target/linux/generic/backport-5.4/080-wireguard-0131-wireguard-peer-allocate-in-kmem_cache.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
   3 Date: Fri, 4 Jun 2021 17:17:34 +0200
   4 Subject: [PATCH] wireguard: peer: allocate in kmem_cache
   5
   6 commit a4e9f8e3287c9eb6bf70df982870980dd3341863 upstream.
   7
   8 With deployments having upwards of 600k peers now, this somewhat heavy
   9 structure could benefit from more fine-grained allocations.
  10 Specifically, instead of using a 2048-byte slab for a 1544-byte object,
  11 we can now use 1544-byte objects directly, thus saving almost 25%
  12 per-peer, or with 600k peers, that's a savings of 303 MiB. This also
  13 makes wireguard's memory usage more transparent in tools like slabtop
  14 and /proc/slabinfo.
  15
  16 Fixes: 8b5553ace83c ("wireguard: queueing: get rid of per-peer ring buffers")
  17 Suggested-by: Arnd Bergmann <arnd@arndb.de>
  18 Suggested-by: Matthew Wilcox <willy@infradead.org>
  19 Cc: stable@vger.kernel.org
  20 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  21 Signed-off-by: David S. Miller <davem@davemloft.net>
  22 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  23 ---
  24  drivers/net/wireguard/main.c |  7 +++++++
  25  drivers/net/wireguard/peer.c | 21 +++++++++++++++++----
  26  drivers/net/wireguard/peer.h |  3 +++
  27  3 files changed, 27 insertions(+), 4 deletions(-)
  28
  29 --- a/drivers/net/wireguard/main.c
  30 +++ b/drivers/net/wireguard/main.c
  31 @@ -28,6 +28,10 @@ static int __init mod_init(void)
  32  #endif
  33         wg_noise_init();
  34
  35 +       ret = wg_peer_init();
  36 +       if (ret < 0)
  37 +               goto err_peer;
  38 +
  39         ret = wg_device_init();
  40         if (ret < 0)
  41                 goto err_device;
  42 @@ -44,6 +48,8 @@ static int __init mod_init(void)
  43  err_netlink:
  44         wg_device_uninit();
  45  err_device:
  46 +       wg_peer_uninit();
  47 +err_peer:
  48         return ret;
  49  }
  50
  51 @@ -51,6 +57,7 @@ static void __exit mod_exit(void)
  52  {
  53         wg_genetlink_uninit();
  54         wg_device_uninit();
  55 +       wg_peer_uninit();
  56  }
  57
  58  module_init(mod_init);
  59 --- a/drivers/net/wireguard/peer.c
  60 +++ b/drivers/net/wireguard/peer.c
  61 @@ -15,6 +15,7 @@
  62  #include <linux/rcupdate.h>
  63  #include <linux/list.h>
  64
  65 +static struct kmem_cache *peer_cache;
  66  static atomic64_t peer_counter = ATOMIC64_INIT(0);
  67
  68  struct wg_peer *wg_peer_create(struct wg_device *wg,
  69 @@ -29,10 +30,10 @@ struct wg_peer *wg_peer_create(struct wg
  70         if (wg->num_peers >= MAX_PEERS_PER_DEVICE)
  71                 return ERR_PTR(ret);
  72
  73 -       peer = kzalloc(sizeof(*peer), GFP_KERNEL);
  74 +       peer = kmem_cache_zalloc(peer_cache, GFP_KERNEL);
  75         if (unlikely(!peer))
  76                 return ERR_PTR(ret);
  77 -       if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL))
  78 +       if (unlikely(dst_cache_init(&peer->endpoint_cache, GFP_KERNEL)))
  79                 goto err;
  80
  81         peer->device = wg;
  82 @@ -64,7 +65,7 @@ struct wg_peer *wg_peer_create(struct wg
  83         return peer;
  84
  85  err:
  86 -       kfree(peer);
  87 +       kmem_cache_free(peer_cache, peer);
  88         return ERR_PTR(ret);
  89  }
  90
  91 @@ -193,7 +194,8 @@ static void rcu_release(struct rcu_head
  92         /* The final zeroing takes care of clearing any remaining handshake key
  93          * material and other potentially sensitive information.
  94          */
  95 -       kzfree(peer);
  96 +       memzero_explicit(peer, sizeof(*peer));
  97 +       kmem_cache_free(peer_cache, peer);
  98  }
  99
 100  static void kref_release(struct kref *refcount)
 101 @@ -225,3 +227,14 @@ void wg_peer_put(struct wg_peer *peer)
 102                 return;
 103         kref_put(&peer->refcount, kref_release);
 104  }
 105 +
 106 +int __init wg_peer_init(void)
 107 +{
 108 +       peer_cache = KMEM_CACHE(wg_peer, 0);
 109 +       return peer_cache ? 0 : -ENOMEM;
 110 +}
 111 +
 112 +void wg_peer_uninit(void)
 113 +{
 114 +       kmem_cache_destroy(peer_cache);
 115 +}
 116 --- a/drivers/net/wireguard/peer.h
 117 +++ b/drivers/net/wireguard/peer.h
 118 @@ -80,4 +80,7 @@ void wg_peer_put(struct wg_peer *peer);
 119  void wg_peer_remove(struct wg_peer *peer);
 120  void wg_peer_remove_all(struct wg_device *wg);
 121
 122 +int wg_peer_init(void);
 123 +void wg_peer_uninit(void);
 124 +
 125  #endif /* _WG_PEER_H */