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RDS: add receive message trace used by application

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Socket option to tap receive path latency in various stages
in nano seconds. It can be enabled on selective sockets using
using SO_RDS_MSG_RXPATH_LATENCY socket option. RDS will return
the data to application with RDS_CMSG_RXPATH_LATENCY in defined
format. Scope is left to add more trace points for future
without need of change in the interface.

Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
This commit is contained in:
Santosh Shilimkar 2016-07-04 22:35:15 -07:00
parent f9fb69adb6
commit 3289025aed
6 changed files with 109 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
include/uapi/linux/rds.h
View File

@ -52,6 +52,13 @@
#define RDS_GET_MR_FOR_DEST 7
#define SO_RDS_TRANSPORT 8
/* Socket option to tap receive path latency
* SO_RDS: SO_RDS_MSG_RXPATH_LATENCY
* Format used struct rds_rx_trace_so
*/
#define SO_RDS_MSG_RXPATH_LATENCY 10
/* supported values for SO_RDS_TRANSPORT */
#define RDS_TRANS_IB 0
#define RDS_TRANS_IWARP 1
@ -77,6 +84,12 @@
* the same as for the GET_MR setsockopt.
* RDS_CMSG_RDMA_STATUS (recvmsg)
* Returns the status of a completed RDMA operation.
* RDS_CMSG_RXPATH_LATENCY(recvmsg)
* Returns rds message latencies in various stages of receive
* path in nS. Its set per socket using SO_RDS_MSG_RXPATH_LATENCY
* socket option. Legitimate points are defined in
* enum rds_message_rxpath_latency. More points can be added in
* future. CSMG format is struct rds_cmsg_rx_trace.
*/
#define RDS_CMSG_RDMA_ARGS 1
#define RDS_CMSG_RDMA_DEST 2
@ -87,6 +100,7 @@
#define RDS_CMSG_ATOMIC_CSWP 7
#define RDS_CMSG_MASKED_ATOMIC_FADD 8
#define RDS_CMSG_MASKED_ATOMIC_CSWP 9
#define RDS_CMSG_RXPATH_LATENCY 11
#define RDS_INFO_FIRST 10000
#define RDS_INFO_COUNTERS 10000
@ -171,6 +185,25 @@ struct rds_info_rdma_connection {
uint32_t rdma_mr_size;
};
/* RDS message Receive Path Latency points */
enum rds_message_rxpath_latency {
RDS_MSG_RX_HDR_TO_DGRAM_START = 0,
RDS_MSG_RX_DGRAM_REASSEMBLE,
RDS_MSG_RX_DGRAM_DELIVERED,
RDS_MSG_RX_DGRAM_TRACE_MAX
};
struct rds_rx_trace_so {
u8 rx_traces;
u8 rx_trace_pos[RDS_MSG_RX_DGRAM_TRACE_MAX];
};
struct rds_cmsg_rx_trace {
u8 rx_traces;
u8 rx_trace_pos[RDS_MSG_RX_DGRAM_TRACE_MAX];
u64 rx_trace[RDS_MSG_RX_DGRAM_TRACE_MAX];
};
/*
* Congestion monitoring.
* Congestion control in RDS happens at the host connection

28
net/rds/af_rds.c
View File

@ -298,6 +298,30 @@ static int rds_enable_recvtstamp(struct sock *sk, char __user *optval,
return 0;
}
static int rds_recv_track_latency(struct rds_sock *rs, char __user *optval,
int optlen)
{
struct rds_rx_trace_so trace;
int i;
if (optlen != sizeof(struct rds_rx_trace_so))
return -EFAULT;
if (copy_from_user(&trace, optval, sizeof(trace)))
return -EFAULT;
rs->rs_rx_traces = trace.rx_traces;
for (i = 0; i < rs->rs_rx_traces; i++) {
if (trace.rx_trace_pos[i] > RDS_MSG_RX_DGRAM_TRACE_MAX) {
rs->rs_rx_traces = 0;
return -EFAULT;
}
rs->rs_rx_trace[i] = trace.rx_trace_pos[i];
}
return 0;
}
static int rds_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
@ -338,6 +362,9 @@ static int rds_setsockopt(struct socket *sock, int level, int optname,
ret = rds_enable_recvtstamp(sock->sk, optval, optlen);
release_sock(sock->sk);
break;
case SO_RDS_MSG_RXPATH_LATENCY:
ret = rds_recv_track_latency(rs, optval, optlen);
break;
default:
ret = -ENOPROTOOPT;
}
@ -484,6 +511,7 @@ static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
INIT_LIST_HEAD(&rs->rs_cong_list);
spin_lock_init(&rs->rs_rdma_lock);
rs->rs_rdma_keys = RB_ROOT;
rs->rs_rx_traces = 0;
spin_lock_bh(&rds_sock_lock);
list_add_tail(&rs->rs_item, &rds_sock_list);

4
net/rds/ib_recv.c
View File

@ -911,8 +911,12 @@ static void rds_ib_process_recv(struct rds_connection *conn,
ic->i_ibinc = ibinc;
hdr = &ibinc->ii_inc.i_hdr;
ibinc->ii_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] =
local_clock();
memcpy(hdr, ihdr, sizeof(*hdr));
ic->i_recv_data_rem = be32_to_cpu(hdr->h_len);
ibinc->ii_inc.i_rx_lat_trace[RDS_MSG_RX_START] =
local_clock();
rdsdebug("ic %p ibinc %p rem %u flag 0x%x\n", ic, ibinc,
ic->i_recv_data_rem, hdr->h_flags);

10
net/rds/rds.h
View File

@ -253,6 +253,11 @@ struct rds_ext_header_rdma_dest {
#define RDS_EXTHDR_GEN_NUM 6
#define __RDS_EXTHDR_MAX 16 /* for now */
#define RDS_RX_MAX_TRACES (RDS_MSG_RX_DGRAM_TRACE_MAX + 1)
#define RDS_MSG_RX_HDR 0
#define RDS_MSG_RX_START 1
#define RDS_MSG_RX_END 2
#define RDS_MSG_RX_CMSG 3
struct rds_incoming {
atomic_t i_refcount;
@ -265,6 +270,7 @@ struct rds_incoming {
rds_rdma_cookie_t i_rdma_cookie;
struct timeval i_rx_tstamp;
u64 i_rx_lat_trace[RDS_RX_MAX_TRACES];
};
struct rds_mr {
@ -575,6 +581,10 @@ struct rds_sock {
unsigned char rs_recverr,
rs_cong_monitor;
u32 rs_hash_initval;
/* Socket receive path trace points*/
u8 rs_rx_traces;
u8 rs_rx_trace[RDS_MSG_RX_DGRAM_TRACE_MAX];
};
static inline struct rds_sock *rds_sk_to_rs(const struct sock *sk)

32
net/rds/recv.c
View File

@ -43,6 +43,8 @@
void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
__be32 saddr)
{
int i;
atomic_set(&inc->i_refcount, 1);
INIT_LIST_HEAD(&inc->i_item);
inc->i_conn = conn;
@ -50,6 +52,9 @@ void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
inc->i_rdma_cookie = 0;
inc->i_rx_tstamp.tv_sec = 0;
inc->i_rx_tstamp.tv_usec = 0;
for (i = 0; i < RDS_RX_MAX_TRACES; i++)
inc->i_rx_lat_trace[i] = 0;
}
EXPORT_SYMBOL_GPL(rds_inc_init);
@ -373,6 +378,7 @@ void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
if (sock_flag(sk, SOCK_RCVTSTAMP))
do_gettimeofday(&inc->i_rx_tstamp);
rds_inc_addref(inc);
inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock();
list_add_tail(&inc->i_item, &rs->rs_recv_queue);
__rds_wake_sk_sleep(sk);
} else {
@ -534,7 +540,7 @@ static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie);
if (ret)
return ret;
goto out;
}
if ((inc->i_rx_tstamp.tv_sec != 0) &&
@ -543,10 +549,30 @@ static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
sizeof(struct timeval),
&inc->i_rx_tstamp);
if (ret)
return ret;
goto out;
}
return 0;
if (rs->rs_rx_traces) {
struct rds_cmsg_rx_trace t;
int i, j;
inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
t.rx_traces = rs->rs_rx_traces;
for (i = 0; i < rs->rs_rx_traces; i++) {
j = rs->rs_rx_trace[i];
t.rx_trace_pos[i] = j;
t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] -
inc->i_rx_lat_trace[j];
}
ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY,
sizeof(t), &t);
if (ret)
goto out;
}
out:
return ret;
}
int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,

5
net/rds/tcp_recv.c
View File

@ -180,6 +180,9 @@ static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
rdsdebug("alloced tinc %p\n", tinc);
rds_inc_path_init(&tinc->ti_inc, cp,
cp->cp_conn->c_faddr);
tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] =
local_clock();
/*
* XXX * we might be able to use the __ variants when
* we've already serialized at a higher level.
@ -204,6 +207,8 @@ static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
/* could be 0 for a 0 len message */
tc->t_tinc_data_rem =
be32_to_cpu(tinc->ti_inc.i_hdr.h_len);
tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_START] =
local_clock();
}
}