automove levels are an int instead of bool now

also fix a bug causing slab rebalance thread to spin instead of waiting on the
condition... duhr.

4 files changed, 33 insertions, 12 deletions

diff --git a/items.c b/items.c
index ab588db..6546f88 100644
--- a/items.c
+++ b/items.c
@@ -146,6 +146,16 @@ item *do_item_alloc(char *key, const size_t nkey, const int flags, const rel_tim
             do_item_unlink_nolock(it, hash(ITEM_key(it), it->nkey, 0));
             /* Initialize the item block: */
             it->slabs_clsid = 0;
+
+            /* If we've just evicted an item, and the automover is set to
+             * angry bird mode, attempt to rip memory into this slab class.
+             * TODO: Move valid object detection into a function, and on a
+             * "successful" memory pull, look behind and see if the next alloc
+             * would be an eviction. Then kick off the slab mover before the
+             * eviction happens.
+             */
+            if (settings.slab_automove == 2)
+                slabs_reassign(-1, id);
         } else {
             refcount_decr(&search->refcount);
         }
diff --git a/memcached.c b/memcached.c
index e1ea9cd..cd7abbb 100644
--- a/memcached.c
+++ b/memcached.c
@@ -224,7 +224,7 @@ static void settings_init(void) {
     settings.maxconns_fast = false;
     settings.hashpower_init = 0;
     settings.slab_reassign = false;
-    settings.slab_automove = false;
+    settings.slab_automove = 0;
 }
 
 /*
@@ -2624,7 +2624,7 @@ static void process_stat_settings(ADD_STAT add_stats, void *c) {
     APPEND_STAT("maxconns_fast", "%s", settings.maxconns_fast ? "yes" : "no");
     APPEND_STAT("hashpower_init", "%d", settings.hashpower_init);
     APPEND_STAT("slab_reassign", "%s", settings.slab_reassign ? "yes" : "no");
-    APPEND_STAT("slab_automove", "%s", settings.slab_automove ? "yes" : "no");
+    APPEND_STAT("slab_automove", "%d", settings.slab_automove);
 }
 
 static void process_stat(conn *c, token_t *tokens, const size_t ntokens) {
@@ -3206,9 +3206,9 @@ static void process_slabs_automove_command(conn *c, token_t *tokens, const size_
 
     level = strtoul(tokens[2].value, NULL, 10);
     if (level == 0) {
-        settings.slab_automove = false;
-    } else if (level == 1) {
-        settings.slab_automove = true;
+        settings.slab_automove = 0;
+    } else if (level == 1 || level == 2) {
+        settings.slab_automove = level;
     } else {
         out_string(c, "ERROR");
         return;
@@ -4980,7 +4980,15 @@ int main (int argc, char **argv) {
                 settings.slab_reassign = true;
                 break;
             case SLAB_AUTOMOVE:
-                settings.slab_automove = true;
+                if (subopts_value == NULL) {
+                    settings.slab_automove = 1;
+                    break;
+                }
+                settings.slab_automove = atoi(subopts_value);
+                if (settings.slab_automove < 0 || settings.slab_automove > 2) {
+                    fprintf(stderr, "slab_automove must be between 0 and 2\n");
+                    return 1;
+                }
                 break;
             default:
                 printf("Illegal suboption \"%s\"\n", subopts_value);
diff --git a/memcached.h b/memcached.h
index 97a79d0..17bfd71 100644
--- a/memcached.h
+++ b/memcached.h
@@ -301,7 +301,7 @@ struct settings {
     bool sasl;              /* SASL on/off */
     bool maxconns_fast;     /* Whether or not to early close connections */
     bool slab_reassign;     /* Whether or not slab reassignment is allowed */
-    bool slab_automove;     /* Whether or not to automatically move slabs */
+    int slab_automove;     /* Whether or not to automatically move slabs */
     int hashpower_init;     /* Starting hash power level */
 };
 
diff --git a/slabs.c b/slabs.c
index cf8dd0c..2503381 100644
--- a/slabs.c
+++ b/slabs.c
@@ -734,7 +734,7 @@ static void *slab_maintenance_thread(void *arg) {
     int src, dest;
 
     while (do_run_slab_thread) {
-        if (settings.slab_automove) {
+        if (settings.slab_automove == 1) {
             if (slab_automove_decision(&src, &dest) == 1) {
                 /* Blind to the return codes. It will retry on its own */
                 slabs_reassign(src, dest);
@@ -769,6 +769,13 @@ static void *slab_rebalance_thread(void *arg) {
 
         if (slab_rebal.done) {
             slab_rebalance_finish();
+        } else if (was_busy) {
+            /* Stuck waiting for some items to unlock, so slow down a bit
+             * to give them a chance to free up */
+            usleep(50);
+        }
+
+        if (slab_rebalance_signal == 0) {
             /* Wrap the conditional with slabs_lock so we can't accidentally miss
              * a signal */
             /* FIXME: Technically there's a race between
@@ -777,10 +784,6 @@ static void *slab_rebalance_thread(void *arg) {
             mutex_lock(&slabs_lock);
             pthread_cond_wait(&slab_rebalance_cond, &slabs_lock);
             pthread_mutex_unlock(&slabs_lock);
-        } else if (was_busy) {
-            /* Stuck waiting for some items to unlock, so slow down a bit
-             * to give them a chance to free up */
-            usleep(50);
         }
     }
     return NULL;