| Message ID | 20230622085335.77010-16-zhengqi.arch@bytedance.com |
|---|---|
| State | New |
| Headers | show |
| Series | use refcount+RCU method to implement lockless slab shrink | expand |
On Thu, Jun 22, 2023 at 04:53:21PM +0800, Qi Zheng wrote: > In preparation for implementing lockless slab shrink, > we need to dynamically allocate the nfsd-client shrinker, > so that it can be freed asynchronously using kfree_rcu(). > Then it doesn't need to wait for RCU read-side critical > section when releasing the struct nfsd_net. > > Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> For 15/29 and 16/29 of this series: Acked-by: Chuck Lever <chuck.lever@oracle.com> > --- > fs/nfsd/netns.h | 2 +- > fs/nfsd/nfs4state.c | 20 ++++++++++++-------- > 2 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h > index ec49b200b797..f669444d5336 100644 > --- a/fs/nfsd/netns.h > +++ b/fs/nfsd/netns.h > @@ -195,7 +195,7 @@ struct nfsd_net { > int nfs4_max_clients; > > atomic_t nfsd_courtesy_clients; > - struct shrinker nfsd_client_shrinker; > + struct shrinker *nfsd_client_shrinker; > struct work_struct nfsd_shrinker_work; > }; > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index 6e61fa3acaf1..a06184270548 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -4388,8 +4388,7 @@ static unsigned long > nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc) > { > int count; > - struct nfsd_net *nn = container_of(shrink, > - struct nfsd_net, nfsd_client_shrinker); > + struct nfsd_net *nn = shrink->private_data; > > count = atomic_read(&nn->nfsd_courtesy_clients); > if (!count) > @@ -8094,14 +8093,19 @@ static int nfs4_state_create_net(struct net *net) > INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker); > get_net(net); > > - nn->nfsd_client_shrinker.scan_objects = nfsd4_state_shrinker_scan; > - nn->nfsd_client_shrinker.count_objects = nfsd4_state_shrinker_count; > - nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS; > - > - if (register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client")) > + nn->nfsd_client_shrinker = shrinker_alloc_and_init(nfsd4_state_shrinker_count, > + nfsd4_state_shrinker_scan, > + 0, DEFAULT_SEEKS, 0, > + nn); > + if (!nn->nfsd_client_shrinker) > goto err_shrinker; > + > + if (register_shrinker(nn->nfsd_client_shrinker, "nfsd-client")) > + goto err_register; > return 0; > > +err_register: > + shrinker_free(nn->nfsd_client_shrinker); > err_shrinker: > put_net(net); > kfree(nn->sessionid_hashtbl); > @@ -8197,7 +8201,7 @@ nfs4_state_shutdown_net(struct net *net) > struct list_head *pos, *next, reaplist; > struct nfsd_net *nn = net_generic(net, nfsd_net_id); > > - unregister_shrinker(&nn->nfsd_client_shrinker); > + unregister_and_free_shrinker(nn->nfsd_client_shrinker); > cancel_work(&nn->nfsd_shrinker_work); > cancel_delayed_work_sync(&nn->laundromat_work); > locks_end_grace(&nn->nfsd4_manager); > -- > 2.30.2 >
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index ec49b200b797..f669444d5336 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -195,7 +195,7 @@ struct nfsd_net { int nfs4_max_clients; atomic_t nfsd_courtesy_clients; - struct shrinker nfsd_client_shrinker; + struct shrinker *nfsd_client_shrinker; struct work_struct nfsd_shrinker_work; }; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 6e61fa3acaf1..a06184270548 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4388,8 +4388,7 @@ static unsigned long nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc) { int count; - struct nfsd_net *nn = container_of(shrink, - struct nfsd_net, nfsd_client_shrinker); + struct nfsd_net *nn = shrink->private_data; count = atomic_read(&nn->nfsd_courtesy_clients); if (!count) @@ -8094,14 +8093,19 @@ static int nfs4_state_create_net(struct net *net) INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker); get_net(net); - nn->nfsd_client_shrinker.scan_objects = nfsd4_state_shrinker_scan; - nn->nfsd_client_shrinker.count_objects = nfsd4_state_shrinker_count; - nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS; - - if (register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client")) + nn->nfsd_client_shrinker = shrinker_alloc_and_init(nfsd4_state_shrinker_count, + nfsd4_state_shrinker_scan, + 0, DEFAULT_SEEKS, 0, + nn); + if (!nn->nfsd_client_shrinker) goto err_shrinker; + + if (register_shrinker(nn->nfsd_client_shrinker, "nfsd-client")) + goto err_register; return 0; +err_register: + shrinker_free(nn->nfsd_client_shrinker); err_shrinker: put_net(net); kfree(nn->sessionid_hashtbl); @@ -8197,7 +8201,7 @@ nfs4_state_shutdown_net(struct net *net) struct list_head *pos, *next, reaplist; struct nfsd_net *nn = net_generic(net, nfsd_net_id); - unregister_shrinker(&nn->nfsd_client_shrinker); + unregister_and_free_shrinker(nn->nfsd_client_shrinker); cancel_work(&nn->nfsd_shrinker_work); cancel_delayed_work_sync(&nn->laundromat_work); locks_end_grace(&nn->nfsd4_manager);
In preparation for implementing lockless slab shrink, we need to dynamically allocate the nfsd-client shrinker, so that it can be freed asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU read-side critical section when releasing the struct nfsd_net. Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> --- fs/nfsd/netns.h | 2 +- fs/nfsd/nfs4state.c | 20 ++++++++++++-------- 2 files changed, 13 insertions(+), 9 deletions(-)