From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Fri, 4 Jun 2021 17:17:34 +0200 Subject: [PATCH] wireguard: peer: allocate in kmem_cache commit a4e9f8e3287c9eb6bf70df982870980dd3341863 upstream. 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 Suggested-by: Matthew Wilcox Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller Signed-off-by: Jason A. Donenfeld --- 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(-) --- 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); --- a/drivers/net/wireguard/peer.c +++ b/drivers/net/wireguard/peer.c @@ -15,6 +15,7 @@ #include #include +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 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 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 /* The final zeroing takes care of clearing any remaining handshake key * material and other potentially sensitive information. */ - kzfree(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); +} --- 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 */