diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -444,7 +444,7 @@ coreconfigitem('experimental', 'sparse-r
 coreconfigitem('experimental', 'sparse-read.density-threshold',
     default=0.25,
 )
-coreconfigitem('experimental', 'sparse-read.min-block-size',
+coreconfigitem('experimental', 'sparse-read.min-gap-size',
     default='256K',
 )
 coreconfigitem('experimental', 'treemanifest',
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -611,11 +611,11 @@ class localrepository(object):
         withsparseread = self.ui.configbool('experimental', 'sparse-read')
         srdensitythres = float(self.ui.config('experimental',
                                               'sparse-read.density-threshold'))
-        srminblocksize = self.ui.configbytes('experimental',
-                                             'sparse-read.min-block-size')
+        srmingapsize = self.ui.configbytes('experimental',
+                                           'sparse-read.min-gap-size')
         self.svfs.options['with-sparse-read'] = withsparseread
         self.svfs.options['sparse-read-density-threshold'] = srdensitythres
-        self.svfs.options['sparse-read-min-block-size'] = srminblocksize
+        self.svfs.options['sparse-read-min-gap-size'] = srmingapsize
 
         for r in self.requirements:
             if r.startswith('exp-compression-'):
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -196,7 +196,8 @@ def _slicechunk(revlog, revs):
 
         if prevend is not None:
             gapsize = revstart - prevend
-            if gapsize:
+            # only consider holes that are large enough
+            if gapsize > revlog._srmingapsize:
                 heapq.heappush(gapsheap, (-gapsize, i))
 
         prevend = revstart + revlen
@@ -371,7 +372,7 @@ class revlog(object):
         self._maxdeltachainspan = -1
         self._withsparseread = False
         self._srdensitythreshold = 0.25
-        self._srminblocksize = 262144
+        self._srmingapsize = 262144
 
         mmapindexthreshold = None
         v = REVLOG_DEFAULT_VERSION
@@ -401,8 +402,8 @@ class revlog(object):
             self._withsparseread = bool(opts.get('with-sparse-read', False))
             if 'sparse-read-density-threshold' in opts:
                 self._srdensitythreshold = opts['sparse-read-density-threshold']
-            if 'sparse-read-min-block-size' in opts:
-                self._srminblocksize = opts['sparse-read-min-block-size']
+            if 'sparse-read-min-gap-size' in opts:
+                self._srmingapsize = opts['sparse-read-min-gap-size']
 
         if self._chunkcachesize <= 0:
             raise RevlogError(_('revlog chunk cache size %r is not greater '