From 99123622050f10ca9148a0fffba2de0afd6cdfff Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 27 Feb 2024 19:27:21 +0000 Subject: tcp: remove some holes in struct tcp_sock By moving some fields around, this patch shrinks holes size from 56 to 32, saving 24 bytes on 64bit arches. After the patch pahole gives the following for 'struct tcp_sock': /* size: 2304, cachelines: 36, members: 162 */ /* sum members: 2234, holes: 6, sum holes: 32 */ /* sum bitfield members: 34 bits, bit holes: 5, sum bit holes: 14 bits */ /* padding: 32 */ /* paddings: 3, sum paddings: 10 */ /* forced alignments: 1, forced holes: 1, sum forced holes: 12 */ Signed-off-by: Eric Dumazet Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20240227192721.3558982-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/tcp.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/tcp.h') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index a1c47a6d69b0..988a30ef6bfe 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -264,10 +264,10 @@ struct tcp_sock { u32 pushed_seq; /* Last pushed seq, required to talk to windows */ u32 lsndtime; u32 mdev_us; /* medium deviation */ + u32 rtt_seq; /* sequence number to update rttvar */ u64 tcp_wstamp_ns; /* departure time for next sent data packet */ u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */ u64 tcp_mstamp; /* most recent packet received/sent */ - u32 rtt_seq; /* sequence number to update rttvar */ struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */ struct sk_buff *highest_sack; /* skb just after the highest * skb with SACKed bit set @@ -350,7 +350,6 @@ struct tcp_sock { u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups * total number of DSACK blocks received */ - u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */ u32 compressed_ack_rcv_nxt; struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ @@ -384,12 +383,12 @@ struct tcp_sock { syn_fastopen_ch:1, /* Active TFO re-enabling probe */ syn_data_acked:1;/* data in SYN is acked by SYN-ACK */ + u8 keepalive_probes; /* num of allowed keep alive probes */ u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ /* RTT measurement */ u32 mdev_max_us; /* maximal mdev for the last rtt period */ - u8 keepalive_probes; /* num of allowed keep alive probes */ u32 reord_seen; /* number of data packet reordering events */ /* @@ -402,6 +401,7 @@ struct tcp_sock { u32 prior_cwnd; /* cwnd right before starting loss recovery */ u32 prr_delivered; /* Number of newly delivered packets to * receiver in Recovery. */ + u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */ struct hrtimer pacing_timer; struct hrtimer compressed_ack_timer; @@ -477,8 +477,8 @@ struct tcp_sock { bool is_mptcp; #endif #if IS_ENABLED(CONFIG_SMC) - bool (*smc_hs_congested)(const struct sock *sk); bool syn_smc; /* SYN includes SMC */ + bool (*smc_hs_congested)(const struct sock *sk); #endif #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) -- cgit v1.2.3 From 345a6e2631c1267221b684e110bba03e4c26ece0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 1 Mar 2024 17:19:45 +0000 Subject: tcp: align tcp_sock_write_rx group Stephen Rothwell and kernel test robot reported that some arches (parisc, hexagon) and/or compilers would not like blamed commit. Lets make sure tcp_sock_write_rx group does not start with a hole. While we are at it, correct tcp_sock_write_tx CACHELINE_ASSERT_GROUP_SIZE() since after the blamed commit, we went to 105 bytes. Fixes: 99123622050f ("tcp: remove some holes in struct tcp_sock") Reported-by: Stephen Rothwell Reported-by: kernel test robot Link: https://lore.kernel.org/netdev/20240301121108.5d39e4f9@canb.auug.org.au/ Closes: https://lore.kernel.org/oe-kbuild-all/202403011451.csPYOS3C-lkp@intel.com/ Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Tested-by: Simon Horman # build-tested Link: https://lore.kernel.org/r/20240301171945.2958176-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/tcp.h | 2 +- net/ipv4/tcp.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/tcp.h') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 988a30ef6bfe..55399ee2a57e 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -304,7 +304,7 @@ struct tcp_sock { __cacheline_group_end(tcp_sock_write_txrx); /* RX read-write hotpath cache lines */ - __cacheline_group_begin(tcp_sock_write_rx); + __cacheline_group_begin(tcp_sock_write_rx) __aligned(8); u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived * sum(delta(rcv_nxt)), or how many bytes diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c82dc42f57c6..7e1b848398d0 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4651,7 +4651,7 @@ static void __init tcp_struct_check(void) CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tsorted_sent_queue); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, highest_sack); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, ecn_flags); - CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_tx, 113); + CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_tx, 105); /* TXRX read-write hotpath cache lines */ CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, pred_flags); -- cgit v1.2.3