This is a note to let you know that I've just added the patch titled
IB/core: Fix ib_wc structure size to remain in 64 bytes boundary
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ib-core-fix-ib_wc-structure-size-to-remain-in-64-bytes-boundary.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cd2a6e7d384b043d5d029e39663061cebc949385 Mon Sep 17 00:00:00 2001
From: Bodong Wang <bodong@xxxxxxxxxxxx>
Date: Fri, 12 Jan 2018 07:58:41 +0200
Subject: IB/core: Fix ib_wc structure size to remain in 64 bytes boundary
From: Bodong Wang <bodong@xxxxxxxxxxxx>
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 <bodong@xxxxxxxxxxxx>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/rdma/ib_verbs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -983,9 +983,9 @@ 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 */
Patches currently in stable-queue which might be from bodong@xxxxxxxxxxxx are
queue-4.15/ib-core-fix-ib_wc-structure-size-to-remain-in-64-bytes-boundary.patch