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Revert "net: group sk_backlog and sk_receive_queue"

This reverts commit 4effb335b5dab08cb6e2c38d038910f8b527cfc9.

This was a benefit for UDP flood case, which was later greatly improved
with commits 6471658dc66c ("udp: use skb_attempt_defer_free()")
and b650bf0977d3 ("udp: remove busylock and add per NUMA queues").

Apparently blamed commit added a regression for RAW sockets, possibly
because they do not use the dual RX queue strategy that UDP has.

sock_queue_rcv_skb_reason() and RAW recvmsg() compete for sk_receive_buf
and sk_rmem_alloc changes, and them being in the same
cache line reduce performance.

Fixes: 4effb335b5da ("net: group sk_backlog and sk_receive_queue")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202509281326.f605b4eb-lkp@intel.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250929182112.824154-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

authored by

Eric Dumazet and committed by
Jakub Kicinski 7d452516 9dd4e022

+1 -1
+1 -1
include/net/sock.h
··· 395 395 396 396 atomic_t sk_drops; 397 397 __s32 sk_peek_off; 398 + struct sk_buff_head sk_error_queue; 398 399 struct sk_buff_head sk_receive_queue; 399 400 /* 400 401 * The backlog queue is special, it is always used with ··· 413 412 } sk_backlog; 414 413 #define sk_rmem_alloc sk_backlog.rmem_alloc 415 414 416 - struct sk_buff_head sk_error_queue; 417 415 __cacheline_group_end(sock_write_rx); 418 416 419 417 __cacheline_group_begin(sock_read_rx);