB/s as data size increases, initially giving higher GB/s as data can fit in cache and then decreasing as data gets bigger as it is fetched from off chip memory. This is a part of my code: [codebox]int **matrixH, *matrixD, **copy; size_&hellip; Jul 30, 2015 · Hi, I’m currentyly trying to pass a 2d array to cuda with CudaMalloc pitch and CudaMemcpy2D. Thanks #include &lt;stdio. The point is, I’m getting “invalid argument” errors from CUDA calls when attempting to do very basic stuff with the video frames. nvidia. Not the same thing. In the real code I move random numbers from the host to device. See also: Mar 20, 2011 · No it isn’t. The following are the trace from gdb where Aug 18, 2014 · Hello! I want to implement copy from device array to device array in the host code in CUDA Fortran by PVF 13. Here’s the output from a program with memcy2D() timed: memcpyHTD1 time: 0. Nightwish Aug 29, 2024 · Search In: Entire Site Just This Document clear search search. If the naming leads you to believe that cudaMemcpy2D is designed to handle a doubly-subscripted or a double-pointer referenceable Feb 1, 2012 · Widths and pitches are in bytes, not number of elements (the latter would not work because cudaMemcpy2D() does not know the element size). Here is the example code (running in my machine): #include <iostream> using Calling cudaMemcpy2D() with dst and src pointers that do not match the direction of the copy results in an undefined Generated by Doxygen for NVIDIA CUDA Library Jun 9, 2008 · I use the “cudaMemcpy2D” function as follow : cudaMemcpy2D(A, pA, B, pB, width_in_bytes, height, cudaMemcpyHostToDevice); As I know that B is an host float*, I have pB=width_in_bytes=N*sizeof(float). I’m using cudaMallocPitch() to allocate memory on device side. I’m not sure if I’m using cudaMallocPitch and cudaMemcpy2D correctly but I tried to use cudaMemcpy2D. h&gt; global void multi( double *M1, s&hellip; May 23, 2007 · I was wondering what are the max values for the cudaMemcpy() and the cudaMemcpy2D(); in terms of memory size cudaError_t cudaMemcpy2D(void* dst, size_t dpitch, const void* src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind); it’s not specified in the programming guide, I get a crash if I run this function with height bigger than 2^16 So I was w Jun 27, 2011 · I did some benchmarking on cudamemcpy2d and found that the times were more or less comparable with cudamemcpy. Thanks, Tushar Jul 7, 2009 · This is the code iam runing , i have used cudamemcpy2d to copy 2d array from Device to Host, and when I print it, It shows garbage, Can any body guide me . Thanks a ton. Thanks for your help anyway!! njuffa November 3, 2020, 9:50pm Nov 11, 2009 · direct to the question i need to copy 4 2d arrays to gpu, i use cudaMallocPitch and cudaMemcpy2D to accelerate its speed, but it turns out there are problems i can not figure out the code segment is as follows: int valid_dim[][NUM_USED_DIM]; int test_data_dim[][NUM_USED_DIM]; int *g_valid_dim; int *g_test_dim; //what i should say is the variable with a prefix g_ shows that it is on the gpu dst - Destination memory address : dpitch - Pitch of destination memory : src - Source memory address : spitch - Pitch of source memory : width - Width of matrix transfer (columns in bytes) Jul 29, 2009 · Update: With reference to above post, the program gives bizarre results when matrix size is increased say 10 * 9 etc . Here it is the code: [codebox]global void matrixCopy(float* a, float* c, int a_pitch, int c_pitch, int width) { int x = blockIdx. 876 s Jan 7, 2015 · Hi, I am new to Cuda Programming. Aug 20, 2007 · cudaMemcpy2D() fails with a pitch size greater than 2^18 = 262144. h> #define N 4 global static void MaxAdd(int *A, int *B, int *C, int pitch) { int xid = blockIdx. lib. The latter that is similar raises the following error at runtime. It was interesting to find that using cudamalloc and cudamemcpy vice cudamallocpitch and cudamemcpy2d for a matrix addition kernel I wrote was faster. Is there any way that i can transfer a dynamically declared 2d array with cudaMemcpy2D? Thank you in advance! Jun 20, 2012 · Greetings, I’m having some trouble to understand if I got something wrong in my programming or if there’s an unclear issue (to me) on copying 2D data between host and device. Two of four GPUs in this system are used for the computation, each running within a dedicated pthread. src. Since I am having some trouble, I developed a simple kernel, which copy a matrix into another. h> #define m 100 #define n 100 int main(){ int a[m][n]; int *b; int i,j; size_t pitch; for(i=0;i<m;i++){ for(j=0;j<n;j++){ a[i][j] = 1 cudaError_t cudaMemcpy2D (void * dst, size_t : dpitch, const void * src, size_t : spitch, size_t Generated by Doxygen for NVIDIA CUDA Library symbol - Symbol destination on device : src - Source memory address : count - Size in bytes to copy : offset - Offset from start of symbol in bytes : kind May 24, 2024 · This topic was automatically closed 14 days after the last reply. I have another question though, if you don’t mind. The memory areas may not overlap. x * pitch + threadIdx. h> #include <cutil. Apr 21, 2009 · Hello to All, I am trying to make some matrix computation, and I am using cudaMemcpy2D and cudaMallocPitch. [b]The problem I had is solved. This is an example. Feb 1, 2012 · I was looking through the programming tutorial and best practices guide. Oct 3, 2010 · Hi all I’m trying to copy a matrix on the GPU and to copy it back on the CPU: my target is learn how to use cudaMallocPitch and cudaMemcpy2D. But it is giving me segmentation fault. Mar 25, 2008 · I had a quick question about cudaMemcpy2D. __host__ float *d_ref; float **h_ref = new float* [width]; for (int i=0;i<width;i++) h_ref[i]= new float [height Sep 10, 2010 · Hello! I’m trying to make a 2d array, copy to cuda device increase every element by 1. 487 s batch: 109. Parameters: dst. As this uses much less storage than the 2D matrix expected, an out of bounds access occurs on the host side of the copy, leading to a segmentation fault. lib and nppisu. x; int yid Oct 30, 2020 · About the cudaMalloc3D and cudaMemcpy2D: I found out the memory could also be created with cudaMallocPitch, we used a depth of 1, so it is working with cudaMemcpy2D. There is a very brief mention of cudaMemcpy2D and it is not explained completely. Also copying to the device is about five times faster than copying back to the host. NVIDIA CUDA Library: cudaMemcpy. I am quite sure that I got all the parameters for the routine right. I can’t explain the behavior of device to device Jun 23, 2011 · Hi, This is my code, initializing a matrix d_ref and copying it to device. h” #include <stdio. x; int y = blockIdx. The former builds and runs without any issue. - Pitch of destination memory. Dec 1, 2016 · The principal purpose of cudaMemcpy2D and cudaMemcpy3D functions is to provide for the copying of data to or from pitched allocations. [/b] and is it the best way of doing this job? Thanks in advance. Jun 11, 2007 · Hi, I just had a large performance gain by padding arrays on the host in the same way as they are padded on the card and using cudaMemcpy instead of cudaMemcpy2D. cudaMemcpy2D () returns an error if dpitch or spitch exceeds the maximum allowed. - Destination memory address. 0), whereas on GPU 0 (GTX 960, CC 5. 6. h> global void test(int *p, size_t pitch){ *((int *)((char *)p + threadIdx. I also got very few references to it on this forum. It took me some time to figure out that cudaMemcpy2D is very slow and that this is the performance problem I have. 375 MB Bandwidth: 224. A little warning in the programming guide concerning this would be nice ;-) Jun 1, 2022 · Hi ! I am trying to copy a device buffer into another device buffer. Do I have to insert a ‘cudaDeviceSynchronize’ before the ‘cudaMemcpy2D’ in Mar 20, 2011 · No it isn’t. What I think is happening is: the gstreamer video decoder pipeline is set to leave frame data in NVMM memory Aug 17, 2014 · Hello! I want to implement copy from device array to device array in the host code in CUDA Fortran by PVF 13. I think the problem is in the CudaMemcpy2D. h> #include <cuda. Aug 20, 2019 · The sample does this cuvidMapVideoFrame Create destination frames using cuMemAlloc (Driver API) cuMemcpy2DAsync (Driver API) (copy mapped frame to allocated frame) Can this instead be done: cuvidMapVideoFrame Create destination frames using cudaMalloc (Runtime API) cudaMemcpy2DAsync (Runtime API) (copy mapped frame to allocated frame) dst - Destination memory address : wOffset - Destination starting X offset : hOffset - Destination starting Y offset : src - Source memory address : spitch Mar 31, 2015 · I have a strange problem: my ‘cudaMemcpy2D’ functions hangs (never finishes), when doing a copy from host to device. Could you please take a look at it? I would be glad to finally understand Feb 1, 2012 · There is a very brief mention of cudaMemcpy2D and it is not explained completely. The issue is with host code that tries to pass off a collection of non-contiguous row vectors (or column vectors) as a 2D array. How to use this API to implement this. h> #include <cuda_runtime. Dec 20, 2011 · Thank you for the reply. If you are making a CP from host to device then what do you use for the source pitch since it was not allocated with cudaMallocPitch? Apr 4, 2020 · e. Can anyone please tell me reason for that. There is no obvious reason why there should be a size limit. But I found a workout where I prepare data as 1D array , then use cudamaalocPitch() to place the data in 2D format, do processing and then retrieve data back as 1D array. I am trying to allocate memory for image size 1366x768 using CudaMallocPitch and transferring data to Device using cudaMemcpy2D/ cudaMalloc . Calling cudaMemcpy2D() with dst and src pointers that do not match the direction of the copy results in an undefined Generated by Doxygen for NVIDIA CUDA Library Jan 12, 2022 · I’ve come across a puzzling issue with processing videos from OpenCV. dst - Destination memory address : src - Source memory address : count - Size in bytes to copy : kind - Type of transfer : stream - Stream identifier Sep 4, 2011 · The first and second arguments need to be swapped in the following calls: cudaMemcpy(gpu_found_index, cpu_found_index, foundSize, cudaMemcpyDeviceToHost); cudaMemcpy(gpu_memory_block, cpu_memory_block, memSize, cudaMemcpyDeviceToHost); Jul 30, 2015 · I didn’t say cudaMemcpy2D is inappropriately named. I cannot believe that I was making such a mistake. I have searched C/src/ directory for examples, but cannot find any. Mar 27, 2019 · In CUDA, there is cudaMemcpy2D, which lets you copy a 2D sub-matrix of a larger matrix on the host to a smaller matrix on the device (or vice versa). - Source memory address. But when i declare it dynamically, as a double pointer, my array is not correctly transfered. For the most part, cudaMemcpy (including cudaMemcpy2D) expect an ordinary pointer for source and destination, not a pointer-to-pointer. Oct 20, 2010 · Hi, I wanted to copy a 2D array from the CPU to the GPU and than back to the CPU. // //#include “stdafx. I am new to using cuda, can someone explain why this is not possible? Using width-1 Nov 8, 2017 · Hello, i am trying to transfer a 2d array from cpu to gpu with cudaMemcpy2D. Copies count bytes from the memory area pointed to by src to the memory area pointed to by dst, where kind is one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, or cudaMemcpyDeviceToDevice, and specifies the direction of the copy. dwfnimd amkpzub ixot iam waa isyd vssab jxu lavknu ubd