diff options
| author | Mathias Krause <minipli@googlemail.com> | 2018-05-03 10:55:07 +0200 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2018-05-04 10:14:00 +0200 |
| commit | 565f0fa902b64020d5d147ff1708567e9e0b6e49 (patch) | |
| tree | d9b201aa8f3eec09b02e5ff476f30ae658b661bd | |
| parent | 154a8c46bad2aae171fa25d5fa1d04165ef69650 (diff) | |
xfrm: use a dedicated slab cache for struct xfrm_state
struct xfrm_state is rather large (768 bytes here) and therefore wastes
quite a lot of memory as it falls into the kmalloc-1024 slab cache,
leaving 256 bytes of unused memory per XFRM state object -- a net waste
of 25%.
Using a dedicated slab cache for struct xfrm_state reduces the level of
internal fragmentation to a minimum.
On my configuration SLUB chooses to create a slab cache covering 4
pages holding 21 objects, resulting in an average memory waste of ~13
bytes per object -- a net waste of only 1.6%.
In my tests this led to memory savings of roughly 2.3MB for 10k XFRM
states.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
| -rw-r--r-- | net/xfrm/xfrm_state.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index f9d2f2233f09..f595797a20ce 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -42,6 +42,7 @@ static void xfrm_state_gc_task(struct work_struct *work); static unsigned int xfrm_state_hashmax __read_mostly = 1 * 1024 * 1024; static __read_mostly seqcount_t xfrm_state_hash_generation = SEQCNT_ZERO(xfrm_state_hash_generation); +static struct kmem_cache *xfrm_state_cache __ro_after_init; static DECLARE_WORK(xfrm_state_gc_work, xfrm_state_gc_task); static HLIST_HEAD(xfrm_state_gc_list); @@ -451,7 +452,7 @@ static void xfrm_state_gc_destroy(struct xfrm_state *x) } xfrm_dev_state_free(x); security_xfrm_state_free(x); - kfree(x); + kmem_cache_free(xfrm_state_cache, x); } static void xfrm_state_gc_task(struct work_struct *work) @@ -563,7 +564,7 @@ struct xfrm_state *xfrm_state_alloc(struct net *net) { struct xfrm_state *x; - x = kzalloc(sizeof(struct xfrm_state), GFP_ATOMIC); + x = kmem_cache_alloc(xfrm_state_cache, GFP_ATOMIC | __GFP_ZERO); if (x) { write_pnet(&x->xs_net, net); @@ -2307,6 +2308,10 @@ int __net_init xfrm_state_init(struct net *net) { unsigned int sz; + if (net_eq(net, &init_net)) + xfrm_state_cache = KMEM_CACHE(xfrm_state, + SLAB_HWCACHE_ALIGN | SLAB_PANIC); + INIT_LIST_HEAD(&net->xfrm.state_all); sz = sizeof(struct hlist_head) * 8; |