[incubator-nuttx] branch master updated: mm/mm_heap: place alloc-bit at the LSB of node->preceeding.

[pk...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

pkarashchenko pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new a0bde21  mm/mm_heap: place alloc-bit at the LSB of node->preceeding.
a0bde21 is described below

commit a0bde21f0f2b8694cf3f60efe1e665dc15c340e5
Author: wangbowen6 <wa...@xiaomi.com>
AuthorDate: Wed Mar 30 20:31:29 2022 +0800

    mm/mm_heap: place alloc-bit at the LSB of node->preceeding.
    
    Heap always allocate the memory at least 2bytes alignment.
    
    Signed-off-by: wangbowen6 <wa...@xiaomi.com>
---
 mm/mm_heap/mm.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/mm_heap/mm.h b/mm/mm_heap/mm.h
index af89268..9ea235e 100644
--- a/mm/mm_heap/mm.h
+++ b/mm/mm_heap/mm.h
@@ -124,15 +124,14 @@
 #define MM_ALIGN_UP(a)   (((a) + MM_GRAN_MASK) & ~MM_GRAN_MASK)
 #define MM_ALIGN_DOWN(a) ((a) & ~MM_GRAN_MASK)
 
-/* An allocated chunk is distinguished from a free chunk by bit 31 (or 15)
+/* An allocated chunk is distinguished from a free chunk by bit 0
  * of the 'preceding' chunk size.  If set, then this is an allocated chunk.
  */
 
+#define MM_ALLOC_BIT     0x1
 #ifdef CONFIG_MM_SMALL
-# define MM_ALLOC_BIT    0x8000
 # define MMSIZE_MAX      UINT16_MAX
 #else
-# define MM_ALLOC_BIT    0x80000000
 # define MMSIZE_MAX      UINT32_MAX
 #endif