Comment 11 for bug 1823753

Note that in current disco things have gotten worse - our single page allocations have blown up to 11753:

$ cat cma.disco.dmesg | grep "cma: cma_alloc(cma" | sed -r 's/.*count ([0-9]+)\,.*/\1/' | sort -n | uniq -c
  11753 1
      3 2
      3 4
    234 8
     32 16
      2 24
      4 32
    256 33
     39 64
      2 128
      2 1024

I bisected this down to a backport of the following commit:
3e394f9413ec RDMA/hns: Modify qp&cq&pd specification according to UM

Reverting that gets us down to 3029 single page allocations, freeing up about 34M.