tcp: move sysctl_tcp_shrink_window to netns_ipv4_read_txrx group

Commit 18fd64d25422 ("netns-ipv4: reorganize netns_ipv4 fast path
variables") missed that __tcp_select_window() is reading
net->ipv4.sysctl_tcp_shrink_window.

Move this field to netns_ipv4_read_txrx group, as __tcp_select_window()
is used both in tx and rx paths.

Saves a potential cache line miss.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260307092214.2433548-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 4c249aeaf7f12f8237232a6f3d3f3ed56d0a53d4..38624beff9b34161327d7549fcd0f041c9c91679 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -74,6 +74,7 @@ struct netns_ipv4 {
 
        /* TXRX readonly hotpath cache lines */
        __cacheline_group_begin(netns_ipv4_read_txrx);
+       u8              sysctl_tcp_shrink_window;
        __cacheline_group_end(netns_ipv4_read_txrx);
 
        /* RX readonly hotpath cache line */
@@ -122,7 +123,6 @@ struct netns_ipv4 {
 #endif
        bool                    fib_has_custom_local_routes;
        bool                    fib_offload_disabled;
-       u8                      sysctl_tcp_shrink_window;
 #ifdef CONFIG_IP_ROUTE_CLASSID
        atomic_t                fib_num_tclassid_users;
 #endif