rename reflocked + add protocol.txt line

now lrutail_reflocked.. gross but more descriptive. will still make people
thing something went wrong, oh well.

Author: dormando

doc/protocol.txt

@@ -582,6 +582,8 @@ integers separated by a colon (treat this as a floating point number).
 | slab_reassign_running | bool    | If a slab page is being moved             |
 | slabs_moved           | 64u     | Total slab pages moved                    |
 | crawler_reclaimed     | 64u     | Total items freed by LRU Crawler          |
+| lrutail_reflocked     | 64u     | Times LRU tail was found with active ref. |
+|                       |         | Items moved to head to avoid OOM errors.  |
 |-----------------------+---------+-------------------------------------------|
 
 Settings statistics

items.c

@@ -29,7 +29,7 @@ typedef struct {
     uint64_t expired_unfetched;
     uint64_t evicted_unfetched;
     uint64_t crawler_reclaimed;
-    uint64_t reflocked;
+    uint64_t lrutail_reflocked;
 } itemstats_t;
 
 static item *heads[LARGEST_ID];
@@ -107,7 +107,7 @@ item *do_item_alloc(char *key, const size_t nkey, const int flags,
     /* do a quick check if we have any expired items in the tail.. */
     int tries = 5;
     /* Avoid hangs if a slab has nothing but refcounted stuff in it. */
-    int tries_reflocked = 1000;
+    int tries_lrutail_reflocked = 1000;
     int tried_alloc = 0;
     item *search;
     item *next_it;
@@ -136,10 +136,10 @@ item *do_item_alloc(char *key, const size_t nkey, const int flags,
         if (refcount_incr(&search->refcount) != 2) {
             /* Avoid pathological case with ref'ed items in tail */
             do_item_update_nolock(search);
-            tries_reflocked--;
+            tries_lrutail_reflocked--;
             tries++;
             refcount_decr(&search->refcount);
-            itemstats[id].reflocked++;
+            itemstats[id].lrutail_reflocked++;
             /* Old rare bug could cause a refcount leak. We haven't seen
              * it in years, but we leave this code in to prevent failures
              * just in case */
@@ -152,7 +152,7 @@ item *do_item_alloc(char *key, const size_t nkey, const int flags,
             if (hold_lock)
                 item_trylock_unlock(hold_lock);
 
-            if (tries_reflocked < 1)
+            if (tries_lrutail_reflocked < 1)
                 break;
 
             continue;
@@ -477,7 +477,7 @@ void do_item_stats_totals(ADD_STAT add_stats, void *c) {
         totals.evicted += itemstats[i].evicted;
         totals.reclaimed += itemstats[i].reclaimed;
         totals.crawler_reclaimed += itemstats[i].crawler_reclaimed;
-        totals.reflocked += itemstats[i].reflocked;
+        totals.lrutail_reflocked += itemstats[i].lrutail_reflocked;
     }
     APPEND_STAT("expired_unfetched", "%llu",
                 (unsigned long long)totals.expired_unfetched);
@@ -489,8 +489,8 @@ void do_item_stats_totals(ADD_STAT add_stats, void *c) {
                 (unsigned long long)totals.reclaimed);
     APPEND_STAT("crawler_reclaimed", "%llu",
                 (unsigned long long)totals.crawler_reclaimed);
-    APPEND_STAT("reflocked", "%llu",
-                (unsigned long long)totals.reflocked);
+    APPEND_STAT("lrutail_reflocked", "%llu",
+                (unsigned long long)totals.lrutail_reflocked);
 }
 
 void do_item_stats(ADD_STAT add_stats, void *c) {
@@ -525,8 +525,8 @@ void do_item_stats(ADD_STAT add_stats, void *c) {
                                 "%llu", (unsigned long long)itemstats[i].evicted_unfetched);
             APPEND_NUM_FMT_STAT(fmt, i, "crawler_reclaimed",
                                 "%llu", (unsigned long long)itemstats[i].crawler_reclaimed);
-            APPEND_NUM_FMT_STAT(fmt, i, "reflocked",
-                                "%llu", (unsigned long long)itemstats[i].reflocked);
+            APPEND_NUM_FMT_STAT(fmt, i, "lrutail_reflocked",
+                                "%llu", (unsigned long long)itemstats[i].lrutail_reflocked);
         }
     }
 

t/binary.t

@@ -2,7 +2,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 3603;
+use Test::More tests => 3615;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;

t/refhang.t

@@ -31,11 +31,11 @@ chop $mget;
 my $stats  = mem_stats($sock, "items");
 isnt($stats->{"items:31:evicted"}, "0", "check evicted");
 
-my $reflocked = $stats->{"items:31:reflocked"};
-is($reflocked, "0", "check no slab reflocked");
+my $lrutail_reflocked = $stats->{"items:31:lrutail_reflocked"};
+is($lrutail_reflocked, "0", "check no slab lrutail_reflocked");
 
 $stats = mem_stats($sock);
-is($stats->{"reflocked"}, "0", "check no total reflocked");
+is($stats->{"lrutail_reflocked"}, "0", "check no total lrutail_reflocked");
 
 # Don't intend to read the results, need to fill the socket.
 # TODO: This test would be smarter if we cranked down the socket buffers
@@ -51,10 +51,10 @@ for ($key = 121; $key < 240; $key++) {
 
 $stats = mem_stats($sock, "items");
 is($stats->{"items:31:outofmemory"}, "0", "check no oom");
-isnt($stats->{"items:31:reflocked"}, "0", "count reflocked");
+isnt($stats->{"items:31:lrutail_reflocked"}, "0", "count lrutail_reflocked");
 
 $stats = mem_stats($sock);
-isnt($stats->{"reflocked"}, "0", "count total reflocked");
+isnt($stats->{"lrutail_reflocked"}, "0", "count total lrutail_reflocked");
 
 # Clear out all that 'hung' traffic
 while(<$hangsock> !~ /END/) { };
@@ -69,8 +69,8 @@ print $hangsock2 "get $revkeys\r\n";
 
 for ($key = 240; $key < 260; $key++) {
     print $sock "set key$key 0 0 66560\r\n$value\r\n";
-    is(scalar <$sock>, "SERVER_ERROR out of memory storing object\r\n", "oom fully reflocked");
+    is(scalar <$sock>, "SERVER_ERROR out of memory storing object\r\n", "oom fully lrutail_reflocked");
 }
 
 $stats = mem_stats($sock, "items");
-isnt($stats->{"items:31:outofmemory"}, "0", "count reflocked oom");
+isnt($stats->{"items:31:outofmemory"}, "0", "count lrutail_reflocked oom");

t/stats.t

@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 
 use strict;
-use Test::More tests => 95;
+use Test::More tests => 97;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;
@@ -62,7 +62,7 @@ my $sock = $server->sock;
 ## STAT evictions 0
 ## STAT reclaimed 0
 ## STAT crawler_reclaimed 0
-## STAT reflocked 0
+## STAT lrutail_reflocked 0
 # note that auth stats are tested in auth specfic tests
 
 
@@ -74,7 +74,7 @@ is(scalar(keys(%$stats)), 51, "51 stats values");
 # Test initial state
 foreach my $key (qw(curr_items total_items bytes cmd_get cmd_set get_hits evictions get_misses
                  bytes_written delete_hits delete_misses incr_hits incr_misses decr_hits
-                 decr_misses listen_disabled_num reflocked)) {
+                 decr_misses listen_disabled_num lrutail_reflocked)) {
     is($stats->{$key}, 0, "initial $key is zero");
 }
 is($stats->{accepting_conns}, 1, "initial accepting_conns is one");
@@ -199,7 +199,7 @@ is(0, $stats->{'cas_hits'});
 is(0, $stats->{'cas_badval'});
 is(0, $stats->{'evictions'});
 is(0, $stats->{'reclaimed'});
-is(0, $stats->{'reflocked'});
+is(0, $stats->{'lrutail_reflocked'});
 
 print $sock "flush_all\r\n";
 is(scalar <$sock>, "OK\r\n", "flushed");