peak mem in INFO backported from unstable branch

src/redis.c

@@ -541,6 +541,10 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
      */
     updateLRUClock();
 
+    /* Record the max memory used since the server was started. */
+    if (zmalloc_used_memory() > server.stat_peak_memory)
+        server.stat_peak_memory = zmalloc_used_memory();
+
     /* We received a SIGTERM, shutting down here in a safe way, as it is
      * not ok doing so inside the signal handler. */
     if (server.shutdown_asap) {
@@ -902,6 +906,7 @@ void initServer() {
     server.stat_starttime = time(NULL);
     server.stat_keyspace_misses = 0;
     server.stat_keyspace_hits = 0;
+    server.stat_peak_memory = 0;
     server.unixtime = time(NULL);
     aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
     if (server.ipfd > 0 && aeCreateFileEvent(server.el,server.ipfd,AE_READABLE,
@@ -1148,7 +1153,7 @@ sds genRedisInfoString(void) {
     sds info;
     time_t uptime = time(NULL)-server.stat_starttime;
     int j;
-    char hmem[64];
+    char hmem[64], peak_hmem[64];
     struct rusage self_ru, c_ru;
     unsigned long lol, bib;
 
@@ -1157,6 +1162,7 @@ sds genRedisInfoString(void) {
     getClientsMaxBuffers(&lol,&bib);
 
     bytesToHuman(hmem,zmalloc_used_memory());
+    bytesToHuman(peak_hmem,server.stat_peak_memory);
     info = sdscatprintf(sdsempty(),
         "redis_version:%s\r\n"
         "redis_git_sha1:%s\r\n"
@@ -1179,6 +1185,8 @@ sds genRedisInfoString(void) {
         "used_memory:%zu\r\n"
         "used_memory_human:%s\r\n"
         "used_memory_rss:%zu\r\n"
+        "used_memory_peak:%zu\r\n"
+        "used_memory_peak_human:%s\r\n"
         "mem_fragmentation_ratio:%.2f\r\n"
         "use_tcmalloc:%d\r\n"
         "loading:%d\r\n"
@@ -1219,6 +1227,8 @@ sds genRedisInfoString(void) {
         zmalloc_used_memory(),
         hmem,
         zmalloc_get_rss(),
+        server.stat_peak_memory,
+        peak_hmem,
         zmalloc_get_fragmentation_ratio(),
 #ifdef USE_TCMALLOC
         1,

src/redis.h

@@ -396,6 +396,7 @@ struct redisServer {
     long long stat_evictedkeys;     /* number of evicted keys (maxmemory) */
     long long stat_keyspace_hits;   /* number of successful lookups of keys */
     long long stat_keyspace_misses; /* number of failed lookups of keys */
+    size_t stat_peak_memory;        /* max used memory record */
     /* Configuration */
     int verbosity;
     int maxidletime;