automatalab / subway Goto Github PK

Hi,

Throughout your entire code, you use uint to represent your pointers to the edges.
I was attempting to preprocess an RMAT dataset similar to how you have in the paper and the preprocessing causes the graph to have a mere 5GB of memory.

After running with a simple graph，a segmentation fault occurred
check the graph.cu I found that in line 156

                        uint *outDegreeCounter  = new uint[num_nodes];
			uint location;  
			for(uint i=0; i<num_edges; i++)
			{
				location = nodePointer[edges[i].source] + outDegreeCounter[edges[i].source];
				edgeList[location].end = edges[i].end;
				//if(isWeighted)
				//	edgeList[location].w8 = edges[i].w8;
				outDegreeCounter[edges[i].source]++;  
			}

The outDegreeCounter array should be initialized

After make, run the instruction. / bfs-sync -- input. / edge_ 875713.el

The tips are as follows:
Reading the input graph from the following file:

    ./edge_875713.el
    Done reading.
    Number of nodes = 875713
    Number of edges = 9238952
    Graph Reading finished in 1.80066 (s).
    GPUassert: out of memory subgraph.cu 40

Why is it out of memory

On line 75 in subgraph_generator.cu, ceil() is useless with integer division.
Should be unsigned int chunkSize = (unsigned int)ceil((double)numActiveNodes / numThreads);

Results in not copying some data to the edge array, sending the old values to the kernel which results in undefined behavior; usually erroneous values in the last .01% of the nodes (but can propagate through the rest of the graph).

I tried SNAP web-graph dataset http://snap.stanford.edu/data/web-Google.html and found that the result was incorrect.

Ground-truth: The nodes in largest weak connected component: 855,802

./cc-sync --input webgraph_reindex_space.el --output result.txt

Then I calculated the largest WCC which contains 600,493 nodes (incorrect).

Dear author of Subway,
Hi, I am reading your article these days and want to see the source code to deepen understanding. In your readme, you promised the source code will be posted around mid-May, but May is coming to an end. I would appreciate it if you can reply me in this issue. Thanks!

Where is the PageRank