[PATCH net-next 2/7] mptcp: shrink mptcp_out_options struct
From: Mat Martineau <hidden>
Date: 2021-08-24 23:26:35
Also in:
mptcp
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
From: Paolo Abeni <pabeni@redhat.com> After the previous patch we can alias with a union several fields in mptcp_out_options. Such struct is stack allocated and memset() for each plain TCP out packet. Every saved byted counts. Before: pahole -EC mptcp_out_options # ... /* size: 136, cachelines: 3, members: 17 */ After: pahole -EC mptcp_out_options # ... /* size: 56, cachelines: 1, members: 9 */ Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <redacted> --- include/net/mptcp.h | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 8b5af683a818..3236010afa29 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h@@ -58,10 +58,6 @@ struct mptcp_addr_info { struct mptcp_out_options { #if IS_ENABLED(CONFIG_MPTCP) u16 suboptions; - u64 sndr_key; - u64 rcvr_key; - u64 ahmac; - struct mptcp_addr_info addr; struct mptcp_rm_list rm_list; u8 join_id; u8 backup;
@@ -69,11 +65,23 @@ struct mptcp_out_options { reset_transient:1, csum_reqd:1, allow_join_id0:1; - u32 nonce; - u64 thmac; - u32 token; - u8 hmac[20]; - struct mptcp_ext ext_copy; + union { + struct { + u64 sndr_key; + u64 rcvr_key; + }; + struct { + struct mptcp_addr_info addr; + u64 ahmac; + }; + struct mptcp_ext ext_copy; + struct { + u32 nonce; + u32 token; + u64 thmac; + u8 hmac[20]; + }; + }; #endif };
--
2.33.0