diff --git a/configure b/configure
index 99ccc1725a..100309c33f 100755
--- a/configure
+++ b/configure
@@ -426,6 +426,7 @@ vxhs=""
 supported_cpu="no"
 supported_os="no"
 bogus_os="no"
+malloc_trim=""
 
 # parse CC options first
 for opt do
@@ -1047,6 +1048,10 @@ for opt do
   ;;
   --enable-tcg) tcg="yes"
   ;;
+  --disable-malloc-trim) malloc_trim="no"
+  ;;
+  --enable-malloc-trim) malloc_trim="yes"
+  ;;
   --disable-spice) spice="no"
   ;;
   --enable-spice) spice="yes"
@@ -1466,6 +1471,7 @@ Advanced options (experts only):
                            Default:trace-<pid>
   --disable-slirp          disable SLIRP userspace network connectivity
   --enable-tcg-interpreter enable TCG with bytecode interpreter (TCI)
+  --enable-malloc-trim     enable libc malloc_trim() for memory optimization
   --oss-lib                path to OSS library
   --cpu=CPU                Build for host CPU [$cpu]
   --with-coroutine=BACKEND coroutine backend. Supported options:
@@ -3860,6 +3866,30 @@ if test "$tcmalloc" = "yes" && test "$jemalloc" = "yes" ; then
     exit 1
 fi
 
+# Even if malloc_trim() is available, these non-libc memory allocators
+# do not support it.
+if test "$tcmalloc" = "yes" || test "$jemalloc" = "yes" ; then
+    if test "$malloc_trim" = "yes" ; then
+        echo "Disabling malloc_trim with non-libc memory allocator"
+    fi
+    malloc_trim="no"
+fi
+
+#######################################
+# malloc_trim
+
+if test "$malloc_trim" != "no" ; then
+    cat > $TMPC << EOF
+#include <malloc.h>
+int main(void) { malloc_trim(0); return 0; }
+EOF
+    if compile_prog "" "" ; then
+        malloc_trim="yes"
+    else
+        malloc_trim="no"
+    fi
+fi
+
 ##########################################
 # tcmalloc probe
 
@@ -5505,6 +5535,7 @@ if test "$tcg" = "yes" ; then
     echo "TCG debug enabled $debug_tcg"
     echo "TCG interpreter   $tcg_interpreter"
 fi
+echo "malloc trim support $malloc_trim"
 echo "RDMA support      $rdma"
 echo "fdt support       $fdt"
 echo "preadv support    $preadv"
@@ -6015,6 +6046,10 @@ if test "$opengl" = "yes" ; then
   fi
 fi
 
+if test "$malloc_trim" = "yes" ; then
+  echo "CONFIG_MALLOC_TRIM=y" >> $config_host_mak
+fi
+
 if test "$avx2_opt" = "yes" ; then
   echo "CONFIG_AVX2_OPT=y" >> $config_host_mak
 fi
diff --git a/util/rcu.c b/util/rcu.c
index ca5a63e36a..f4d09c8304 100644
--- a/util/rcu.c
+++ b/util/rcu.c
@@ -32,6 +32,9 @@
 #include "qemu/atomic.h"
 #include "qemu/thread.h"
 #include "qemu/main-loop.h"
+#if defined(CONFIG_MALLOC_TRIM)
+#include <malloc.h>
+#endif
 
 /*
  * Global grace period counter.  Bit 0 is always one in rcu_gp_ctr.
@@ -246,6 +249,9 @@ static void *call_rcu_thread(void *opaque)
                 qemu_event_reset(&rcu_call_ready_event);
                 n = atomic_read(&rcu_call_count);
                 if (n == 0) {
+#if defined(CONFIG_MALLOC_TRIM)
+                    malloc_trim(4 * 1024 * 1024);
+#endif
                     qemu_event_wait(&rcu_call_ready_event);
                 }
             }