| Message ID | 20240609082726.32742-9-Julia.Lawall@inria.fr (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | replace call_rcu by kfree_rcu for simple kmem_cache_free callback | expand |
On Sun, 2024-06-09 at 10:27 +0200, Julia Lawall wrote: > 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@inria.fr> > Reviewed-by: Paul E. McKenney <paulmck@kernel.org> > Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > > --- > fs/nfsd/nfs4state.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index a20c2c9d7d45..eba5083504c7 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -571,13 +571,6 @@ opaque_hashval(const void *ptr, int nbytes) > return x; > } > > -static void nfsd4_free_file_rcu(struct rcu_head *rcu) > -{ > - struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu); > - > - kmem_cache_free(file_slab, fp); > -} > - > void > put_nfs4_file(struct nfs4_file *fi) > { > @@ -585,7 +578,7 @@ put_nfs4_file(struct nfs4_file *fi) > nfsd4_file_hash_remove(fi); > WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate)); > WARN_ON_ONCE(!list_empty(&fi->fi_delegations)); > - call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu); > + kfree_rcu(fi, fi_rcu); > } > } > > Reviewed-by: Jeff Layton <jlayton@kernel.org>
On Sun, Jun 09, 2024 at 10:27:20AM +0200, Julia Lawall wrote: > 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@inria.fr> > Reviewed-by: Paul E. McKenney <paulmck@kernel.org> > Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > > --- > fs/nfsd/nfs4state.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index a20c2c9d7d45..eba5083504c7 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -571,13 +571,6 @@ opaque_hashval(const void *ptr, int nbytes) > return x; > } > > -static void nfsd4_free_file_rcu(struct rcu_head *rcu) > -{ > - struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu); > - > - kmem_cache_free(file_slab, fp); > -} > - > void > put_nfs4_file(struct nfs4_file *fi) > { > @@ -585,7 +578,7 @@ put_nfs4_file(struct nfs4_file *fi) > nfsd4_file_hash_remove(fi); > WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate)); > WARN_ON_ONCE(!list_empty(&fi->fi_delegations)); > - call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu); > + kfree_rcu(fi, fi_rcu); > } > } > > Acked-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a20c2c9d7d45..eba5083504c7 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -571,13 +571,6 @@ opaque_hashval(const void *ptr, int nbytes) return x; } -static void nfsd4_free_file_rcu(struct rcu_head *rcu) -{ - struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu); - - kmem_cache_free(file_slab, fp); -} - void put_nfs4_file(struct nfs4_file *fi) { @@ -585,7 +578,7 @@ put_nfs4_file(struct nfs4_file *fi) nfsd4_file_hash_remove(fi); WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate)); WARN_ON_ONCE(!list_empty(&fi->fi_delegations)); - call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu); + kfree_rcu(fi, fi_rcu); } }
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@inria.fr> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> --- fs/nfsd/nfs4state.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-)