Since SLOB was removed and since commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), it is not necessary to use call_rcu when the callback only performs kmem_cache_free. Use kfree_rcu() directly.

The changes were made using Coccinelle.

Signed-off-by: Julia Lawall Julia.Lawall@inria.fr

--- net/batman-adv/translation-table.c | 47 ++----------------------------------- 1 file changed, 3 insertions(+), 44 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 2243cec18ecc..b21ff3c36b07 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -208,20 +208,6 @@ batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr, return tt_global_entry; }

-/** - * batadv_tt_local_entry_free_rcu() - free the tt_local_entry - * @rcu: rcu pointer of the tt_local_entry - */ -static void batadv_tt_local_entry_free_rcu(struct rcu_head *rcu) -{ - struct batadv_tt_local_entry *tt_local_entry; - - tt_local_entry = container_of(rcu, struct batadv_tt_local_entry, - common.rcu); - - kmem_cache_free(batadv_tl_cache, tt_local_entry); -} - /** * batadv_tt_local_entry_release() - release tt_local_entry from lists and queue * for free after rcu grace period @@ -236,7 +222,7 @@ static void batadv_tt_local_entry_release(struct kref *ref)

batadv_softif_vlan_put(tt_local_entry->vlan);

- call_rcu(&tt_local_entry->common.rcu, batadv_tt_local_entry_free_rcu); + kfree_rcu(tt_local_entry, common.rcu); }

/** @@ -254,20 +240,6 @@ batadv_tt_local_entry_put(struct batadv_tt_local_entry *tt_local_entry) batadv_tt_local_entry_release); }

-/** - * batadv_tt_global_entry_free_rcu() - free the tt_global_entry - * @rcu: rcu pointer of the tt_global_entry - */ -static void batadv_tt_global_entry_free_rcu(struct rcu_head *rcu) -{ - struct batadv_tt_global_entry *tt_global_entry; - - tt_global_entry = container_of(rcu, struct batadv_tt_global_entry, - common.rcu); - - kmem_cache_free(batadv_tg_cache, tt_global_entry); -} - /** * batadv_tt_global_entry_release() - release tt_global_entry from lists and * queue for free after rcu grace period @@ -282,7 +254,7 @@ void batadv_tt_global_entry_release(struct kref *ref)

batadv_tt_global_del_orig_list(tt_global_entry);

- call_rcu(&tt_global_entry->common.rcu, batadv_tt_global_entry_free_rcu); + kfree_rcu(tt_global_entry, common.rcu); }

/** @@ -407,19 +379,6 @@ static void batadv_tt_global_size_dec(struct batadv_orig_node *orig_node, batadv_tt_global_size_mod(orig_node, vid, -1); }

-/** - * batadv_tt_orig_list_entry_free_rcu() - free the orig_entry - * @rcu: rcu pointer of the orig_entry - */ -static void batadv_tt_orig_list_entry_free_rcu(struct rcu_head *rcu) -{ - struct batadv_tt_orig_list_entry *orig_entry; - - orig_entry = container_of(rcu, struct batadv_tt_orig_list_entry, rcu); - - kmem_cache_free(batadv_tt_orig_cache, orig_entry); -} - /** * batadv_tt_orig_list_entry_release() - release tt orig entry from lists and * queue for free after rcu grace period @@ -433,7 +392,7 @@ static void batadv_tt_orig_list_entry_release(struct kref *ref) refcount);

batadv_orig_node_put(orig_entry->orig_node); - call_rcu(&orig_entry->rcu, batadv_tt_orig_list_entry_free_rcu); + kfree_rcu(orig_entry, rcu); }

/**

On Sun, Oct 13, 2024 at 10:16:47PM +0200, Julia Lawall wrote:

Since SLOB was removed and since commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), it is not necessary to use call_rcu when the callback only performs kmem_cache_free. Use kfree_rcu() directly.

The changes were done using the following Coccinelle semantic patch. This semantic patch is designed to ignore cases where the callback function is used in another way.

For the series:

Acked-by: Paul E. McKenney paulmck@kernel.org

// <smpl> #spatch --all-includes --include-headers

@r@ expression e; local idexpression e2; identifier cb,f,g; position p; @@

( call_rcu(...,e2) | call_rcu(&e->f,cb@p) | call_rcu(&e->f.g,cb@p) )

@r1@ type T,T1; identifier x,r.cb; @@

cb(...) { ( kmem_cache_free(...); | T x = ...; kmem_cache_free(...,(T1)x); | T x; x = ...; kmem_cache_free(...,(T1)x); ) }

@s depends on r1@ position p != r.p; identifier r.cb; @@

cb@p

@script:ocaml@ cb << r.cb; p << s.p; @@

Printf.eprintf "Other use of %s at %s:%d\n" cb (List.hd p).file (List.hd p).line

@depends on r1 && !s@ expression e; identifier r.cb,f,g; position r.p; @@

(

• call_rcu(&e->f,cb@p)

• kfree_rcu(e,f)

|

• call_rcu(&e->f.g,cb@p)

• kfree_rcu(e,f.g)

)

@r1a depends on !s@ type T,T1; identifier x,r.cb; @@

• cb(...) {

(

• kmem_cache_free(...);

|

• T x = ...;
• kmem_cache_free(...,(T1)x);

|

• T x;
• x = ...;
• kmem_cache_free(...,(T1)x);

)

• }

@r2 depends on !r1@ identifier r.cb; @@

cb(...) { ... }

@script:ocaml depends on !r1 && !r2@ cb << r.cb; @@

Printf.eprintf "need definition for %s\n" cb // </smpl>

---

arch/powerpc/kvm/book3s_mmu_hpte.c | 8 ------ block/blk-ioc.c | 9 ------ drivers/net/wireguard/allowedips.c | 9 +----- fs/ecryptfs/dentry.c | 8 ------ fs/nfsd/nfs4state.c | 9 ------ kernel/time/posix-timers.c | 9 ------ net/batman-adv/translation-table.c | 47 ++---------------------------------- net/bridge/br_fdb.c | 9 ------ net/can/gw.c | 13 ++------- net/ipv4/fib_trie.c | 8 ------ net/ipv4/inetpeer.c | 9 +----- net/ipv6/ip6_fib.c | 9 ------ net/ipv6/xfrm6_tunnel.c | 8 ------ net/kcm/kcmsock.c | 10 ------- net/netfilter/nf_conncount.c | 10 ------- net/netfilter/nf_conntrack_expect.c | 10 ------- net/netfilter/xt_hashlimit.c | 9 ------ 17 files changed, 23 insertions(+), 171 deletions(-)