tmp_suning_uos_patched/net
Chuck Lever b22602a673 SUNRPC: Ensure all transports set rq_xtime consistently
The RPC client uses the rq_xtime field in each RPC request to determine the
round-trip time of the request.  Currently, the rq_xtime field is
initialized by each transport just before it starts enqueing a request to
be sent.  However, transports do not handle initializing this value
consistently; sometimes they don't initialize it at all.

To make the measurement of request round-trip time consistent for all
RPC client transport capabilities, pull rq_xtime initialization into the
RPC client's generic transport logic.  Now all transports will get a
standardized RTT measure automatically, from:

  xprt_transmit()

to

  xprt_complete_rqst()

This makes round-trip time calculation more accurate for the TCP transport.
The socket ->sendmsg() method can return "-EAGAIN" if the socket's output
buffer is full, so the TCP transport's ->send_request() method may call
the ->sendmsg() method repeatedly until it gets all of the request's bytes
queued in the socket's buffer.

Currently, the TCP transport sets the rq_xtime field every time through
that loop so the final value is the timestamp just before the *last* call
to the underlying socket's ->sendmsg() method.  After this patch, the
rq_xtime field contains a timestamp that reflects the time just before the
*first* call to ->sendmsg().

This is consequential under heavy workloads because large requests often
take multiple ->sendmsg() calls to get all the bytes of a request queued.
The TCP transport causes the request to sleep until the remote end of the
socket has received enough bytes to clear space in the socket's local
output buffer.  This delay can be quite significant.

The method introduced by this patch is a more accurate measure of RTT
for stream transports, since the server can cause enough back pressure
to delay (ie increase the latency of) requests from the client.

Additionally, this patch corrects the behavior of the RDMA transport, which
entirely neglected to initialize the rq_xtime field.  RPC performance
metrics for RDMA transports now display correct RPC request round trip
times.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Tom Talpey <thomas.talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-07-09 12:09:15 -04:00
..
9p 9p: fix error path during early mount 2008-05-14 19:23:27 -05:00
802 [TR] net/802/tr.c: sysctl_tr_rif_timeout static 2008-01-31 19:28:31 -08:00
8021q vlan: Use bitmask of feature flags instead of seperate feature bits 2008-05-23 00:27:50 -07:00
appletalk [NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS. 2008-03-26 04:39:53 +09:00
atm atm: [br2864] fix routed vcmux support 2008-06-16 17:18:18 -07:00
ax25 ax25: Fix NULL pointer dereference and lockup. 2008-06-03 14:53:46 -07:00
bluetooth bluetooth: rfcomm_dev_state_change deadlock fix 2008-06-03 14:27:17 -07:00
bridge bridge: fix use-after-free in br_cleanup_bridges() 2008-07-03 03:53:42 -07:00
can can: add sanity checks 2008-07-05 23:38:43 -07:00
core net: fib_rules: fix error code for unsupported families 2008-07-01 19:59:37 -07:00
dccp dccp: Bug in initial acknowledgment number assignment 2008-06-11 11:19:10 +01:00
decnet ip: Use inline function dst_metric() instead of direct access to dst->metric[] 2008-05-04 22:14:42 -07:00
econet net: Allow netdevices to specify needed head/tailroom 2008-05-12 20:48:31 -07:00
ethernet [NET]: Return more appropriate error from eth_validate_addr(). 2008-04-13 22:45:40 -07:00
ieee80211 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-04-14 02:30:23 -07:00
ipv4 tcp: fix a size_t < 0 comparison in tcp_read_sock 2008-07-03 03:31:21 -07:00
ipv6 ipv6 route: Convert rt6_device_match() to use RT6_LOOKUP_F_xxx flags. 2008-06-27 20:14:54 -07:00
ipx [NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS. 2008-03-26 04:39:53 +09:00
irda irda: Sock leak on error path in irda_create. 2008-06-03 15:18:36 -07:00
iucv iucv: Delay bus registration until core is ready. 2008-04-10 02:12:45 -07:00
key ipsec: pfkey should ignore events when no listeners 2008-06-10 14:25:34 -07:00
lapb [LAPB] net/lapb/lapb_iface.c: use LIST_HEAD instead of LIST_HEAD_INIT 2008-01-28 14:56:52 -08:00
llc llc: Fix double accounting of received packets 2008-05-30 02:57:29 -07:00
mac80211 net-sched: change tcf_destroy_chain() to clear start of filter list 2008-07-01 19:52:38 -07:00
netfilter netfilter: nf_conntrack_tcp: fixing to check the lower bound of valid ACK 2008-06-30 12:41:30 -07:00
netlabel netlabel: Fix a problem when dumping the default IPv6 static labels 2008-06-27 20:12:32 -07:00
netlink netlink: Unneeded local variable 2008-07-01 19:55:09 -07:00
netrom [NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS. 2008-03-26 04:39:55 +09:00
packet net: Allow netdevices to specify needed head/tailroom 2008-05-12 20:48:31 -07:00
rfkill rfkill: Fix device type check when toggling states 2008-04-15 15:04:35 -04:00
rose rose: Wrong list_lock argument in rose_node seqops 2008-05-02 17:03:22 -07:00
rxrpc net: Add missing braces to multi-statement if()s 2008-05-02 16:20:10 -07:00
sched net-sched: fix filter destruction in atm/hfsc qdisc destruction 2008-07-01 19:53:09 -07:00
sctp sctp: Make sure N * sizeof(union sctp_addr) does not overflow. 2008-06-20 22:04:34 -07:00
sunrpc SUNRPC: Ensure all transports set rq_xtime consistently 2008-07-09 12:09:15 -04:00
tipc tipc: Increase buffer header to support worst-case device 2008-05-08 21:38:24 -07:00
unix af_unix: fix 'poll for write'/connected DGRAM sockets 2008-06-27 19:34:18 -07:00
wanrouter [WANROUTER]: Use proc_create() to setup ->proc_fops first 2008-02-28 14:15:56 -08:00
wireless mac80211: implement EU regulatory domain 2008-06-25 10:31:29 -04:00
x25 [NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS. 2008-03-26 04:39:55 +09:00
xfrm xfrm: xfrm_algo: correct usage of RIPEMD-160 2008-06-04 12:04:55 -07:00
compat.c net: Add compat support for getsockopt (MCAST_MSFILTER) 2008-04-29 03:23:22 -07:00
Kconfig [IPV4]: Fix size description of CONFIG_INET. 2008-03-04 15:18:22 +09:00
Makefile [CAN]: Add PF_CAN core module 2008-01-28 14:54:10 -08:00
nonet.c
socket.c net: Unexport move_addr_to_{kernel,user} 2008-04-23 03:37:49 -07:00
sysctl_net.c net: fix returning void-valued expression warnings 2008-05-01 02:47:38 -07:00
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