From d40ad865704b0a3547ca199acba102020ebb947e Mon Sep 17 00:00:00 2001 From: Bodong Wang Date: Fri, 12 Jan 2018 07:58:41 +0200 Subject: [PATCH] IB/core: Fix ib_wc structure size to remain in 64 bytes boundary commit cd2a6e7d384b043d5d029e39663061cebc949385 upstream. The change of slid from u16 to u32 results in sizeof(struct ib_wc) cross 64B boundary, which causes more cache misses. This patch rearranges the fields and remain the size to 64B. Pahole output before this change: struct ib_wc { union { u64 wr_id; /* 8 */ struct ib_cqe * wr_cqe; /* 8 */ }; /* 0 8 */ enum ib_wc_status status; /* 8 4 */ enum ib_wc_opcode opcode; /* 12 4 */ u32 vendor_err; /* 16 4 */ u32 byte_len; /* 20 4 */ struct ib_qp * qp; /* 24 8 */ union { __be32 imm_data; /* 4 */ u32 invalidate_rkey; /* 4 */ } ex; /* 32 4 */ u32 src_qp; /* 36 4 */ int wc_flags; /* 40 4 */ u16 pkey_index; /* 44 2 */ /* XXX 2 bytes hole, try to pack */ u32 slid; /* 48 4 */ u8 sl; /* 52 1 */ u8 dlid_path_bits; /* 53 1 */ u8 port_num; /* 54 1 */ u8 smac[6]; /* 55 6 */ /* XXX 1 byte hole, try to pack */ u16 vlan_id; /* 62 2 */ /* --- cacheline 1 boundary (64 bytes) --- */ u8 network_hdr_type; /* 64 1 */ /* size: 72, cachelines: 2, members: 17 */ /* sum members: 62, holes: 2, sum holes: 3 */ /* padding: 7 */ /* last cacheline: 8 bytes */ }; Pahole output after this change: struct ib_wc { union { u64 wr_id; /* 8 */ struct ib_cqe * wr_cqe; /* 8 */ }; /* 0 8 */ enum ib_wc_status status; /* 8 4 */ enum ib_wc_opcode opcode; /* 12 4 */ u32 vendor_err; /* 16 4 */ u32 byte_len; /* 20 4 */ struct ib_qp * qp; /* 24 8 */ union { __be32 imm_data; /* 4 */ u32 invalidate_rkey; /* 4 */ } ex; /* 32 4 */ u32 src_qp; /* 36 4 */ u32 slid; /* 40 4 */ int wc_flags; /* 44 4 */ u16 pkey_index; /* 48 2 */ u8 sl; /* 50 1 */ u8 dlid_path_bits; /* 51 1 */ u8 port_num; /* 52 1 */ u8 smac[6]; /* 53 6 */ /* XXX 1 byte hole, try to pack */ u16 vlan_id; /* 60 2 */ u8 network_hdr_type; /* 62 1 */ /* size: 64, cachelines: 1, members: 17 */ /* sum members: 62, holes: 1, sum holes: 1 */ /* padding: 1 */ }; Fixes: 7db20ecd1d97 ("IB/core: Change wc.slid from 16 to 32 bits") Signed-off-by: Bodong Wang Reviewed-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- include/rdma/ib_verbs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index e8608b2dc844..6533aa64f009 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -971,9 +971,9 @@ struct ib_wc { u32 invalidate_rkey; } ex; u32 src_qp; + u32 slid; int wc_flags; u16 pkey_index; - u32 slid; u8 sl; u8 dlid_path_bits; u8 port_num; /* valid only for DR SMPs on switches */ -- 2.11.0