[linux-mm-cc] [PATCH 08/12] avoid OOM : divide free_chunk_head

[IKEDA Munehiro]

Divide free_chunk_head() into two functions.

One function named __free_chunk_head() is a core part
which puts back all chunks connected to
the chunk_head but doesn't free the chunk_head itself.

Another is free_chunk_head() which calls __free_chunk_head()
and then frees the chunk_head.

This is a preparation for following patches to shrink
ccache area.  Formerly free_chunk_head() was called only
from error path.  The purpose of this patch is to define
a function which can be used by normal path to free chunk_head.

Signed-off-by: IKEDA, Munehiro <m-ikeda at ds.jp.nec.com>
---
 mm/ccache.c |   34 ++++++++++++++++++++++++----------
 1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/mm/ccache.c b/mm/ccache.c
index 3717f1f..ad4fe6f 100644
--- a/mm/ccache.c
+++ b/mm/ccache.c
@@ -287,28 +287,42 @@ repeat:
 }
 
 /*
- * put back all chunks connected to this chunk_head
- * back on free list and free the chunk_head
+ * free_chunk_head() core function but not free the chunk head
  */
-static void free_chunk_head(struct chunk_head *ch)
+static int __free_chunk_head(struct chunk_head *ch)
 {
 	struct chunk *chunk, *tmp;
-	CC_DEBUG("free_chunk_head: chunk_head=%p", ch);
-	if (!ch)
-		return;
+	int freed = 0;
+	
 	chunk = ch->chunk_list;
 
 	/* put back all chunks on free list */
 	while (chunk) {
+		freed += ChunkSize(chunk);
 		tmp = chunk->next;
 		merge_chunk(chunk);
-		spin_lock(&ccache_lock);
-		chunk->next = free_head;
-		free_head = chunk;
-		spin_unlock(&ccache_lock);
 		chunk = tmp;
 	}
+	ch->chunk_list = NULL;
+	return freed;
+}
+
+
+/*
+ * put back all chunks connected to this chunk_head
+ * back on free list and free the chunk_head
+ */
+static int free_chunk_head(struct chunk_head *ch)
+{
+	int freed = 0;
+	
+	CC_DEBUG("free_chunk_head: chunk_head=%p", ch);
+	if (!ch)
+		return 0;
+	freed = __free_chunk_head(ch);
 	kfree(ch);
+
+	return freed;
 }
 
 /*
-- 
1.4.4.4