ext4: Use slab allocator for sub-page sized allocations

Now that the SLUB seems to be fixed so that it respects the requested
alignment, use kmem_cache_alloc() to allocator if the block size of
the buffer heads to be allocated is less than the page size.
Previously, we were using 16k page on a Power system for each buffer,
even when the file system was using 1k or 4k block size.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 9 deletions

diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 638ce4554c76..8ada2a129d08 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -69,15 +69,8 @@ extern u8 jbd2_journal_enable_debug;
 #define jbd_debug(f, a...)	/**/
 #endif
 
-static inline void *jbd2_alloc(size_t size, gfp_t flags)
-{
-	return (void *)__get_free_pages(flags, get_order(size));
-}
-
-static inline void jbd2_free(void *ptr, size_t size)
-{
-	free_pages((unsigned long)ptr, get_order(size));
-};
+extern void *jbd2_alloc(size_t size, gfp_t flags);
+extern void jbd2_free(void *ptr, size_t size);
 
 #define JBD2_MIN_JOURNAL_BLOCKS 1024