bufferhead: revert constructor removal

The constructor for buffer_head slabs was removed recently.  We need the
constructor back in slab defrag in order to insure that slab objects always
have a definite state even before we allocated them.

I think we mistakenly merged the removal of the constuctor into a cleanup
patch.  You (ie: akpm) had a test that showed that the removal of the
constructor led to a small regression.  The prior state makes things easier
for slab defrag.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Lameter 2008-02-04 22:28:36 -08:00 committed by Linus Torvalds
parent aec2c3ed01
commit b98938c373

View File

@ -3153,7 +3153,7 @@ static void recalc_bh_state(void)
struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
{
struct buffer_head *ret = kmem_cache_zalloc(bh_cachep,
struct buffer_head *ret = kmem_cache_alloc(bh_cachep,
set_migrateflags(gfp_flags, __GFP_RECLAIMABLE));
if (ret) {
INIT_LIST_HEAD(&ret->b_assoc_buffers);
@ -3241,12 +3241,24 @@ int bh_submit_read(struct buffer_head *bh)
}
EXPORT_SYMBOL(bh_submit_read);
static void
init_buffer_head(struct kmem_cache *cachep, void *data)
{
struct buffer_head *bh = data;
memset(bh, 0, sizeof(*bh));
INIT_LIST_HEAD(&bh->b_assoc_buffers);
}
void __init buffer_init(void)
{
int nrpages;
bh_cachep = KMEM_CACHE(buffer_head,
SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD);
bh_cachep = kmem_cache_create("buffer_head",
sizeof(struct buffer_head), 0,
(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
SLAB_MEM_SPREAD),
init_buffer_head);
/*
* Limit the bh occupancy to 10% of ZONE_NORMAL