From 7c6c99b8295829580c506067495a23c07436e266 Mon Sep 17 00:00:00 2001
From: Dave Watson <davejwatson@fb.com>
Date: Tue, 26 Sep 2017 17:22:01 -0700
Subject: [PATCH] Use ph instead of rb tree for extents_avail_

There does not seem to be any overlap between usage of
extent_avail and extent_heap, so we can use the same hook.

The only remaining usage of rb trees is in the profiling code,
which has some 'interesting' iteration constraints.

Fixes #888
---
 include/jemalloc/internal/extent_externs.h |  1 -
 include/jemalloc/internal/extent_structs.h | 28 ++++++++++------------
 src/extent.c                               |  2 +-
 3 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/include/jemalloc/internal/extent_externs.h b/include/jemalloc/internal/extent_externs.h
index 489a813c..9da5d010 100644
--- a/include/jemalloc/internal/extent_externs.h
+++ b/include/jemalloc/internal/extent_externs.h
@@ -4,7 +4,6 @@
 #include "jemalloc/internal/mutex.h"
 #include "jemalloc/internal/mutex_pool.h"
 #include "jemalloc/internal/ph.h"
-#include "jemalloc/internal/rb.h"
 #include "jemalloc/internal/rtree.h"
 
 extern rtree_t			extents_rtree;
diff --git a/include/jemalloc/internal/extent_structs.h b/include/jemalloc/internal/extent_structs.h
index d2979503..641a6325 100644
--- a/include/jemalloc/internal/extent_structs.h
+++ b/include/jemalloc/internal/extent_structs.h
@@ -5,7 +5,6 @@
 #include "jemalloc/internal/bitmap.h"
 #include "jemalloc/internal/mutex.h"
 #include "jemalloc/internal/ql.h"
-#include "jemalloc/internal/rb.h"
 #include "jemalloc/internal/ph.h"
 #include "jemalloc/internal/size_classes.h"
 
@@ -120,20 +119,19 @@ struct extent_s {
 		size_t			e_bsize;
 	};
 
-	union {
-		/*
-		 * List linkage, used by a variety of lists:
-		 * - arena_bin_t's slabs_full
-		 * - extents_t's LRU
-		 * - stashed dirty extents
-		 * - arena's large allocations
-		 */
-		ql_elm(extent_t)	ql_link;
-		/* Red-black tree linkage, used by arena's extent_avail. */
-		rb_node(extent_t)	rb_link;
-	};
+	/*
+	 * List linkage, used by a variety of lists:
+	 * - arena_bin_t's slabs_full
+	 * - extents_t's LRU
+	 * - stashed dirty extents
+	 * - arena's large allocations
+	 */
+	ql_elm(extent_t)	ql_link;
 
-	/* Linkage for per size class sn/address-ordered heaps. */
+	/* 
+	 * Linkage for per size class sn/address-ordered heaps, and
+	 * for extent_avail
+	 */
 	phn(extent_t)		ph_link;
 
 	union {
@@ -148,7 +146,7 @@ struct extent_s {
 	};
 };
 typedef ql_head(extent_t) extent_list_t;
-typedef rb_tree(extent_t) extent_tree_t;
+typedef ph(extent_t) extent_tree_t;
 typedef ph(extent_t) extent_heap_t;
 
 /* Quantized collection of extents, with built-in LRU queue. */
diff --git a/src/extent.c b/src/extent.c
index 3f1c76fd..221c80c0 100644
--- a/src/extent.c
+++ b/src/extent.c
@@ -117,7 +117,7 @@ static void extent_record(tsdn_t *tsdn, arena_t *arena,
 
 /******************************************************************************/
 
-rb_gen(UNUSED, extent_avail_, extent_tree_t, extent_t, rb_link,
+ph_gen(UNUSED, extent_avail_, extent_tree_t, extent_t, ph_link,
     extent_esnead_comp)
 
 typedef enum {