diff --git a/deps/jemalloc-5.2.1/include/jemalloc/internal/jemalloc_internal_inlines_c.h b/deps/jemalloc-5.2.1/include/jemalloc/internal/jemalloc_internal_inlines_c.h
index cdb10eb2..17b2472f 100644
--- a/deps/jemalloc-5.2.1/include/jemalloc/internal/jemalloc_internal_inlines_c.h
+++ b/deps/jemalloc-5.2.1/include/jemalloc/internal/jemalloc_internal_inlines_c.h
@@ -219,4 +219,32 @@ ixalloc(tsdn_t *tsdn, void *ptr, size_t oldsize, size_t size, size_t extra,
 	    newsize);
 }
 
+JEMALLOC_ALWAYS_INLINE int
+iget_defrag_hint(tsdn_t *tsdn, void* ptr, int *bin_util, int *run_util) {
+	int defrag = 0;
+	rtree_ctx_t rtree_ctx_fallback;
+	rtree_ctx_t *rtree_ctx = tsdn_rtree_ctx(tsdn, &rtree_ctx_fallback);
+	szind_t szind;
+	bool is_slab;
+	rtree_szind_slab_read(tsdn, &extents_rtree, rtree_ctx, (uintptr_t)ptr, true, &szind, &is_slab);
+	if (likely(is_slab)) {
+		/* Small allocation. */
+		extent_t *slab = iealloc(tsdn, ptr);
+		arena_t *arena = extent_arena_get(slab);
+		szind_t binind = extent_szind_get(slab);
+		bin_t *bin = &arena->bins[binind];
+		malloc_mutex_lock(tsdn, &bin->lock);
+		/* don't bother moving allocations from the slab currently used for new allocations */
+		if (slab != bin->slabcur) {
+			const bin_info_t *bin_info = &bin_infos[binind];
+			size_t availregs = bin_info->nregs * bin->stats.curslabs;
+			*bin_util = ((long long)bin->stats.curregs<<16) / availregs;
+			*run_util = ((long long)(bin_info->nregs - extent_nfree_get(slab))<<16) / bin_info->nregs;
+			defrag = 1;
+		}
+		malloc_mutex_unlock(tsdn, &bin->lock);
+	}
+	return defrag;
+}
+
 #endif /* JEMALLOC_INTERNAL_INLINES_C_H */
diff --git a/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h b/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h
index 34235894..26aa9908 100644
--- a/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h
+++ b/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h
@@ -127,3 +127,7 @@
 #  define JEMALLOC_RESTRICT_RETURN
 #  define JEMALLOC_ALLOCATOR
 #endif
+
+/* This version of Jemalloc, modified for Redis, has the je_get_defrag_hint()
+ * function. */
+#define JEMALLOC_FRAG_HINT
diff --git a/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h.in b/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h.in
index 59e29558..3421321a 100644
--- a/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h.in
+++ b/deps/jemalloc-5.2.1/include/jemalloc/jemalloc_macros.h.in
@@ -127,3 +127,7 @@
 #  define JEMALLOC_RESTRICT_RETURN
 #  define JEMALLOC_ALLOCATOR
 #endif
+
+/* This version of Jemalloc, modified for Redis, has the je_get_defrag_hint()
+ * function. */
+#define JEMALLOC_FRAG_HINT
diff --git a/deps/jemalloc-5.2.1/src/jemalloc.c b/deps/jemalloc-5.2.1/src/jemalloc.c
index ed13718d..3447ebe1 100644
--- a/deps/jemalloc-5.2.1/src/jemalloc.c
+++ b/deps/jemalloc-5.2.1/src/jemalloc.c
@@ -3920,3 +3920,15 @@ jemalloc_postfork_child(void) {
 }
 
 /******************************************************************************/
+
+
+/* Helps the application decide if a pointer is worth re-allocating in order to reduce fragmentation.
+ * returns 0 if the allocation is in the currently active run,
+ * or when it is not causing any frag issue (large or huge bin)
+ * returns the bin utilization and run utilization both in fixed point 16:16.
+ * If the application decides to re-allocate it should use MALLOCX_TCACHE_NONE when doing so. */
+JEMALLOC_EXPORT int JEMALLOC_NOTHROW
+je_get_defrag_hint(void* ptr, int *bin_util, int *run_util) {
+	assert(ptr != NULL);
+	return iget_defrag_hint(TSDN_NULL, ptr, bin_util, run_util);
+}
diff --git a/msvs/RedisServer.vcxproj b/msvs/RedisServer.vcxproj
index c1f41617..0967bb38 100644
--- a/msvs/RedisServer.vcxproj
+++ b/msvs/RedisServer.vcxproj
@@ -95,7 +95,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <ClCompile>
-      <PreprocessorDefinitions>USE_JEMALLOC;_OFF_T_DEFINED;WIN32;LACKS_STDLIB_H;_DEBUG;_CONSOLE;__x86_64__;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>USE_JEMALLOC;JEMALLOC_FRAG_HINT;_OFF_T_DEFINED;WIN32;LACKS_STDLIB_H;_DEBUG;_CONSOLE;__x86_64__;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(SolutionDir)..\deps\lua\src;$(SolutionDir)..\deps\geohash-int;$(SolutionDir);..\deps\hiredis;..\deps\jemalloc-5.2.1\include;..\deps\jemalloc-5.2.1\include\msvc_compat</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <WarningLevel>Level3</WarningLevel>
@@ -143,7 +143,7 @@ copy /Y $(OutputPath)redis-server.pdb $(OutputPath)redis-check-aof.pdb</Command>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>
-      <PreprocessorDefinitions>USE_JEMALLOC;_OFF_T_DEFINED;WIN32;LACKS_STDLIB_H;NDEBUG;_CONSOLE;__x86_64__;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>USE_JEMALLOC;JEMALLOC_FRAG_HINT;_OFF_T_DEFINED;WIN32;LACKS_STDLIB_H;NDEBUG;_CONSOLE;__x86_64__;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(SolutionDir)..\deps\lua\src;$(SolutionDir)..\deps\geohash-int;$(SolutionDir);..\deps\hiredis;$(SolutionDir)..\deps\jemalloc-5.2.1\include;$(SolutionDir)..\deps\jemalloc-5.2.1\include\msvc_compat</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <WarningLevel>Level3</WarningLevel>
diff --git a/src/zmalloc.h b/src/zmalloc.h
index 47bac065..1bcbb4ae 100644
--- a/src/zmalloc.h
+++ b/src/zmalloc.h
@@ -51,7 +51,7 @@
 #endif
 
 #elif defined(USE_JEMALLOC)
-#define ZMALLOC_LIB ("jemalloc-" __xstr(JEMALLOC_VERSION_MAJOR) "." __xstr(JEMALLOC_VERSION_MINOR) "." __xstr(JEMALLOC_VERSION_BUGFIX))
+#define ZMALLOC_LIB ("jemalloc-" __xstr(JEMALLOC_VERSION_MAJOR) "." __xstr(JEMALLOC_VERSION_MINOR) "." __xstr(JEMALLOC_VERSION_BUGFIX) "-redis")
 #include <jemalloc/jemalloc.h>
 #if (JEMALLOC_VERSION_MAJOR == 2 && JEMALLOC_VERSION_MINOR >= 1) || (JEMALLOC_VERSION_MAJOR > 2)
 #define HAVE_MALLOC_SIZE 1