extents: Remove preserve_lru feature.

preserve_lru feature adds lots of complication, for little value.
Removing it means merged extents are re-added to the lru list, and may
take longer to madvise away than they otherwise would.

Canaries after removal seem flat for several services (no change).

1 files changed, 18 insertions, 46 deletions

diff --git a/src/extent.c b/src/extent.c
index 88d331f7..f11e77d8 100644
--- a/src/extent.c
+++ b/src/extent.c
@@ -306,8 +306,7 @@ extents_npages_get(extents_t *extents) {
 }
 
 static void
-extents_insert_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent,
-    bool preserve_lru) {
+extents_insert_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent) {
 	malloc_mutex_assert_owner(tsdn, &extents->mtx);
 	assert(extent_state_get(extent) == extents->state);
 
@@ -319,9 +318,7 @@ extents_insert_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent,
 		    (size_t)pind);
 	}
 	extent_heap_insert(&extents->heaps[pind], extent);
-	if (!preserve_lru) {
-		extent_list_append(&extents->lru, extent);
-	}
+	extent_list_append(&extents->lru, extent);
 	size_t npages = size >> LG_PAGE;
 	/*
 	 * All modifications to npages hold the mutex (as asserted above), so we
@@ -335,8 +332,7 @@ extents_insert_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent,
 }
 
 static void
-extents_remove_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent,
-    bool preserve_lru) {
+extents_remove_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent) {
 	malloc_mutex_assert_owner(tsdn, &extents->mtx);
 	assert(extent_state_get(extent) == extents->state);
 
@@ -348,9 +344,7 @@ extents_remove_locked(tsdn_t *tsdn, extents_t *extents, extent_t *extent,
 		bitmap_set(extents->bitmap, &extents_bitmap_info,
 		    (size_t)pind);
 	}
-	if (!preserve_lru) {
-		extent_list_remove(&extents->lru, extent);
-	}
+	extent_list_remove(&extents->lru, extent);
 	size_t npages = size >> LG_PAGE;
 	/*
 	 * As in extents_insert_locked, we hold extents->mtx and so don't need
@@ -500,7 +494,7 @@ extent_try_delayed_coalesce(tsdn_t *tsdn, arena_t *arena,
 	if (!coalesced) {
 		return true;
 	}
-	extents_insert_locked(tsdn, extents, extent, true);
+	extents_insert_locked(tsdn, extents, extent);
 	return false;
 }
 
@@ -560,7 +554,7 @@ extents_evict(tsdn_t *tsdn, arena_t *arena, extent_hooks_t **r_extent_hooks,
 			extent = NULL;
 			goto label_return;
 		}
-		extents_remove_locked(tsdn, extents, extent, false);
+		extents_remove_locked(tsdn, extents, extent);
 		if (!extents->delay_coalesce) {
 			break;
 		}
@@ -633,29 +627,29 @@ extents_postfork_child(tsdn_t *tsdn, extents_t *extents) {
 
 static void
 extent_deactivate_locked(tsdn_t *tsdn, arena_t *arena, extents_t *extents,
-    extent_t *extent, bool preserve_lru) {
+    extent_t *extent) {
 	assert(extent_arena_get(extent) == arena);
 	assert(extent_state_get(extent) == extent_state_active);
 
 	extent_state_set(extent, extents_state_get(extents));
-	extents_insert_locked(tsdn, extents, extent, preserve_lru);
+	extents_insert_locked(tsdn, extents, extent);
 }
 
 static void
 extent_deactivate(tsdn_t *tsdn, arena_t *arena, extents_t *extents,
-    extent_t *extent, bool preserve_lru) {
+    extent_t *extent) {
 	malloc_mutex_lock(tsdn, &extents->mtx);
-	extent_deactivate_locked(tsdn, arena, extents, extent, preserve_lru);
+	extent_deactivate_locked(tsdn, arena, extents, extent);
 	malloc_mutex_unlock(tsdn, &extents->mtx);
 }
 
 static void
 extent_activate_locked(tsdn_t *tsdn, arena_t *arena, extents_t *extents,
-    extent_t *extent, bool preserve_lru) {
+    extent_t *extent) {
 	assert(extent_arena_get(extent) == arena);
 	assert(extent_state_get(extent) == extents_state_get(extents));
 
-	extents_remove_locked(tsdn, extents, extent, preserve_lru);
+	extents_remove_locked(tsdn, extents, extent);
 	extent_state_set(extent, extent_state_active);
 }
 
@@ -905,7 +899,7 @@ extent_recycle_extract(tsdn_t *tsdn, arena_t *arena,
 		return NULL;
 	}
 
-	extent_activate_locked(tsdn, arena, extents, extent, false);
+	extent_activate_locked(tsdn, arena, extents, extent);
 	malloc_mutex_unlock(tsdn, &extents->mtx);
 
 	return extent;
@@ -1031,10 +1025,10 @@ extent_recycle_split(tsdn_t *tsdn, arena_t *arena,
 
 	if (result == extent_split_interior_ok) {
 		if (lead != NULL) {
-			extent_deactivate(tsdn, arena, extents, lead, false);
+			extent_deactivate(tsdn, arena, extents, lead);
 		}
 		if (trail != NULL) {
-			extent_deactivate(tsdn, arena, extents, trail, false);
+			extent_deactivate(tsdn, arena, extents, trail);
 		}
 		return extent;
 	} else {
@@ -1517,34 +1511,15 @@ extent_coalesce(tsdn_t *tsdn, arena_t *arena, extent_hooks_t **r_extent_hooks,
     bool growing_retained) {
 	assert(extent_can_coalesce(arena, extents, inner, outer));
 
-	if (extents->delay_coalesce) {
-		/*
-		 * Remove outer from the LRU list so that it won't be show up in
-		 * decay through extents_evict.
-		 */
-		extent_list_remove(&extents->lru, outer);
-	}
-	extent_activate_locked(tsdn, arena, extents, outer,
-	    extents->delay_coalesce);
+	extent_activate_locked(tsdn, arena, extents, outer);
 
 	malloc_mutex_unlock(tsdn, &extents->mtx);
 	bool err = extent_merge_impl(tsdn, arena, r_extent_hooks,
 	    forward ? inner : outer, forward ? outer : inner, growing_retained);
 	malloc_mutex_lock(tsdn, &extents->mtx);
 
-	if (!err && extents->delay_coalesce) {
-		if (forward) {
-			extent_list_prepend(&extents->lru, inner);
-		} else {
-			extent_list_prepend(&extents->lru, outer);
-		}
-	}
 	if (err) {
-		if (extents->delay_coalesce) {
-			extent_list_prepend(&extents->lru, outer);
-		}
-		extent_deactivate_locked(tsdn, arena, extents, outer,
-		    extents->delay_coalesce);
+		extent_deactivate_locked(tsdn, arena, extents, outer);
 	}
 
 	return err;
@@ -1655,13 +1630,10 @@ extent_record(tsdn_t *tsdn, arena_t *arena, extent_hooks_t **r_extent_hooks,
 			extent = extent_try_coalesce(tsdn, arena,
 			    r_extent_hooks, rtree_ctx, extents, extent,
 			    &coalesced, growing_retained);
-			if (coalesced) {
-				extent_list_remove(&extents->lru, extent);
-			}
 		} while (coalesced &&
 		    extent_size_get(extent) >= prev_size + LARGE_MINCLASS);
 	}
-	extent_deactivate_locked(tsdn, arena, extents, extent, false);
+	extent_deactivate_locked(tsdn, arena, extents, extent);
 
 	malloc_mutex_unlock(tsdn, &extents->mtx);
 }