diff --git a/src/gausskernel/process/postmaster/walwriter.cpp b/src/gausskernel/process/postmaster/walwriter.cpp
index d3d78be75..0f9b6b729 100644
--- a/src/gausskernel/process/postmaster/walwriter.cpp
+++ b/src/gausskernel/process/postmaster/walwriter.cpp
@@ -299,7 +299,7 @@ void WalWriterMain(void)
                 (void)pthread_mutex_lock(&g_instance.wal_cxt.criticalEntryMutex);
                 g_instance.wal_cxt.isWalWriterSleeping = true;
                 while (pCriticalEntry->status == WAL_NOT_COPIED && !t_thrd.walwriter_cxt.shutdown_requested) {
-                    (void)clock_gettime(CLOCK_REALTIME, &time_to_wait);
+                    (void)clock_gettime(CLOCK_MONOTONIC, &time_to_wait);
                     time_to_wait.tv_nsec += g_sleep_timeout_ms * NANOSECONDS_PER_MILLISECOND;
                     if (time_to_wait.tv_nsec >= NANOSECONDS_PER_SECOND) {
                         time_to_wait.tv_nsec -= NANOSECONDS_PER_SECOND;
diff --git a/src/gausskernel/process/threadpool/knl_instance.cpp b/src/gausskernel/process/threadpool/knl_instance.cpp
index c1ab94b2a..409bc9bde 100644
--- a/src/gausskernel/process/threadpool/knl_instance.cpp
+++ b/src/gausskernel/process/threadpool/knl_instance.cpp
@@ -102,6 +102,20 @@ static void knl_g_ckpt_init(knl_g_ckpt_context* ckpt_cxt)
 
 static void knl_g_wal_init(knl_g_wal_context *const wal_cxt)
 {
+    int     ret = 0;
+    ret = pthread_condattr_init(&wal_cxt->criticalEntryAtt);
+    if (ret != 0) {
+        elog(FATAL, "Fail to init conattr for walwrite");
+    }
+    ret = pthread_condattr_setclock(&wal_cxt->criticalEntryAtt, CLOCK_MONOTONIC);
+    if (ret != 0) {
+        elog(FATAL, "Fail to setclock walwrite");
+    }
+    ret = pthread_cond_init(&wal_cxt->criticalEntryCV, &wal_cxt->criticalEntryAtt);
+    if (ret != 0) {
+        elog(FATAL, "Fail to init cond for walwrite");
+    }
+
     wal_cxt->walInsertStatusTable = NULL;
     wal_cxt->walFlushWaitLock = NULL;
     wal_cxt->walBufferInitWaitLock = NULL;
@@ -114,7 +128,6 @@ static void knl_g_wal_init(knl_g_wal_context *const wal_cxt)
     wal_cxt->XLogFlusherCPU = 0;
     wal_cxt->isWalWriterSleeping = false;
     wal_cxt->criticalEntryMutex = PTHREAD_MUTEX_INITIALIZER;
-    wal_cxt->criticalEntryCV = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
     wal_cxt->globalEndPosSegNo = InvalidXLogSegPtr;
     wal_cxt->walWaitFlushCount = 0;
     wal_cxt->lastWalStatusEntryFlushed = -1;
diff --git a/src/include/knl/knl_instance.h b/src/include/knl/knl_instance.h
index 185f1b117..991879186 100644
--- a/src/include/knl/knl_instance.h
+++ b/src/include/knl/knl_instance.h
@@ -698,6 +698,7 @@ typedef struct knl_g_wal_context {
     volatile bool isWalWriterSleeping;
     pthread_mutex_t criticalEntryMutex;
     pthread_cond_t criticalEntryCV;
+    pthread_condattr_t criticalEntryAtt;
     volatile uint32 walWaitFlushCount; /* only for xlog statistics use */
     volatile XLogSegNo globalEndPosSegNo; /* Global variable for init xlog segment files. */
     int lastWalStatusEntryFlushed;