Commit a4e9f8e3 authored by Jason A. Donenfeld's avatar Jason A. Donenfeld Committed by David S. Miller
Browse files

wireguard: peer: allocate in kmem_cache 



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: 8b5553ac ("wireguard: queueing: get rid of per-peer ring buffers")
Suggested-by: default avatarArnd Bergmann <arnd@arndb.de>
Suggested-by: default avatarMatthew Wilcox <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 24b70eee

drivers/net/wireguard/main.c

+7 −0
Original line number Diff line number Diff line
@@ -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);

drivers/net/wireguard/peer.c

+17 −4
Original line number Diff line number Diff line
@@ -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);

}

drivers/net/wireguard/peer.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */