With deployments having upwards of 600k peers now, this somewhat heavy structure could benefit from more fine-grained allocations. Specifically, instead of using a 2048-byte slab for a 1544-byte object, we can now use 1544-byte objects directly, thus saving almost 25% per-peer, or with 600k peers, that's a savings of 303 MiB. This also makes wireguard's memory usage more transparent in tools like slabtop and /proc/slabinfo.
Fixes: 8b5553ace83c ("wireguard: queueing: get rid of per-peer ring buffers") Suggested-by: Arnd Bergmann arnd@arndb.de Suggested-by: Matthew Wilcox willy@infradead.org Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com --- drivers/net/wireguard/main.c | 7 +++++++ drivers/net/wireguard/peer.c | 21 +++++++++++++++++---- drivers/net/wireguard/peer.h | 3 +++ 3 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireguard/main.c b/drivers/net/wireguard/main.c index 7a7d5f1a80fc..0a3ebfdac794 100644 --- a/drivers/net/wireguard/main.c +++ b/drivers/net/wireguard/main.c @@ -28,6 +28,10 @@ static int __init mod_init(void) #endif wg_noise_init();
+ ret = wg_peer_init(); + if (ret < 0) + goto err_peer; + ret = wg_device_init(); if (ret < 0) goto err_device; @@ -44,6 +48,8 @@ static int __init mod_init(void) err_netlink: wg_device_uninit(); err_device: + wg_peer_uninit(); +err_peer: return ret; }
@@ -51,6 +57,7 @@ static void __exit mod_exit(void) { wg_genetlink_uninit(); wg_device_uninit(); + wg_peer_uninit(); }
module_init(mod_init); diff --git a/drivers/net/wireguard/peer.c b/drivers/net/wireguard/peer.c index 3a042d28eb2e..1acd00ab2fbc 100644 --- a/drivers/net/wireguard/peer.c +++ b/drivers/net/wireguard/peer.c @@ -15,6 +15,7 @@ #include <linux/rcupdate.h> #include <linux/list.h>
+static struct kmem_cache *peer_cache; static atomic64_t peer_counter = ATOMIC64_INIT(0);
struct wg_peer *wg_peer_create(struct wg_device *wg, @@ -29,10 +30,10 @@ struct wg_peer *wg_peer_create(struct wg_device *wg, if (wg->num_peers >= MAX_PEERS_PER_DEVICE) return ERR_PTR(ret);
- peer = kzalloc(sizeof(*peer), GFP_KERNEL); + peer = kmem_cache_zalloc(peer_cache, GFP_KERNEL); if (unlikely(!peer)) return ERR_PTR(ret); - if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL)) + if (unlikely(dst_cache_init(&peer->endpoint_cache, GFP_KERNEL))) goto err;
peer->device = wg; @@ -64,7 +65,7 @@ struct wg_peer *wg_peer_create(struct wg_device *wg, return peer;
err: - kfree(peer); + kmem_cache_free(peer_cache, peer); return ERR_PTR(ret); }
@@ -193,7 +194,8 @@ static void rcu_release(struct rcu_head *rcu) /* The final zeroing takes care of clearing any remaining handshake key * material and other potentially sensitive information. */ - kfree_sensitive(peer); + memzero_explicit(peer, sizeof(*peer)); + kmem_cache_free(peer_cache, peer); }
static void kref_release(struct kref *refcount) @@ -225,3 +227,14 @@ void wg_peer_put(struct wg_peer *peer) return; kref_put(&peer->refcount, kref_release); } + +int __init wg_peer_init(void) +{ + peer_cache = KMEM_CACHE(wg_peer, 0); + return peer_cache ? 0 : -ENOMEM; +} + +void wg_peer_uninit(void) +{ + kmem_cache_destroy(peer_cache); +} diff --git a/drivers/net/wireguard/peer.h b/drivers/net/wireguard/peer.h index 8d53b687a1d1..76e4d3128ad4 100644 --- a/drivers/net/wireguard/peer.h +++ b/drivers/net/wireguard/peer.h @@ -80,4 +80,7 @@ void wg_peer_put(struct wg_peer *peer); void wg_peer_remove(struct wg_peer *peer); void wg_peer_remove_all(struct wg_device *wg);
+int wg_peer_init(void); +void wg_peer_uninit(void); + #endif /* _WG_PEER_H */