[master] 175cac7 LRU code polishing

[Poul-Henning Kamp]

commit 175cac7ef3a1e68d8ed0f4bd41cc2177d43233d6
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Thu Feb 4 11:04:06 2016 +0000

    LRU code polishing

diff --git a/bin/varnishd/storage/storage.h b/bin/varnishd/storage/storage.h
index d63b82b..5e0d78f 100644
--- a/bin/varnishd/storage/storage.h
+++ b/bin/varnishd/storage/storage.h
@@ -119,14 +119,14 @@ int STV_GetFile(const char *fn, int *fdp, const char **fnp, const char *ctx);
 uintmax_t STV_FileSize(int fd, const char *size, unsigned *granularity,
     const char *ctx);
 
+/*--------------------------------------------------------------------*/
 struct lru *LRU_Alloc(void);
 void LRU_Free(struct lru *);
-void LRU_Add(struct objcore *);
+void LRU_Add(struct objcore *, double now);
 void LRU_Remove(struct objcore *);
 int LRU_NukeOne(struct worker *, struct lru *);
 void LRU_Touch(struct worker *, struct objcore *, double now);
 
-
 /*--------------------------------------------------------------------*/
 extern const struct stevedore sma_stevedore;
 extern const struct stevedore smf_stevedore;
diff --git a/bin/varnishd/storage/storage_lru.c b/bin/varnishd/storage/storage_lru.c
index 0acb91d..0fbfb36 100644
--- a/bin/varnishd/storage/storage_lru.c
+++ b/bin/varnishd/storage/storage_lru.c
@@ -25,22 +25,17 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * STEVEDORE: one who works at or is responsible for loading and
- * unloading ships in port.  Example: "on the wharves, stevedores were
- * unloading cargo from the far corners of the world." Origin: Spanish
- * estibador, from estibar to pack.  First Known Use: 1788
+ * Least-Recently-Used logic for freeing space in stevedores.
  */
 
 #include "config.h"
 
-#include <stdio.h>
 #include <stdlib.h>
 
 #include "cache/cache.h"
 #include "hash/hash_slinger.h"
 
 #include "storage/storage.h"
-#include "vtim.h"
 
 struct lru {
 	unsigned		magic;
@@ -70,16 +65,17 @@ LRU_Free(struct lru *lru)
 }
 
 void
-LRU_Add(struct objcore *oc)
+LRU_Add(struct objcore *oc, double now)
 {
 	struct lru *lru;
 
 	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
+	AZ(isnan(now));
 	lru = ObjGetLRU(oc);
 	CHECK_OBJ_NOTNULL(lru, LRU_MAGIC);
 	Lck_Lock(&lru->mtx);
 	VTAILQ_INSERT_TAIL(&lru->lru_head, oc, lru_list);
-	oc->last_lru = VTIM_real();
+	oc->last_lru = now;
 	Lck_Unlock(&lru->mtx);
 }
 
@@ -139,7 +135,7 @@ LRU_Touch(struct worker *wrk, struct objcore *oc, double now)
 /*--------------------------------------------------------------------
  * Attempt to make space by nuking the oldest object on the LRU list
  * which isn't in use.
- * Returns: 1: did, 0: didn't, -1: can't
+ * Returns: 1: did, 0: didn't;
  */
 
 int
@@ -170,7 +166,7 @@ LRU_NukeOne(struct worker *wrk, struct lru *lru)
 
 	if (oc == NULL) {
 		VSLb(wrk->vsl, SLT_ExpKill, "LRU_Fail");
-		return (-1);
+		return (0);
 	}
 
 	/* XXX: We could grab and return one storage segment to our caller */
diff --git a/bin/varnishd/storage/storage_persistent.c b/bin/varnishd/storage/storage_persistent.c
index 735c7c5..f405755 100644
--- a/bin/varnishd/storage/storage_persistent.c
+++ b/bin/varnishd/storage/storage_persistent.c
@@ -531,7 +531,7 @@ smp_allocobj(struct worker *wrk, const struct stevedore *stv,
 
 	while (1) {
 		if (really > 0) {
-			if (LRU_NukeOne(wrk, stv->lru) == -1)
+			if (!LRU_NukeOne(wrk, stv->lru))
 				return (0);
 			really--;
 		}
diff --git a/bin/varnishd/storage/storage_simple.c b/bin/varnishd/storage/storage_simple.c
index 95f4c05..b02846e 100644
--- a/bin/varnishd/storage/storage_simple.c
+++ b/bin/varnishd/storage/storage_simple.c
@@ -128,7 +128,7 @@ SML_allocobj(struct worker *wrk, const struct stevedore *stv,
 	ltot = sizeof(struct object) + PRNDUP(wsl);
 	while (1) {
 		if (really > 0) {
-			if (LRU_NukeOne(wrk, stv->lru) == -1)
+			if (!LRU_NukeOne(wrk, stv->lru))
 				return (0);
 			really--;
 		}
@@ -339,7 +339,7 @@ objallocwithnuke(struct worker *wrk, const struct stevedore *stv, size_t size)
 
 		/* no luck; try to free some space and keep trying */
 		if (fail < cache_param->nuke_limit &&
-		    LRU_NukeOne(wrk, stv->lru) == -1)
+		    !LRU_NukeOne(wrk, stv->lru))
 			break;
 	}
 	CHECK_OBJ_ORNULL(st, STORAGE_MAGIC);
@@ -505,7 +505,7 @@ sml_stable(struct worker *wrk, struct objcore *oc, struct boc *boc)
 		sml_stv_free(stv, st);
 	}
 
-	LRU_Add(oc);
+	LRU_Add(oc, wrk->lastused);	// approx timestamp is OK
 }
 
 static void * __match_proto__(objgetattr_f)