DMA questions

I’m working on optimizing my project, which uses DMA, and have a few questions about best practices on the software side of things as I’m more of an RTL person.

My design is a search engine that compares data provided to the FPGA from the computer against a reference library stored in the DDR. I load GBs of data to the DDR in a single dump on startup but then need to make ~100 4kB writes per second to keep the library updated. The data in each update is written to consecutive DDR addresses but the updates are scattered throughout the DDR address space. My drivers use fpga_dma.h.

Questions:

1. Is it better practice to open a DMA queue a single time and store the descriptor in my driver library, which would potentially leave the queue open for days, or should I open and close the DMA queue every time I do a write?

2. I’d like to have the XDMA driver load automatically when the F1 instance is powered up but it’s not doing that after I follow the instructions in the link below. Is it supposed to be persistent? I’m using the FPGA Dev AMI v1.9.1 but am having to follow the full instructions each time so DMA works, maybe because of the XOCL driver conflict as it seems to be coming back each reboot. Very possible I've screwed up something as my unix skills are google/cut/paste.

https://github.com/aws/aws-fpga/blob/master/sdk/linux_kernel_drivers/xdma/xdma_install.md#xdmainstallfail