net: add per_cpu_fw_alloc field to struct proto

Each protocol having a ->memory_allocated pointer gets a corresponding
per-cpu reserve, that following patches will use.

Instead of having reserved bytes per socket,
we want to have per-cpu reserves.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/sock.h

@@ -1254,6 +1254,7 @@ struct proto {
 	void			(*enter_memory_pressure)(struct sock *sk);
 	void			(*leave_memory_pressure)(struct sock *sk);
 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
+	int  __percpu		*per_cpu_fw_alloc;
 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
 
 	/*

include/net/tcp.h

@@ -253,6 +253,8 @@ extern long sysctl_tcp_mem[3];
 #define TCP_RACK_NO_DUPTHRESH    0x4 /* Do not use DUPACK threshold in RACK */
 
 extern atomic_long_t tcp_memory_allocated;
+DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
+
 extern struct percpu_counter tcp_sockets_allocated;
 extern unsigned long tcp_memory_pressure;
 

include/net/udp.h

@@ -95,6 +95,7 @@ static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
 extern struct proto udp_prot;
 
 extern atomic_long_t udp_memory_allocated;
+DECLARE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
 
 /* sysctl variables for udp */
 extern long sysctl_udp_mem[3];

net/core/sock.c

@@ -3798,6 +3798,10 @@ int proto_register(struct proto *prot, int alloc_slab)
 		pr_err("%s: missing sysctl_mem\n", prot->name);
 		return -EINVAL;
 	}
+	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
+		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
+		return -EINVAL;
+	}
 	if (alloc_slab) {
 		prot->slab = kmem_cache_create_usercopy(prot->name,
 					prot->obj_size, 0,

net/decnet/af_decnet.c

@@ -149,6 +149,7 @@ static DEFINE_RWLOCK(dn_hash_lock);
 static struct hlist_head dn_sk_hash[DN_SK_HASH_SIZE];
 static struct hlist_head dn_wild_sk;
 static atomic_long_t decnet_memory_allocated;
+static DEFINE_PER_CPU(int, decnet_memory_per_cpu_fw_alloc);
 
 static int __dn_setsockopt(struct socket *sock, int level, int optname,
 		sockptr_t optval, unsigned int optlen, int flags);
@@ -454,7 +455,10 @@ static struct proto dn_proto = {
 	.owner			= THIS_MODULE,
 	.enter_memory_pressure	= dn_enter_memory_pressure,
 	.memory_pressure	= &dn_memory_pressure,
+
 	.memory_allocated	= &decnet_memory_allocated,
+	.per_cpu_fw_alloc	= &decnet_memory_per_cpu_fw_alloc,
+
 	.sysctl_mem		= sysctl_decnet_mem,
 	.sysctl_wmem		= sysctl_decnet_wmem,
 	.sysctl_rmem		= sysctl_decnet_rmem,

net/ipv4/tcp.c

@@ -294,6 +294,8 @@ EXPORT_SYMBOL(sysctl_tcp_mem);
 
 atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp;	/* Current allocated memory. */
 EXPORT_SYMBOL(tcp_memory_allocated);
+DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
+EXPORT_PER_CPU_SYMBOL_GPL(tcp_memory_per_cpu_fw_alloc);
 
 #if IS_ENABLED(CONFIG_SMC)
 DEFINE_STATIC_KEY_FALSE(tcp_have_smc);

net/ipv4/tcp_ipv4.c

@@ -3045,7 +3045,10 @@ struct proto tcp_prot = {
 	.stream_memory_free	= tcp_stream_memory_free,
 	.sockets_allocated	= &tcp_sockets_allocated,
 	.orphan_count		= &tcp_orphan_count,
+
 	.memory_allocated	= &tcp_memory_allocated,
+	.per_cpu_fw_alloc	= &tcp_memory_per_cpu_fw_alloc,
+
 	.memory_pressure	= &tcp_memory_pressure,
 	.sysctl_mem		= sysctl_tcp_mem,
 	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_wmem),

net/ipv4/udp.c

@@ -125,6 +125,8 @@ EXPORT_SYMBOL(sysctl_udp_mem);
 
 atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
 EXPORT_SYMBOL(udp_memory_allocated);
+DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
+EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
 
 #define MAX_UDP_PORTS 65536
 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
@@ -2946,6 +2948,8 @@ struct proto udp_prot = {
 	.psock_update_sk_prot	= udp_bpf_update_proto,
 #endif
 	.memory_allocated	= &udp_memory_allocated,
+	.per_cpu_fw_alloc	= &udp_memory_per_cpu_fw_alloc,
+
 	.sysctl_mem		= sysctl_udp_mem,
 	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_udp_wmem_min),
 	.sysctl_rmem_offset	= offsetof(struct net, ipv4.sysctl_udp_rmem_min),

net/ipv4/udplite.c

@@ -51,7 +51,10 @@ struct proto 	udplite_prot = {
 	.unhash		   = udp_lib_unhash,
 	.rehash		   = udp_v4_rehash,
 	.get_port	   = udp_v4_get_port,
+
 	.memory_allocated  = &udp_memory_allocated,
+	.per_cpu_fw_alloc  = &udp_memory_per_cpu_fw_alloc,
+
 	.sysctl_mem	   = sysctl_udp_mem,
 	.obj_size	   = sizeof(struct udp_sock),
 	.h.udp_table	   = &udplite_table,

net/ipv6/tcp_ipv6.c

@@ -2159,7 +2159,10 @@ struct proto tcpv6_prot = {
 	.leave_memory_pressure	= tcp_leave_memory_pressure,
 	.stream_memory_free	= tcp_stream_memory_free,
 	.sockets_allocated	= &tcp_sockets_allocated,
+
 	.memory_allocated	= &tcp_memory_allocated,
+	.per_cpu_fw_alloc	= &tcp_memory_per_cpu_fw_alloc,
+
 	.memory_pressure	= &tcp_memory_pressure,
 	.orphan_count		= &tcp_orphan_count,
 	.sysctl_mem		= sysctl_tcp_mem,

net/ipv6/udp.c

@@ -1740,7 +1740,10 @@ struct proto udpv6_prot = {
 #ifdef CONFIG_BPF_SYSCALL
 	.psock_update_sk_prot	= udp_bpf_update_proto,
 #endif
+
 	.memory_allocated	= &udp_memory_allocated,
+	.per_cpu_fw_alloc	= &udp_memory_per_cpu_fw_alloc,
+
 	.sysctl_mem		= sysctl_udp_mem,
 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),

net/ipv6/udplite.c

@@ -48,7 +48,10 @@ struct proto udplitev6_prot = {
 	.unhash		   = udp_lib_unhash,
 	.rehash		   = udp_v6_rehash,
 	.get_port	   = udp_v6_get_port,
+
 	.memory_allocated  = &udp_memory_allocated,
+	.per_cpu_fw_alloc  = &udp_memory_per_cpu_fw_alloc,
+
 	.sysctl_mem	   = sysctl_udp_mem,
 	.obj_size	   = sizeof(struct udp6_sock),
 	.h.udp_table	   = &udplite_table,

net/mptcp/protocol.c

@@ -3437,7 +3437,10 @@ static struct proto mptcp_prot = {
 	.get_port	= mptcp_get_port,
 	.forward_alloc_get	= mptcp_forward_alloc_get,
 	.sockets_allocated	= &mptcp_sockets_allocated,
+
 	.memory_allocated	= &tcp_memory_allocated,
+	.per_cpu_fw_alloc	= &tcp_memory_per_cpu_fw_alloc,
+
 	.memory_pressure	= &tcp_memory_pressure,
 	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_wmem),
 	.sysctl_rmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_rmem),

net/sctp/socket.c

@@ -93,6 +93,7 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 
 static unsigned long sctp_memory_pressure;
 static atomic_long_t sctp_memory_allocated;
+static DEFINE_PER_CPU(int, sctp_memory_per_cpu_fw_alloc);
 struct percpu_counter sctp_sockets_allocated;
 
 static void sctp_enter_memory_pressure(struct sock *sk)
@@ -9657,7 +9658,10 @@ struct proto sctp_prot = {
 	.sysctl_wmem =  sysctl_sctp_wmem,
 	.memory_pressure = &sctp_memory_pressure,
 	.enter_memory_pressure = sctp_enter_memory_pressure,
+
 	.memory_allocated = &sctp_memory_allocated,
+	.per_cpu_fw_alloc = &sctp_memory_per_cpu_fw_alloc,
+
 	.sockets_allocated = &sctp_sockets_allocated,
 };
 
@@ -9700,7 +9704,10 @@ struct proto sctpv6_prot = {
 	.sysctl_wmem	= sysctl_sctp_wmem,
 	.memory_pressure = &sctp_memory_pressure,
 	.enter_memory_pressure = sctp_enter_memory_pressure,
+
 	.memory_allocated = &sctp_memory_allocated,
+	.per_cpu_fw_alloc = &sctp_memory_per_cpu_fw_alloc,
+
 	.sockets_allocated = &sctp_sockets_allocated,
 };
 #endif /* IS_ENABLED(CONFIG_IPV6) */