mm: add memory pressure notification support

Add mm_heap_free interface to pass remaining memory to memory pressure

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>

arch/sim/src/sim/sim_heap.c

@@ -611,6 +611,18 @@ void up_allocate_heap(void **heap_start, size_t *heap_size)
   *heap_size  = 0;
 }
 
+/****************************************************************************
+ * Name: mm_heapfree
+ *
+ * Description:
+ *   Return the total free size (in bytes) in the heap
+ *
+ ****************************************************************************/
+
+size_t mm_heapfree(struct mm_heap_s *heap)
+{
+  return SIZE_MAX;
+}
 #else /* CONFIG_MM_CUSTOMIZE_MANAGER */
 
 void up_allocate_heap(void **heap_start, size_t *heap_size)

fs/procfs/fs_procfspressure.c

@@ -159,19 +159,25 @@ static ssize_t pressure_read(FAR struct file *filep, FAR char *buffer,
 {
   char buf[128];
   uint32_t flags;
+  size_t remain;
+  off_t offset;
   ssize_t ret;
 
   flags  = spin_lock_irqsave(&g_pressure_lock);
-  ret = procfs_snprintf(buf, sizeof(buf), "remaining %zu\n",
+  remain = g_remaining;
-                        g_remaining);
   spin_unlock_irqrestore(&g_pressure_lock, flags);
 
+  ret = procfs_snprintf(buf, sizeof(buf), "remaining %zu\n", remain);
+
   if (ret > buflen)
     {
       return -ENOMEM;
     }
 
-  memcpy(buffer, buf, ret);
+  offset = filep->f_pos;
+  ret    = procfs_memcpy(buf, ret, buffer, buflen, &offset);
+
+  filep->f_pos += ret;
   return ret;
 }
 

include/nuttx/mm/mm.h

@@ -389,6 +389,8 @@ struct mallinfo mm_mallinfo(FAR struct mm_heap_s *heap);
 struct mallinfo_task mm_mallinfo_task(FAR struct mm_heap_s *heap,
                                       FAR const struct malltask *task);
 
+size_t mm_heapfree(FAR struct mm_heap_s *heap);
+
 /* Functions contained in kmm_mallinfo.c ************************************/
 
 #ifdef CONFIG_MM_KERNEL_HEAP

mm/mm_heap/mm_mallinfo.c

@@ -187,3 +187,16 @@ struct mallinfo_task mm_mallinfo_task(FAR struct mm_heap_s *heap,
 
   return info;
 }
+
+/****************************************************************************
+ * Name: mm_heapfree
+ *
+ * Description:
+ *   Return the total free size (in bytes) in the heap
+ *
+ ****************************************************************************/
+
+size_t mm_heapfree(FAR struct mm_heap_s *heap)
+{
+  return heap->mm_heapsize - heap->mm_curused;
+}

mm/tlsf/mm_tlsf.c

@@ -1463,3 +1463,16 @@ void mm_free_delaylist(FAR struct mm_heap_s *heap)
        free_delaylist(heap, true);
     }
 }
+
+/****************************************************************************
+ * Name: mm_heapfree
+ *
+ * Description:
+ *   Return the total free size (in bytes) in the heap
+ *
+ ****************************************************************************/
+
+size_t mm_heapfree(FAR struct mm_heap_s *heap)
+{
+  return heap->mm_heapsize - heap->mm_curused;
+}

mm/umm_heap/umm_calloc.c

@@ -70,6 +70,17 @@ FAR void *calloc(size_t n, size_t elem_size)
 #else
   /* Use mm_calloc() because it implements the clear */
 
-  return mm_calloc(USR_HEAP, n, elem_size);
+  FAR void *mem = mm_calloc(USR_HEAP, n, elem_size);
+
+  if (mem == NULL)
+    {
+      set_errno(ENOMEM);
+    }
+  else
+    {
+      mm_notify_pressure(mm_heapfree(USR_HEAP));
+    }
+
+  return mem;
 #endif
 }

mm/umm_heap/umm_malloc.c

@@ -66,6 +66,10 @@ FAR void *malloc(size_t size)
     {
       set_errno(ENOMEM);
     }
+  else
+    {
+      mm_notify_pressure(mm_heapfree(USR_HEAP));
+    }
 
   return ret;
 #endif

mm/umm_heap/umm_memalign.c

@@ -93,6 +93,10 @@ FAR void *memalign(size_t alignment, size_t size)
     {
       set_errno(ENOMEM);
     }
+  else
+    {
+      mm_notify_pressure(mm_heapfree(USR_HEAP));
+    }
 
   return ret;
 #endif

mm/umm_heap/umm_realloc.c

@@ -95,6 +95,10 @@ FAR void *realloc(FAR void *oldmem, size_t size)
     {
       set_errno(ENOMEM);
     }
+  else
+    {
+      mm_notify_pressure(mm_heapfree(USR_HEAP));
+    }
 
   return ret;
 #endif

mm/umm_heap/umm_zalloc.c

@@ -72,6 +72,10 @@ FAR void *zalloc(size_t size)
     {
       set_errno(ENOMEM);
     }
+  else
+    {
+      mm_notify_pressure(mm_heapfree(USR_HEAP));
+    }
 
   return ret;
 #endif