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 bedb4f86b0fea1ce13a10895182681c37ef7e904..e1a1c8aedc79753f63eb7c81757639ea20829f0d 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 a772510b2aa58a922dc4dd5bd7cb7f7f0c1ce0e3..f8ae2c4ade141d27e4af3376f5a177e46d5b39ea 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 19573ee64a0f18cf55df34ace1956e9c3e20172c..49f43c54cfb0e3ac85c1a6202f3d6a2f1ca6d0ba 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 e1ff3a37599614b18a0b621534019a7bd71ea901..c7142213fc2112c9e423caa5e6d84bafeaca9936 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 af37af3ab727bffeebe5c41d84cb7c130f49c50d..d3e621a11a1aa4cafb62eb53ddc0ed1ca517a7fe 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 ebb95d8bc6819f72842fd1567e73fcef4f1e0ed0..6bbdadbd5fecccfb7de99f05c6fb179393e162f2 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 0590f566379d7d07dfdd1b0ae808b9d8964eb5aa..8a406be25a3a6dee687a6a02ea0b6a28428abb86 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 a60bec9b14f14a5b2d271f9965b5fca3d2a440c8..2cec542437f74eba9540fc464ee70d8b0bc0be79 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,