"Too many open files" when running test.py about spatially-conditioned-graphs HOT 2 CLOSED

This appears to have nothing to do with the number of processes. As we reduce the number of processes to 1, the problem still occurs

from spatially-conditioned-graphs.

The problem is related to a few things

1. Limit on the number of file descriptors. Using larger limits can make the error disappear.
2. Number of classes (length of iterable) when using multiprocessing.pool. Smaller iterables appear to not cause the error.
3. Device type. Running the script on certain other devices do not cause the error, even with a smaller limit of file descriptors.

The very source of the error seems to be unclear still. But this will not be worked on anymore. At the moment there are two ways to avoid the error:

1. Run ulimit -n 4096 in bash to increase the limit on file descriptors. The default is 1024. Try the highest your device allows. This command, however, needs to be run every time a new bash shell is opened unless written in .bashrc
2. Change the parameter nproc of DetectionAPMeter to 1. This will disable the multiprocessing (fredzzhang/pocket@4cb92f3). The computation of mAP (even for 600 classes) is still fairly fast (10~20s) with a single process

from spatially-conditioned-graphs.