When testing the newly-enabled Pylint analyzer in chromium/src, it took a full 10 minutes between uploading a new patchset and getting comments posted: See https://chromium-review.googlesource.com/c/chromium/src/+/1252845/2

First thing to check is where the latency is.

A few timing notes (all times PDT timezone):
 - patch upload at 2:48 PM
 - GitFileIsolator started at 2:51:27 PM
 - GitFileIsolator completed at 2:52:44 PM
 - Pylint started at 2:56:21 PM
 - Pylint completed at 2:56:29 PM
 - Comments posted at 2:58 PM

So it seems like it was slow to start both GitFileIsolator and Pylint; and it also took at least a minute to post after task completion

One little detail that seems important is this from the cloud tasks: the current rate is set to 1/s, for all task queues, whereas the actual rate of analyzers to run is probably more than 1/s:

  Queue Name	Tasks	Completed In Last Min.	Oldest Task ETA 	Maximum Rate
  driver-queue	141	60	2018-09-28 (15:10:28) 
(2 min 22 sec ago)	1/s