According to ext4_mb_group_or_file it's obviously that files larger
than s_mb_stream_request use stream allocator and smaller ones use
locality group allocator.
The original intention for stream allocator had been broken since
commit 4ba74d00a202 ("ext4: Fix bugs in mballoc's stream allocation mode")
and the comments for MB_DEFAULT_STREAM_THRESHOLD became stale.
Signed-off-by: Lin Feng <l...@chinanetcenter.com>
---
fs/ext4/mballoc.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 3ef1df6..2e64c0e 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -59,10 +59,10 @@ extern ushort ext4_mballoc_debug;
#define MB_DEFAULT_STATS 0
/*
- * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
+ * files larger than MB_DEFAULT_STREAM_THRESHOLD are served
* by the stream allocator, which purpose is to pack requests
* as close each to other as possible to produce smooth I/O traffic
- * We use locality group prealloc space for stream request.
+ * We use locality group prealloc space for non stream request.
* We can tune the same via /proc/fs/ext4/<parition>/stream_req
*/
#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
--
1.9.3
