diff --git a/fs/procfs/fs_procfsmeminfo.c b/fs/procfs/fs_procfsmeminfo.c
index 924bea2abe..f4c1ab03d0 100644
--- a/fs/procfs/fs_procfsmeminfo.c
+++ b/fs/procfs/fs_procfsmeminfo.c
@@ -516,11 +516,11 @@ static ssize_t memdump_write(FAR struct file *filep, FAR const char *buffer,
   switch (buffer[0])
     {
       case 'u':
-        pid = (pid_t)-1;
+        pid = MM_BACKTRACE_ALLOC_PID;
         break;
 
       case 'f':
-        pid = (pid_t)-2;
+        pid = MM_BACKTRACE_FREE_PID;
         break;
 #if CONFIG_MM_BACKTRACE >= 0
       default:
diff --git a/include/nuttx/mm/mm.h b/include/nuttx/mm/mm.h
index f8788a3dee..3ca86d1e47 100644
--- a/include/nuttx/mm/mm.h
+++ b/include/nuttx/mm/mm.h
@@ -98,6 +98,9 @@
 #  endif
 #endif
 
+#define MM_BACKTRACE_FREE_PID  ((pid_t)-2)
+#define MM_BACKTRACE_ALLOC_PID ((pid_t)-1)
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
diff --git a/mm/mempool/mempool.c b/mm/mempool/mempool.c
index 22aa61ca27..182b3b1193 100644
--- a/mm/mempool/mempool.c
+++ b/mm/mempool/mempool.c
@@ -398,7 +398,7 @@ int mempool_info_task(FAR struct mempool_s *pool,
   irqstate_t flags = spin_lock_irqsave(&pool->lock);
 
   DEBUGASSERT(info);
-  if (info->pid == -2)
+  if (info->pid == MM_BACKTRACE_FREE_PID)
     {
       size_t count = mempool_queue_lenth(&pool->queue) +
                      mempool_queue_lenth(&pool->iqueue);
@@ -411,7 +411,7 @@ int mempool_info_task(FAR struct mempool_s *pool,
           info->uordblks -= pool->totalsize;
         }
     }
-  else if (info->pid == -1)
+  else if (info->pid == MM_BACKTRACE_ALLOC_PID)
     {
 #if CONFIG_MM_BACKTRACE >= 0
       size_t count = list_length(&pool->alist);
@@ -466,7 +466,7 @@ int mempool_info_task(FAR struct mempool_s *pool,
 
 void mempool_memdump(FAR struct mempool_s *pool, pid_t pid)
 {
-  if (pid == -2)
+  if (pid == MM_BACKTRACE_FREE_PID)
     {
       FAR sq_entry_t *entry;
 
@@ -492,7 +492,7 @@ void mempool_memdump(FAR struct mempool_s *pool, pid_t pid)
       list_for_every_entry(&pool->alist, buf, struct mempool_backtrace_s,
                            node)
         {
-          if (buf->pid == pid || pid == -1)
+          if (buf->pid == pid || pid == MM_BACKTRACE_ALLOC_PID)
             {
 #  if CONFIG_MM_BACKTRACE > 0
               int i;
diff --git a/mm/mm_heap/mm_mallinfo.c b/mm/mm_heap/mm_mallinfo.c
index 85dd2e3b74..78f52f4cdb 100644
--- a/mm/mm_heap/mm_mallinfo.c
+++ b/mm/mm_heap/mm_mallinfo.c
@@ -87,16 +87,16 @@ static void mallinfo_task_handler(FAR struct mm_allocnode_s *node,
     {
       DEBUGASSERT(nodesize >= SIZEOF_MM_ALLOCNODE);
 #if CONFIG_MM_BACKTRACE < 0
-      if (info->pid == -1)
+      if (info->pid == MM_BACKTRACE_ALLOC_PID)
 #else
-      if (info->pid == -1 || node->pid == info->pid)
+      if (info->pid == MM_BACKTRACE_ALLOC_PID || node->pid == info->pid)
 #endif
         {
           info->aordblks++;
           info->uordblks += nodesize;
         }
     }
-  else if (info->pid == -2)
+  else if (info->pid == MM_BACKTRACE_FREE_PID)
     {
       info->aordblks++;
       info->uordblks += nodesize;
diff --git a/mm/mm_heap/mm_memdump.c b/mm/mm_heap/mm_memdump.c
index 55c8722abd..6abf0b3b52 100644
--- a/mm/mm_heap/mm_memdump.c
+++ b/mm/mm_heap/mm_memdump.c
@@ -60,9 +60,9 @@ static void memdump_handler(FAR struct mm_allocnode_s *node, FAR void *arg)
     {
       DEBUGASSERT(nodesize >= SIZEOF_MM_ALLOCNODE);
 #if CONFIG_MM_BACKTRACE < 0
-      if (pid == -1)
+      if (pid == MM_BACKTRACE_ALLOC_PID)
 #else
-      if (pid == -1 || node->pid == pid)
+      if (pid == MM_BACKTRACE_ALLOC_PID || node->pid == pid)
 #endif
         {
 #if CONFIG_MM_BACKTRACE < 0
@@ -104,7 +104,7 @@ static void memdump_handler(FAR struct mm_allocnode_s *node, FAR void *arg)
                   SIZEOF_MM_NODE(fnode->flink) == 0 ||
                   SIZEOF_MM_NODE(fnode->flink) >= nodesize);
 
-      if (pid <= -2)
+      if (pid <= MM_BACKTRACE_FREE_PID)
         {
           syslog(LOG_INFO, "%12zu%*p\n",
                  nodesize, MM_PTR_FMT_WIDTH,
diff --git a/mm/tlsf/mm_tlsf.c b/mm/tlsf/mm_tlsf.c
index 7954d5a10c..25b111a163 100644
--- a/mm/tlsf/mm_tlsf.c
+++ b/mm/tlsf/mm_tlsf.c
@@ -263,16 +263,16 @@ static void mallinfo_task_handler(FAR void *ptr, size_t size, int used,
   if (used)
     {
 #if CONFIG_MM_BACKTRACE < 0
-      if (info->pid = -1)
+      if (info->pid = MM_BACKTRACE_ALLOC_PID)
 #else
-      if (info->pid == -1 || info->pid == dump->pid)
+      if (info->pid == MM_BACKTRACE_ALLOC_PID || info->pid == dump->pid)
 #endif
         {
           info->aordblks++;
           info->uordblks += size;
         }
     }
-  else if (info->pid == -2)
+  else if (info->pid == MM_BACKTRACE_FREE_PID)
     {
       info->aordblks++;
       info->uordblks += size;
@@ -377,9 +377,9 @@ static void memdump_handler(FAR void *ptr, size_t size, int used,
   if (used)
     {
 #if CONFIG_MM_BACKTRACE < 0
-      if (pid == -1)
+      if (pid == MM_BACKTRACE_ALLOC_PID)
 #else
-      if (pid == -1 || dump->pid == pid)
+      if (pid == MM_BACKTRACE_ALLOC_PID || dump->pid == pid)
 #endif
         {
 #if CONFIG_MM_BACKTRACE < 0
@@ -406,7 +406,7 @@ static void memdump_handler(FAR void *ptr, size_t size, int used,
 #endif
         }
     }
-  else if (pid <= -2)
+  else if (pid <= MM_BACKTRACE_FREE_PID)
     {
       syslog(LOG_INFO, "%12zu%*p\n", size, MM_PTR_FMT_WIDTH, ptr);
     }
@@ -904,7 +904,7 @@ void mm_memdump(FAR struct mm_heap_s *heap, pid_t pid)
 #endif
   struct memdump_info_s info;
 
-  if (pid >= -1)
+  if (pid >= MM_BACKTRACE_ALLOC_PID)
     {
       syslog(LOG_INFO, "Dump all used memory node info:\n");
 #if CONFIG_MM_BACKTRACE < 0