Use the eviction server to write pages with READGEN_OLDEST set.

Even before the eviction trigger has been reached. This should mean
that we clear those pages out of cache earlier, and hopefully will
save application threads from doing the evictions (at least sometimes).

7 files changed, 29 insertions, 7 deletions

diff --git a/src/btree/bt_curnext.c b/src/btree/bt_curnext.c
index 9cd7f0241fc..31d272dc09c 100644
--- a/src/btree/bt_curnext.c
+++ b/src/btree/bt_curnext.c
@@ -483,7 +483,7 @@ __wt_btcur_next(WT_CURSOR_BTREE *cbt, int truncating)
 		if (page != NULL &&
 		    (cbt->page_deleted_count > WT_BTREE_DELETE_THRESHOLD ||
 		    (newpage && cbt->page_deleted_count > 0)))
-			__wt_page_evict_soon(page);
+			__wt_page_evict_soon(session, page);
 		cbt->page_deleted_count = 0;
 
 		WT_ERR(__wt_tree_walk(session, &cbt->ref, flags));
diff --git a/src/btree/bt_curprev.c b/src/btree/bt_curprev.c
index 851b01d3732..e749a5b5b51 100644
--- a/src/btree/bt_curprev.c
+++ b/src/btree/bt_curprev.c
@@ -570,7 +570,7 @@ __wt_btcur_prev(WT_CURSOR_BTREE *cbt, int truncating)
 		if (page != NULL &&
 		    (cbt->page_deleted_count > WT_BTREE_DELETE_THRESHOLD ||
 		    (newpage && cbt->page_deleted_count > 0)))
-			__wt_page_evict_soon(page);
+			__wt_page_evict_soon(session, page);
 		cbt->page_deleted_count = 0;
 
 		WT_ERR(__wt_tree_walk(session, &cbt->ref, flags));
diff --git a/src/btree/bt_page.c b/src/btree/bt_page.c
index 799f0cca3ee..3c92cba709c 100644
--- a/src/btree/bt_page.c
+++ b/src/btree/bt_page.c
@@ -48,7 +48,7 @@ __evict_force_check(WT_SESSION_IMPL *session, WT_PAGE *page)
 		return (0);
 
 	/* Trigger eviction on the next page release. */
-	__wt_page_evict_soon(page);
+	__wt_page_evict_soon(session, page);
 
 	return (1);
 }
@@ -138,7 +138,7 @@ __wt_page_in_func(WT_SESSION_IMPL *session, WT_REF *ref, uint32_t flags
 			 * Otherwise, update the page's read generation.
 			 */
 			if (oldgen && page->read_gen == WT_READGEN_NOTSET)
-				__wt_page_evict_soon(page);
+				__wt_page_evict_soon(session, page);
 			else if (!LF_ISSET(WT_READ_NO_GEN) &&
 			    page->read_gen < __wt_cache_read_gen(session))
 				page->read_gen =
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index dbf3a71f222..2ff7cec9ef6 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -407,6 +407,14 @@ __evict_has_work(WT_SESSION_IMPL *session, uint32_t *flagsp)
 	    (cache->eviction_dirty_target * bytes_max) / 100)
 		/* Ignore clean pages unless the cache is too large */
 		LF_SET(WT_EVICT_PASS_DIRTY);
+	else if (F_ISSET(cache, WT_EVICT_EARLY_CANDIDATES)) {
+		/*
+		 * Trickle out pages with oldest generation set regardless of
+		 * whether we have reached the eviction trigger.
+		 */
+		LF_SET(WT_EVICT_PASS_TRICKLE);
+		F_CLR(cache, WT_EVICT_EARLY_CANDIDATES);
+	}
 
 	if (F_ISSET(cache, WT_EVICT_STUCK))
 		LF_SET(WT_EVICT_PASS_AGGRESSIVE);
@@ -1076,6 +1084,14 @@ __evict_walk_file(WT_SESSION_IMPL *session, u_int *slotp, uint32_t flags)
 		if (F_ISSET_ATOMIC(page, WT_PAGE_EVICT_LRU))
 			continue;
 
+		/*
+		 * If we are only trickling out pages marked for definite
+		 * eviction, skip anything that isn't marked.
+		 */
+		if (LF_ISSET(WT_EVICT_PASS_TRICKLE) &&
+		    page->read_gen != WT_READGEN_OLDEST)
+			continue;
+
 		/* Limit internal pages to 50% unless we get aggressive. */
 		if ((page->type == WT_PAGE_COL_INT ||
 		    page->type == WT_PAGE_ROW_INT) &&
diff --git a/src/include/btree.i b/src/include/btree.i
index 6c42155fefb..d2198a1462d 100644
--- a/src/include/btree.i
+++ b/src/include/btree.i
@@ -227,9 +227,13 @@ __wt_cache_bytes_inuse(WT_CACHE *cache)
  *      Set a page to be evicted as soon as possible.
  */
 static inline void
-__wt_page_evict_soon(WT_PAGE *page)
+__wt_page_evict_soon(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	page->read_gen = WT_READGEN_OLDEST;
+        if (!F_ISSET(S2C(session)->cache, WT_EVICT_EARLY_CANDIDATES)) {
+                F_SET(S2C(session)->cache, WT_EVICT_EARLY_CANDIDATES);
+                (void)__wt_evict_server_wake(session);
+        }
 }
 
 /*
diff --git a/src/include/cache.h b/src/include/cache.h
index a6425e97837..a28204c5582 100644
--- a/src/include/cache.h
+++ b/src/include/cache.h
@@ -19,6 +19,7 @@
 #define	WT_EVICT_PASS_AGGRESSIVE	0x01
 #define	WT_EVICT_PASS_ALL		0x02
 #define	WT_EVICT_PASS_DIRTY		0x04
+#define	WT_EVICT_PASS_TRICKLE		0x08
 
 /*
  * WT_EVICT_ENTRY --
@@ -113,7 +114,8 @@ struct __wt_cache {
 #define	WT_CACHE_POOL_RUN	0x02	/* Cache pool thread running */
 #define	WT_EVICT_ACTIVE		0x04	/* Eviction server is active */
 #define	WT_EVICT_CLEAR_WALKS	0x08	/* Clear eviction walks */
-#define	WT_EVICT_STUCK		0x10	/* Eviction server is stuck */
+#define	WT_EVICT_EARLY_CANDIDATES	0x10	/* Evict before trigger */
+#define	WT_EVICT_STUCK		0x20	/* Eviction server is stuck */
 	uint32_t flags;
 };
 
diff --git a/src/include/cursor.i b/src/include/cursor.i
index 737ac8dcdba..d56f65db0a6 100644
--- a/src/include/cursor.i
+++ b/src/include/cursor.i
@@ -122,7 +122,7 @@ __curfile_leave(WT_CURSOR_BTREE *cbt)
 	 */
 	if (cbt->ref != NULL &&
 	    cbt->page_deleted_count > WT_BTREE_DELETE_THRESHOLD)
-		__wt_page_evict_soon(cbt->ref->page);
+		__wt_page_evict_soon(session, cbt->ref->page);
 	cbt->page_deleted_count = 0;
 
 	/*