[PATCH net-next] tcp: align tcp_sock_write_rx group

[PATCH net-next] tcp: align tcp_sock_write_rx group

[Eric Dumazet]

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 <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
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 <edumazet@google.com>
---
 include/linux/tcp.h | 2 +-
 net/ipv4/tcp.c      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 988a30ef6bfe956fa573f1f18c8284aa382dc1cc..55399ee2a57e736b55ed067fc06ea620bbe62fd3 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 c82dc42f57c65df112f79080ff407cd98d11ce68..7e1b848398d04f2da2a91c3af97b1e2e3895b8ee 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);
-- 
2.44.0.278.ge034bb2e1d-goog

Re: [PATCH net-next] tcp: align tcp_sock_write_rx group

[Simon Horman]

On Fri, Mar 01, 2024 at 05:19:45PM +0000, Eric Dumazet wrote:
> 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 <sfr@canb.auug.org.au>
> Reported-by: kernel test robot <lkp@intel.com>
> 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 <edumazet@google.com>

Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested

...

Re: [PATCH net-next] tcp: align tcp_sock_write_rx group

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  1 Mar 2024 17:19:45 +0000 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net-next] tcp: align tcp_sock_write_rx group
    https://git.kernel.org/netdev/net-next/c/345a6e2631c1

You are awesome, thank you!
-- 
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