linux/net
Sunil Muthuswamy 14a1eaa882 hv_sock: perf: loop in send() to maximize bandwidth
Currently, the hv_sock send() iterates once over the buffer, puts data into
the VMBUS channel and returns. It doesn't maximize on the case when there
is a simultaneous reader draining data from the channel. In such a case,
the send() can maximize the bandwidth (and consequently minimize the cpu
cycles) by iterating until the channel is found to be full.

Perf data:
Total Data Transfer: 10GB/iteration
Single threaded reader/writer, Linux hvsocket writer with Windows hvsocket
reader
Packet size: 64KB
CPU sys time was captured using the 'time' command for the writer to send
10GB of data.
'Send Buffer Loop' is with the patch applied.
The values below are over 10 iterations.

|--------------------------------------------------------|
|        |        Current        |   Send Buffer Loop    |
|--------------------------------------------------------|
|        | Throughput | CPU sys  | Throughput | CPU sys  |
|        | (MB/s)     | time (s) | (MB/s)     | time (s) |
|--------------------------------------------------------|
| Min    |     407    |   7.048  |    401     |  5.958   |
|--------------------------------------------------------|
| Max    |     455    |   7.563  |    542     |  6.993   |
|--------------------------------------------------------|
| Avg    |     440    |   7.411  |    451     |  6.639   |
|--------------------------------------------------------|
| Median |     446    |   7.417  |    447     |  6.761   |
|--------------------------------------------------------|

Observation:
1. The avg throughput doesn't really change much with this change for this
scenario. This is most probably because the bottleneck on throughput is
somewhere else.
2. The average system (or kernel) cpu time goes down by 10%+ with this
change, for the same amount of data transfer.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-22 18:00:36 -07:00
..
6lowpan treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
9p treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
802 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
appletalk treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
atm treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ax25 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
batman-adv This feature/cleanup patchset includes the following patches: 2019-05-09 09:44:17 -07:00
bluetooth treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bpf treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bpfilter treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bridge treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
caif SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
can treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ceph treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
core neighbor: Add tracepoint to __neigh_create 2019-05-22 17:50:24 -07:00
dcb treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
dccp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
decnet treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dns_resolver treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
dsa treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ethernet treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hsr treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ieee802154 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ife treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ipv4 net: Set strict_start_type for routes and rules 2019-05-22 17:50:24 -07:00
ipv6 net: Set strict_start_type for routes and rules 2019-05-22 17:50:24 -07:00
iucv treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
kcm treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
key treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
l2tp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
l3mdev treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
lapb treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
llc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mac80211 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mac802154 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mpls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ncsi treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
netfilter treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlabel treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
netrom treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nfc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
nsh treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
openvswitch treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
packet treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
phonet SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
psample treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
rds treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
rfkill treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
rose treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
rxrpc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sched treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 11 2019-05-21 11:28:45 +02:00
sctp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
smc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
strparser treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sunrpc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
switchdev treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
tls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
unix net: Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics. 2019-05-22 10:36:35 -07:00
vmw_vsock hv_sock: perf: loop in send() to maximize bandwidth 2019-05-22 18:00:36 -07:00
wimax treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
wireless treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
x25 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xdp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xfrm SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
compat.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile net: split out functions related to registering inflight socket files 2019-02-28 08:24:23 -07:00
socket.c net: fix kernel-doc warnings for socket.c 2019-05-19 10:33:22 -07:00
sysctl_net.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00