Now that we do not need the new object while holding the highly trafficed

objhead lock, don't preallocate objects.

One unfortunate effect of this preallocation, only recently identified:

On systems with high number of worker threads and high hitrates, considerable
time could elapse between the preallocation of an object to a worker
thread and the use of that object.

This could make cache-misses use a much larger working set size than
really necessary.

I do not have access to any benchmarks that show a credible performance
difference, but reports are most welcome.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3842 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/bin/varnishd/cache.h b/varnish-cache/bin/varnishd/cache.h
index bae7680ba681d3e081095e4b58a2d6d8faad70b3..bd1a155c2263690133148680c34a5e2a8c6960db 100644 (file)
--- a/varnish-cache/bin/varnishd/cache.h
+++ b/varnish-cache/bin/varnishd/cache.h
@@ -194,7 +194,6 @@ struct worker {
        unsigned                magic;
 #define WORKER_MAGIC           0x6391adcf
        struct objhead          *nobjhead;
-       struct object           *nobj;
        struct objcore          *nobjcore;
        struct dstat            *stats;
 

diff --git a/varnish-cache/bin/varnishd/cache_center.c b/varnish-cache/bin/varnishd/cache_center.c
index 216099b2856ddff17625b5c3f2ca1e76ea0211e2..b5ebbb487f1c03f761bc6c11a40398cbd975f056 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_center.c
+++ b/varnish-cache/bin/varnishd/cache_center.c
@@ -314,10 +314,9 @@ cnt_error(struct sess *sp)
        w = sp->wrk;
        if (sp->obj == NULL) {
                HSH_Prealloc(sp);
-               sp->obj = sp->wrk->nobj;
+               sp->obj = HSH_NewObject(sp);
                sp->obj->xid = sp->xid;
                sp->obj->entered = sp->t_req;
-               sp->wrk->nobj = NULL;
        } else {
                /* XXX: Null the headers ? */
        }
@@ -683,8 +682,7 @@ cnt_lookup(struct sess *sp)
                VSL_stats->cache_miss++;
 
                AZ(oc->obj);
-               o = sp->wrk->nobj;
-               sp->wrk->nobj = NULL;
+               o = HSH_NewObject(sp);
 
                o->objhead = oh;
                o->objcore = oc;
@@ -821,8 +819,7 @@ cnt_pass(struct sess *sp)
        assert(sp->handling == VCL_RET_PASS);
        sp->acct_req.pass++;
        HSH_Prealloc(sp);
-       sp->obj = sp->wrk->nobj;
-       sp->wrk->nobj = NULL;
+       sp->obj = HSH_NewObject(sp);
        sp->sendbody = 1;
        sp->step = STP_FETCH;
        return (0);
@@ -1078,7 +1075,6 @@ CNT_Session(struct sess *sp)
                CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
                CHECK_OBJ_ORNULL(sp->obj, OBJECT_MAGIC);
                CHECK_OBJ_NOTNULL(sp->wrk, WORKER_MAGIC);
-               CHECK_OBJ_ORNULL(w->nobj, OBJECT_MAGIC);
                CHECK_OBJ_ORNULL(w->nobjhead, OBJHEAD_MAGIC);
 
                switch (sp->step) {
@@ -1093,7 +1089,6 @@ CNT_Session(struct sess *sp)
                default:
                        WRONG("State engine misfire");
                }
-               CHECK_OBJ_ORNULL(w->nobj, OBJECT_MAGIC);
                CHECK_OBJ_ORNULL(w->nobjhead, OBJHEAD_MAGIC);
        }
        WSL_Flush(w, 0);

diff --git a/varnish-cache/bin/varnishd/cache_hash.c b/varnish-cache/bin/varnishd/cache_hash.c
index 599f8e732fc1b0377e6f185d3e8a3b8cd0850007..fc1d3629dc2b4aa295531a0c6bbf4aaca681e70b 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_hash.c
+++ b/varnish-cache/bin/varnishd/cache_hash.c
@@ -79,15 +79,42 @@ HSH_Grace(double g)
        return (g);
 }
 
+struct object *
+HSH_NewObject(struct sess *sp)
+{
+       struct object *o;
+       struct storage *st;
+
+       st = STV_alloc(sp, params->obj_workspace);
+       XXXAN(st);
+       assert(st->space > sizeof *o);
+       o = (void *)st->ptr; /* XXX: align ? */
+       st->len = sizeof *o;
+       memset(o, 0, sizeof *o);
+       o->objstore = st;
+       WS_Init(o->ws_o, "obj",
+           st->ptr + st->len, st->space - st->len);
+       st->len = st->space;
+       WS_Assert(o->ws_o);
+       http_Setup(o->http, o->ws_o);
+       o->magic = OBJECT_MAGIC;
+       o->http->magic = HTTP_MAGIC;
+       o->refcnt = 1;
+       o->grace = NAN;
+       o->entered = NAN;
+       VTAILQ_INIT(&o->store);
+       VTAILQ_INIT(&o->esibits);
+       sp->wrk->stats->n_object++;
+       return (o);
+}
+
 /* Precreate an objhead and object for later use */
 void
-HSH_Prealloc(struct sess *sp)
+HSH_Prealloc(const struct sess *sp)
 {
        struct worker *w;
        struct objhead *oh;
        struct objcore *oc;
-       struct object *o;
-       struct storage *st;
 
        CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
        CHECK_OBJ_NOTNULL(sp->wrk, WORKER_MAGIC);
@@ -113,31 +140,6 @@ HSH_Prealloc(struct sess *sp)
        }
        CHECK_OBJ_NOTNULL(w->nobjhead, OBJHEAD_MAGIC);
 
-       if (w->nobj == NULL) {
-               st = STV_alloc(sp, params->obj_workspace);
-               XXXAN(st);
-               assert(st->space > sizeof *w->nobj);
-               o = (void *)st->ptr; /* XXX: align ? */
-               st->len = sizeof *o;
-               memset(o, 0, sizeof *o);
-               o->objstore = st;
-               WS_Init(o->ws_o, "obj",
-                   st->ptr + st->len, st->space - st->len);
-               st->len = st->space;
-               WS_Assert(o->ws_o);
-               http_Setup(o->http, o->ws_o);
-               o->magic = OBJECT_MAGIC;
-               o->http->magic = HTTP_MAGIC;
-               o->refcnt = 1;
-               o->grace = NAN;
-               o->entered = NAN;
-               VTAILQ_INIT(&o->store);
-               VTAILQ_INIT(&o->esibits);
-               w->nobj = o;
-               w->stats->n_object++;
-
-       }
-       CHECK_OBJ_NOTNULL(w->nobj, OBJECT_MAGIC);
 }
 
 void
@@ -154,11 +156,6 @@ HSH_Cleanup(struct worker *w)
                w->nobjhead = NULL;
                w->stats->n_objecthead--;
        }
-       if (w->nobj != NULL) {
-               STV_free(w->nobj->objstore);
-               w->nobj = NULL;
-               w->stats->n_object--;
-       }
 }
 
 void

diff --git a/varnish-cache/bin/varnishd/cache_pool.c b/varnish-cache/bin/varnishd/cache_pool.c
index a45a7300eada578748c7304444a7ccc5176a6a27..8157fa3447080046fda769478a89d8ed84adb748 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_pool.c
+++ b/varnish-cache/bin/varnishd/cache_pool.c
@@ -431,10 +431,8 @@ wrk_do_cnt_sess(struct worker *w, void *priv)
        AZ(sess->wrk);
        THR_SetSession(sess);
        sess->wrk = w;
-       CHECK_OBJ_ORNULL(w->nobj, OBJECT_MAGIC);
        CHECK_OBJ_ORNULL(w->nobjhead, OBJHEAD_MAGIC);
        CNT_Session(sess);
-       CHECK_OBJ_ORNULL(w->nobj, OBJECT_MAGIC);
        CHECK_OBJ_ORNULL(w->nobjhead, OBJHEAD_MAGIC);
        THR_SetSession(NULL);
 }

diff --git a/varnish-cache/bin/varnishd/hash_slinger.h b/varnish-cache/bin/varnishd/hash_slinger.h
index 1e764613412ab662fde236a4abca3bf52e0d5fe1..e86345704343d7ac8437c2684ab738dfba72cd87 100644 (file)
--- a/varnish-cache/bin/varnishd/hash_slinger.h
+++ b/varnish-cache/bin/varnishd/hash_slinger.h
@@ -50,7 +50,8 @@ struct hash_slinger {
 };
 
 /* cache_hash.c */
-void HSH_Prealloc(struct sess *sp);
+struct object *HSH_NewObject(struct sess *sp);
+void HSH_Prealloc(const struct sess *sp);
 void HSH_Cleanup(struct worker *w);
 void HSH_Freestore(struct object *o);
 void HSH_Copy(const struct sess *sp, struct objhead *o);