This is a note to let you know that I've just added the patch titled wireguard: peer: allocate in kmem_cache to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wireguard-peer-allocate-in-kmem_cache.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a4e9f8e3287c9eb6bf70df982870980dd3341863 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Date: Fri, 4 Jun 2021 17:17:34 +0200 Subject: wireguard: peer: allocate in kmem_cache From: Jason A. Donenfeld <Jason@xxxxxxxxx> 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 <arnd@xxxxxxxx> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 <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 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. */ - 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); +} --- 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 */ Patches currently in stable-queue which might be from Jason@xxxxxxxxx are queue-5.10/wireguard-use-synchronize_net-rather-than-synchronize_rcu.patch queue-5.10/wireguard-do-not-use-o3.patch queue-5.10/wireguard-allowedips-allocate-nodes-in-kmem_cache.patch queue-5.10/wireguard-allowedips-initialize-list-head-in-selftest.patch queue-5.10/wireguard-selftests-remove-old-conntrack-kconfig-value.patch queue-5.10/wireguard-peer-allocate-in-kmem_cache.patch queue-5.10/wireguard-allowedips-remove-nodes-in-o-1.patch queue-5.10/wireguard-selftests-make-sure-rp_filter-is-disabled-on-vethc.patch queue-5.10/wireguard-allowedips-free-empty-intermediate-nodes-when-removing-single-node.patch