On Thu, August 08, 2013 at 07:04 (+0200), Wang Shilong wrote: > struct __prelim_ref is allocated and freed frequently when > walking backref tree, using slab allocater can not only > speed up allocating but also detect memory leaks. > > Signed-off-by: Wang Shilong <wangsl.f...@cn.fujitsu.com> > Reviewed-by: Miao Xie <mi...@cn.fujitsu.com> > --- > fs/btrfs/backref.c | 30 +++++++++++++++++++++++++----- > fs/btrfs/backref.h | 2 ++ > fs/btrfs/super.c | 8 ++++++++ > 3 files changed, 35 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c > index f7781e6..916e4f1 100644 > --- a/fs/btrfs/backref.c > +++ b/fs/btrfs/backref.c > @@ -119,6 +119,26 @@ struct __prelim_ref { > u64 wanted_disk_byte; > }; > > +static struct kmem_cache *prelim_ref_cache; > + > +int __init btrfs_prelim_ref_init(void) > +{ > + prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", > + sizeof(struct __prelim_ref), > + 0, > + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, > + NULL); > + if (!prelim_ref_cache) > + return -ENOMEM; > + return 0; > +} > + > +void btrfs_prelim_ref_exit(void) > +{ > + if (prelim_ref_cache) > + kmem_cache_destroy(prelim_ref_cache); > +} > + > /* > * the rules for all callers of this function are: > * - obtaining the parent is the goal > @@ -165,7 +185,7 @@ static int __add_prelim_ref(struct list_head *head, u64 > root_id, > { > struct __prelim_ref *ref; > > - ref = kmalloc(sizeof(*ref), gfp_mask); > + ref = kmem_cache_alloc(prelim_ref_cache, gfp_mask); > if (!ref) > return -ENOMEM; > > @@ -493,7 +513,7 @@ static void __merge_refs(struct list_head *head, int mode) > ref1->count += ref2->count; > > list_del(&ref2->list); > - kfree(ref2); > + kmem_cache_free(prelim_ref_cache, ref2); > } > > } > @@ -958,7 +978,7 @@ again: > } > } > list_del(&ref->list); > - kfree(ref); > + kmem_cache_free(prelim_ref_cache, ref); > } > > out: > @@ -966,13 +986,13 @@ out: > while (!list_empty(&prefs)) { > ref = list_first_entry(&prefs, struct __prelim_ref, list); > list_del(&ref->list); > - kfree(ref); > + kmem_cache_free(prelim_ref_cache, ref); > } > while (!list_empty(&prefs_delayed)) { > ref = list_first_entry(&prefs_delayed, struct __prelim_ref, > list); > list_del(&ref->list); > - kfree(ref); > + kmem_cache_free(prelim_ref_cache, ref); > } > > return ret; > diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h > index 8f2e767..a910b27 100644 > --- a/fs/btrfs/backref.h > +++ b/fs/btrfs/backref.h > @@ -72,4 +72,6 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 > inode_objectid, > struct btrfs_inode_extref **ret_extref, > u64 *found_off); > > +int __init btrfs_prelim_ref_init(void); > +void btrfs_prelim_ref_exit(void); > #endif > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index b64d762..de7eb3d 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -56,6 +56,7 @@ > #include "rcu-string.h" > #include "dev-replace.h" > #include "free-space-cache.h" > +#include "backref.h" > > #define CREATE_TRACE_POINTS > #include <trace/events/btrfs.h> > @@ -1774,6 +1775,10 @@ static int __init init_btrfs_fs(void) > if (err) > goto free_auto_defrag; > > + err = btrfs_prelim_ref_init(); > + if (err) > + goto free_prelim_ref; > + > err = btrfs_interface_init(); > if (err) > goto free_delayed_ref; > @@ -1791,6 +1796,8 @@ static int __init init_btrfs_fs(void) > > unregister_ioctl: > btrfs_interface_exit(); > +free_prelim_ref: > + btrfs_prelim_ref_exit(); > free_delayed_ref: > btrfs_delayed_ref_exit(); > free_auto_defrag: > @@ -1817,6 +1824,7 @@ static void __exit exit_btrfs_fs(void) > btrfs_delayed_ref_exit(); > btrfs_auto_defrag_exit(); > btrfs_delayed_inode_exit(); > + btrfs_prelim_ref_exit(); > ordered_data_exit(); > extent_map_exit(); > extent_io_exit(); >
I generally like the idea of using a custom cache here. What about this one? 324 static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, [...] 367 /* additional parents require new refs being added here */ 368 while ((node = ulist_next(parents, &uiter))) { 369 new_ref = kmalloc(sizeof(*new_ref), GFP_NOFS); That new_ref will also be freed with kmem_cache_free after your patch, I think. Thanks, -Jan -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html