diff --git a/ietf/mailinglists/management/commands/import_mailman_listinfo.py b/ietf/mailinglists/management/commands/import_mailman_listinfo.py
index 67e93ed51..6c0010373 100644
--- a/ietf/mailinglists/management/commands/import_mailman_listinfo.py
+++ b/ietf/mailinglists/management/commands/import_mailman_listinfo.py
@@ -1,6 +1,7 @@
 # Copyright The IETF Trust 2016-2019, All Rights Reserved
 
 import sys
+import time
 from textwrap import dedent
 
 import debug                            # pyflakes:ignore
@@ -21,24 +22,40 @@ except ImportError:
     pass
 
 from ietf.mailinglists.models import List, Subscribed
+from ietf.utils.log import log
 from ietf.utils.text import decode
 
+mark = time.time()
+
 def import_mailman_listinfo(verbosity=0):
     def note(msg):
-        if verbosity > 1:
+        if verbosity > 2:
             sys.stdout.write(msg)
             sys.stdout.write('\n')
+    def log_time(msg):
+        global mark
+        if verbosity > 1:
+            t = time.time()
+            log(msg+' (%.1fs)'% (t-mark))
+            mark = t
 
     if not have_mailman:
         note("Could not import mailman modules -- skipping import of mailman list info")
         return
 
+    log("Starting import of list info from Mailman")
     names = list(Utils.list_names())
     names.sort()
+    log_time("Fetched list of mailman list names")
     addr_max_length = Subscribed._meta.get_field('email').max_length
+    
+    subscribed = { l.name: set(l.subscribed_set.values_list('email', flat=True)) for l in List.objects.all().prefetch_related('subscribed_set') }
+    log_time("Computed dictionary of list members")
+
     for name in names:
         mlist = MailList.MailList(name, lock=False)
         note("List: %s" % mlist.internal_name())
+        log_time("Fetched Mailman list object for %s" % name)
 
         lists = List.objects.filter(name=mlist.real_name)
         if lists.count() > 1:
@@ -46,35 +63,58 @@ def import_mailman_listinfo(verbosity=0):
             for item in lists[1:]:
                 item.delete()
         mmlist, created = List.objects.get_or_create(name=mlist.real_name)
-        mmlist.description = decode(mlist.description)[:256]
-        mmlist.advertised = mlist.advertised
-        mmlist.save()
+        dirty = False
+        desc = decode(mlist.description)[:256]
+        if mmlist.description != desc:
+            mmlist.description = desc
+            dirtry = True
+        if mmlist.advertised != mlist.advertised:
+            mmlist.advertised = mlist.advertised
+            dirty = True
+        if dirty:
+            mmlist.save()
+        log_time("  Updated database List object for %s" % name)
         # The following calls return lowercased addresses
         if mlist.advertised:
             members = mlist.getRegularMemberKeys() + mlist.getDigestMemberKeys()
-            members = [ m for m in members if mlist.getDeliveryStatus(m) == MemberAdaptor.ENABLED ]
-            known = Subscribed.objects.filter(lists__name=name).values_list('email', flat=True)
-            for addr in known:
-                if not addr in members:
+            log_time("  Fetched list of list members")
+            members = set([ m for m in members if mlist.getDeliveryStatus(m) == MemberAdaptor.ENABLED ])
+            log_time("  Filtered list of list members")
+            if not mlist.real_name in subscribed:
+                log("Note: didn't find '%s' in the dictionary of subscriptions" % mlist.real_name)
+                continue
+            known = subscribed[mlist.real_name]
+            log_time("  Fetched known list members from database")            
+            to_remove = known - members
+            to_add = members - known
+            for addr in to_remove:
                     note("  Removing subscription: %s" % (addr))
                     old = Subscribed.objects.get(email=addr)
+                    log_time("    Fetched subscribed object")
                     old.lists.remove(mmlist)
+                    log_time("    Removed %s from %s" % (mmlist, old))
                     if old.lists.count() == 0:
                         note("    Removing address with no subscriptions: %s" % (addr))
                         old.delete()
-            for addr in members:
+                        log_time("      Removed %s" % old)
+            log_time("  Removed addresses no longer subscribed")
+            if to_remove:
+                log("  Removed %s addresses from %s" % (len(to_remove), name))
+            for addr in to_add:
                 if len(addr) > addr_max_length:
                     sys.stderr.write("    **  Email address subscribed to '%s' too long for table: <%s>\n" % (name, addr))
                     continue
-                if not addr in known:
-                    note("  Adding subscription: %s" % (addr))
-                    try:
-                        new, created = Subscribed.objects.get_or_create(email=addr)
-                    except MultipleObjectsReturned as e:
-                        sys.stderr.write("    **  Error handling %s in %s: %s\n" % (addr, name, e))
-                        continue
-                    new.lists.add(mmlist)
-    
+                note("  Adding subscription: %s" % (addr))
+                try:
+                    new, created = Subscribed.objects.get_or_create(email=addr)
+                except MultipleObjectsReturned as e:
+                    sys.stderr.write("    **  Error handling %s in %s: %s\n" % (addr, name, e))
+                    continue
+                new.lists.add(mmlist)
+            log_time("  Added new addresses")
+            if to_add:
+                log("  Added %s addresses to %s" % (len(to_add), name))
+    log("Completed import of list info from Mailman")    
 
 class Command(BaseCommand):
     """