Summary:
1.Add configuration to allocate memory from the specified section
2.Replace all memory operations (kmm_) in the vfs with
fs_heap_. When FS_HEAPSIZE > 0, memory is requested for the file system by specifying a configured heap location. By default (i.e. FS_HEAPSIZE=0) fs_heap_ is equivalent to kmm_
Signed-off-by: chenrun1 <chenrun1@xiaomi.com>
For some case, need large files from tmpfs or shmfs, will lead to high
pressure on memory fragments, add an optional fs_heap with independent
heap will benifit for memory fragments issue.
Signed-off-by: buxiasen <buxiasen@xiaomi.com>