udp: move udp_memory_allocated into net_aligned_data

____cacheline_aligned_in_smp attribute only makes sure to align
a field to a cache line. It does not prevent the linker to use
the remaining of the cache line for other variables, causing
potential false sharing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/aligned_data.h b/include/net/aligned_data.h
index bedb4f8..e1a1c8a 100644 (file)
--- a/include/net/aligned_data.h
+++ b/include/net/aligned_data.h
@@ -13,6 +13,7 @@ struct net_aligned_data {
        atomic64_t      net_cookie ____cacheline_aligned_in_smp;
 #if defined(CONFIG_INET)
        atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp;
+       atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
 #endif
 };
 

diff --git a/include/net/udp.h b/include/net/udp.h
index a772510..f8ae2c4 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -205,7 +205,6 @@ static inline void udp_hash4_dec(struct udp_hslot *hslot2)
 
 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 */

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 19573ee..49f43c5 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -127,8 +127,6 @@ struct udp_table udp_table __read_mostly;
 long sysctl_udp_mem[3] __read_mostly;
 EXPORT_IPV6_MOD(sysctl_udp_mem);
 
-atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
-EXPORT_IPV6_MOD(udp_memory_allocated);
 DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
 EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
 
@@ -3235,7 +3233,7 @@ struct proto udp_prot = {
 #ifdef CONFIG_BPF_SYSCALL
        .psock_update_sk_prot   = udp_bpf_update_proto,
 #endif
-       .memory_allocated       = &udp_memory_allocated,
+       .memory_allocated       = &net_aligned_data.udp_memory_allocated,
        .per_cpu_fw_alloc       = &udp_memory_per_cpu_fw_alloc,
 
        .sysctl_mem             = sysctl_udp_mem,

diff --git a/net/ipv4/udp_impl.h b/net/ipv4/udp_impl.h
index e1ff3a3..c714221 100644 (file)
--- a/net/ipv4/udp_impl.h
+++ b/net/ipv4/udp_impl.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _UDP4_IMPL_H
 #define _UDP4_IMPL_H
+#include <net/aligned_data.h>
 #include <net/udp.h>
 #include <net/udplite.h>
 #include <net/protocol.h>

diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
index af37af3..d3e621a 100644 (file)
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -60,7 +60,7 @@ struct proto  udplite_prot = {
        .rehash            = udp_v4_rehash,
        .get_port          = udp_v4_get_port,
 
-       .memory_allocated  = &udp_memory_allocated,
+       .memory_allocated  = &net_aligned_data.udp_memory_allocated,
        .per_cpu_fw_alloc  = &udp_memory_per_cpu_fw_alloc,
 
        .sysctl_mem        = sysctl_udp_mem,

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index ebb95d8..6bbdadb 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1925,7 +1925,7 @@ struct proto udpv6_prot = {
        .psock_update_sk_prot   = udp_bpf_update_proto,
 #endif
 
-       .memory_allocated       = &udp_memory_allocated,
+       .memory_allocated       = &net_aligned_data.udp_memory_allocated,
        .per_cpu_fw_alloc       = &udp_memory_per_cpu_fw_alloc,
 
        .sysctl_mem             = sysctl_udp_mem,

diff --git a/net/ipv6/udp_impl.h b/net/ipv6/udp_impl.h
index 0590f56..8a406be 100644 (file)
--- a/net/ipv6/udp_impl.h
+++ b/net/ipv6/udp_impl.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _UDP6_IMPL_H
 #define _UDP6_IMPL_H
+#include <net/aligned_data.h>
 #include <net/udp.h>
 #include <net/udplite.h>
 #include <net/protocol.h>

diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c
index a60bec9..2cec542 100644 (file)
--- a/net/ipv6/udplite.c
+++ b/net/ipv6/udplite.c
@@ -59,7 +59,7 @@ struct proto udplitev6_prot = {
        .rehash            = udp_v6_rehash,
        .get_port          = udp_v6_get_port,
 
-       .memory_allocated  = &udp_memory_allocated,
+       .memory_allocated  = &net_aligned_data.udp_memory_allocated,
        .per_cpu_fw_alloc  = &udp_memory_per_cpu_fw_alloc,
 
        .sysctl_mem        = sysctl_udp_mem,