rt_malloc多次分配后失败

发布于 2016-11-17 18:07:16 浏览：4120 订阅该版

在使用rt_malloc分配10次都可以，后面分配就失败了
但是用list_mem查看内存貌似还有很多，这种情况一般是什么原因导致的，CPU的RAM是64K的
```  | /
- RT -     Thread Operating System
 / |      2.1.0 build Nov 17 2016
 2006 - 2015 Copyright by rt-thread team
finsh>>W25Q128BV detection
flash0 mount to /.

finsh>>list_mem()
total memory: 59760
used memory : 7268
maximum allocated memory: 7268
        0, 0x00000000
finsh>>mem_test(12)
no mem
        0, 0x00000000
finsh>>```
跟踪到rt_malloc内部，发现mem->used的值为0xFFFF

```for (ptr = (rt_uint8_t *)lfree - heap_ptr;
         ptr < mem_size_aligned - size;
         ptr = ((struct heap_mem *)&heap_ptr[ptr])->next)
    {
        mem = (struct heap_mem *)&heap_ptr[ptr];

if ((!mem->used) && (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size)
        {
            /* mem is not used and at least perfect fit is possible:
             * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */

if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >=
                (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED))```
![mem.png](https://oss-club.rt-thread.org/uploads/9774_835a34300063ed88222998cff8879e22.png)

7 个回答

bernard 2016-11-17

这家伙很懒，什么也没写！

aozima 2016-11-17

调网络不抓包，调I2C等时序不上逻辑分析仪，就像电工不用万用表！多用整理的好的文字，比截图更省流量，还能在整理过程中思考。

bernard 2016-11-17

这家伙很懒，什么也没写！

new_os 2016-11-18

这家伙很懒，什么也没写！

这个已经是定义了的页面大小，确实加载了elm文件系统，mkfs提示成功，挂载文件系统成功
测试mkdir时出错，跟踪进去发现是内存分配失败，CPU是GD32F103，64K内存，现在没有加载很多程序，堆内存才分配了2K多
用list_thread看堆栈貌似没有溢出

```
  | /
- RT -     Thread Operating System
 / |      2.1.0 build Nov 18 2016
 2006 - 2015 Copyright by rt-thread team
finsh>>W25Q128BV detection
flash0 mount to /.

finsh>>mkdir("/my_dir")
        -1, 0xffffffff
finsh>>list_thread()
 thread  pri  status      sp     stack size max used   left tick  error
-------- ---- ------- ---------- ---------- ---------- ---------- ---
tidle    0x1f ready   0x00000050 0x00000100 0x00000050 0x0000001b 000
tshell   0x14 ready   0x0000008c 0x00000400 0x000002a8 0x00000006 000
init     0x1d ready   0x00000088 0x00000400 0x00000208 0x00000012 -02
        0, 0x00000000
finsh>>
```

init线程错误代码是-2，线程貌似又可以运行，这个是什么错误？

```

/* SECTION: DFS???????? */
#define RT_USING_DFS

#define RT_USING_DFS_ELMFAT
/* ?????????¨????°???????FatFs???é  */
#define RT_DFS_ELM_REENTRANT
/* ?????????í?¨?????????÷?????????? */
#define RT_DFS_ELM_DRIVES			1
#define RT_DFS_ELM_USE_LFN			0 
#define RT_DFS_ELM_CODE_PAGE		437 
#define RT_DFS_ELM_MAX_LFN			255
/* ?????í??×??ó?????ó?? */
#define RT_DFS_ELM_MAX_SECTOR_SIZE  4096

/* °?×°????????????×??ó???? */
#define DFS_FILESYSTEMS_MAX			1
/* ?ò????????×??ó????		*/
#define DFS_FD_MAX					4
```