Since SLOB was removed, 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. // <smpl> @r@ expression e; local idexpression e2; identifier cb,f; position p; @@ ( call_rcu(...,e2) | call_rcu(&e->f,cb@p) ) @r1@ type T; identifier x,r.cb; @@ cb(...) { ( kmem_cache_free(...); | T x = ...; kmem_cache_free(...,x); | T x; x = ...; kmem_cache_free(...,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; position r.p; @@ - call_rcu(&e->f,cb@p) + kfree_rcu(e,f) @r1a depends on !s@ type T; identifier x,r.cb; @@ - cb(...) { ( - kmem_cache_free(...); | - T x = ...; - kmem_cache_free(...,x); | - T x; - x = ...; - kmem_cache_free(...,x); ) - } // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx> Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> --- net/kcm/kcmsock.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index 2f191e50d4fc..fbb730cd2d38 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1580,14 +1580,6 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) return err; } -static void free_mux(struct rcu_head *rcu) -{ - struct kcm_mux *mux = container_of(rcu, - struct kcm_mux, rcu); - - kmem_cache_free(kcm_muxp, mux); -} - static void release_mux(struct kcm_mux *mux) { struct kcm_net *knet = mux->knet; @@ -1615,7 +1607,7 @@ static void release_mux(struct kcm_mux *mux) knet->count--; mutex_unlock(&knet->mutex); - call_rcu(&mux->rcu, free_mux); + kfree_rcu(mux, rcu); } static void kcm_done(struct kcm_sock *kcm)