[NET]: Size listen hash tables using backlog hint
We currently allocate a fixed size (TCP_SYNQ_HSIZE=512) slots hash table for
each LISTEN socket, regardless of various parameters (listen backlog for
example)
On x86_64, this means order-1 allocations (might fail), even for 'small'
sockets, expecting few connections. On the contrary, a huge server wanting a
backlog of 50000 is slowed down a bit because of this fixed limit.
This patch makes the sizing of listen hash table a dynamic parameter,
depending of :
- net.core.somaxconn tunable (default is 128)
- net.ipv4.tcp_max_syn_backlog tunable (default : 256, 1024 or 128)
- backlog value given by user application (2nd parameter of listen())
For large allocations (bigger than PAGE_SIZE), we use vmalloc() instead of
kmalloc().
We still limit memory allocation with the two existing tunables (somaxconn &
tcp_max_syn_backlog). So for standard setups, this patch actually reduce RAM
usage.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index f743a94..b5b023e 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -28,8 +28,8 @@
struct request_sock_ops {
int family;
- kmem_cache_t *slab;
int obj_size;
+ kmem_cache_t *slab;
int (*rtx_syn_ack)(struct sock *sk,
struct request_sock *req,
struct dst_entry *dst);
@@ -51,13 +51,13 @@
u32 rcv_wnd; /* rcv_wnd offered first time */
u32 ts_recent;
unsigned long expires;
- struct request_sock_ops *rsk_ops;
+ const struct request_sock_ops *rsk_ops;
struct sock *sk;
u32 secid;
u32 peer_secid;
};
-static inline struct request_sock *reqsk_alloc(struct request_sock_ops *ops)
+static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
{
struct request_sock *req = kmem_cache_alloc(ops->slab, SLAB_ATOMIC);
@@ -121,7 +121,7 @@
};
extern int reqsk_queue_alloc(struct request_sock_queue *queue,
- const int nr_table_entries);
+ unsigned int nr_table_entries);
static inline struct listen_sock *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue)
{