diff --git a/RELEASE-NOTES-next b/RELEASE-NOTES-next
index 3b6de2711..77e290cf9 100644
--- a/RELEASE-NOTES-next
+++ b/RELEASE-NOTES-next
@@ -41,6 +41,7 @@ option is enabled and only then sets a screenshot as background.
   • Add %machine placeholder (WM_CLIENT_MACHINE) to title_format
   • Allow multiple output names in 'move container|workspace to output'
   • Add 'move container|workspace to output next'
+  • Add 'all' window matching criterion
 
  ┌────────────────────────────┐
  │ Bugfixes                   │
diff --git a/docs/userguide b/docs/userguide
index 3216ca1d9..cc5388af6 100644
--- a/docs/userguide
+++ b/docs/userguide
@@ -1976,12 +1976,17 @@ bindsym $mod+x [class="Firefox" window_role="About"] kill
 # enable floating mode and move container to workspace 4
 for_window [class="^evil-app$"] floating enable, move container to workspace 4
 
+# enable window icons for all windows with extra horizontal padding of 1px
+for_window [all] title_window_icon padding 1px
+
 # move all floating windows to the scratchpad
 bindsym $mod+x [floating] move scratchpad
 ------------------------------------
 
 The criteria which are currently implemented are:
 
+all::
+	Matches all windows. This criterion requires no value.
 class::
 	Compares the window class (the second part of WM_CLASS). Use the
 	special value +\_\_focused__+ to match all windows having the same window
diff --git a/include/data.h b/include/data.h
index 685d48d8f..ed0931cec 100644
--- a/include/data.h
+++ b/include/data.h
@@ -549,6 +549,7 @@ struct Match {
            WM_FLOATING_USER,
            WM_FLOATING } window_mode;
     Con *con_id;
+    bool match_all_windows;
 
     /* Where the window looking for a match should be inserted:
      *
diff --git a/libi3/get_process_filename.c b/libi3/get_process_filename.c
index 21429ec36..d29f8db1b 100644
--- a/libi3/get_process_filename.c
+++ b/libi3/get_process_filename.c
@@ -27,15 +27,14 @@ char *get_process_filename(const char *prefix) {
             char *tmp;
             sasprintf(&tmp, "%s/i3", dir);
             dir = tmp;
-            struct stat buf;
-            if (stat(dir, &buf) != 0) {
-                if (mkdir(dir, 0700) == -1) {
-                    warn("Could not mkdir(%s)", dir);
-                    errx(EXIT_FAILURE, "Check permissions of $XDG_RUNTIME_DIR = '%s'",
-                         getenv("XDG_RUNTIME_DIR"));
-                    perror("mkdir()");
-                    return NULL;
-                }
+            /* mkdirp() should prevent race between multiple i3 instances started
+             * in parallel from causing problem */
+            if (mkdirp(dir, 0700) == -1) {
+                warn("Could not mkdirp(%s)", dir);
+                errx(EXIT_FAILURE, "Check permissions of $XDG_RUNTIME_DIR = '%s'",
+                     getenv("XDG_RUNTIME_DIR"));
+                perror("mkdirp()");
+                return NULL;
             }
         } else {
             /* If not, we create a (secure) temp directory using the template
diff --git a/parser-specs/commands.spec b/parser-specs/commands.spec
index ff3a7cc7b..d53945d4c 100644
--- a/parser-specs/commands.spec
+++ b/parser-specs/commands.spec
@@ -57,7 +57,7 @@ state CRITERIA:
   ctype = 'urgent'      -> CRITERION
   ctype = 'workspace'   -> CRITERION
   ctype = 'machine'     -> CRITERION
-  ctype = 'tiling', 'floating'
+  ctype = 'tiling', 'floating', 'all'
       -> call cmd_criteria_add($ctype, NULL); CRITERIA
   ']' -> call cmd_criteria_match_windows(); INITIAL
 
diff --git a/parser-specs/config.spec b/parser-specs/config.spec
index cae21556a..2bd3434ef 100644
--- a/parser-specs/config.spec
+++ b/parser-specs/config.spec
@@ -227,7 +227,7 @@ state CRITERIA:
   ctype = 'machine'     -> CRITERION
   ctype = 'floating_from' -> CRITERION_FROM
   ctype = 'tiling_from'   -> CRITERION_FROM
-  ctype = 'tiling', 'floating'
+  ctype = 'tiling', 'floating', 'all'
       -> call cfg_criteria_add($ctype, NULL); CRITERIA
   ']'
       -> call cfg_criteria_pop_state()
diff --git a/src/match.c b/src/match.c
index 65646f9e5..34314e256 100644
--- a/src/match.c
+++ b/src/match.c
@@ -53,7 +53,8 @@ bool match_is_empty(Match *match) {
             match->window_type == UINT32_MAX &&
             match->con_id == NULL &&
             match->dock == M_NODOCK &&
-            match->window_mode == WM_ANY);
+            match->window_mode == WM_ANY &&
+            match->match_all_windows == false);
 }
 
 /*
@@ -260,6 +261,10 @@ bool match_matches_window(Match *match, i3Window *window) {
         LOG("window_mode matches\n");
     }
 
+    /* NOTE: See the comment regarding 'all' in match_parse_property()
+     * for an explanation of why match_all_windows isn't explicitly
+     * checked. */
+
     return true;
 }
 
@@ -438,5 +443,16 @@ void match_parse_property(Match *match, const char *ctype, const char *cvalue) {
         return;
     }
 
+    /* match_matches_window() only checks negatively, so match_all_windows
+     * won't actually be used there, but that's OK because if no negative
+     * match is found (e.g. because of a more restrictive criterion) the
+     * return value of match_matches_window() is true.
+     * Setting it here only serves to cause match_is_empty() to return false,
+     * otherwise empty criteria rules apply, and that's not what we want. */
+    if (strcmp(ctype, "all") == 0) {
+        match->match_all_windows = true;
+        return;
+    }
+
     ELOG("Unknown criterion: %s\n", ctype);
 }
diff --git a/testcases/t/315-all-criterion.t b/testcases/t/315-all-criterion.t
new file mode 100644
index 000000000..f11410fdb
--- /dev/null
+++ b/testcases/t/315-all-criterion.t
@@ -0,0 +1,90 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • https://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • https://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • https://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Tests all kinds of matching methods
+#
+use i3test;
+
+my $tmp = fresh_workspace;
+
+ok(@{get_ws_content($tmp)} == 0, 'no containers yet');
+
+# Open a new window
+my $window = open_window;
+my $content = get_ws_content($tmp);
+ok(@{$content} == 1, 'window mapped');
+my $win = $content->[0];
+
+######################################################################
+# check that simple matching works.
+######################################################################
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'window killed');
+
+######################################################################
+# check that simple matching against multiple windows works.
+######################################################################
+
+$tmp = fresh_workspace;
+
+my $left = open_window;
+ok($left->mapped, 'left window mapped');
+
+my $right = open_window;
+ok($right->mapped, 'right window mapped');
+
+# two windows should be here
+is_num_children($tmp, 2, 'two windows opened');
+
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'two windows killed');
+
+######################################################################
+# check that multiple criteria work are checked with a logical AND,
+# not a logical OR (that is, matching is not cancelled after the first
+# criterion matches).
+######################################################################
+
+$tmp = fresh_workspace;
+
+my $left = open_window(name => 'left');
+ok($left->mapped, 'left window mapped');
+
+my $right = open_window(name => 'right');
+ok($right->mapped, 'right window mapped');
+
+# two windows should be here
+is_num_children($tmp, 2, 'two windows opened');
+
+cmd '[all title="left"] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 1, 'one window still there');
+
+cmd '[all] kill';
+
+sync_with_i3;
+
+is_num_children($tmp, 0, 'all windows killed');
+
+done_testing;