linux_dsm_epyc7002/include
Shay Agroskin 64109f1dc4 net/mlx5e: Replace PTP clock lock from RW lock to seq lock
Changed "priv.clock.lock" lock from 'rw_lock' to 'seq_lock'
in order to improve packet rate performance.

Tested on Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz.
Sent 64b packets between two peers connected by ConnectX-5,
and measured packet rate for the receiver in three modes:
	no time-stamping (base rate)
	time-stamping using rw_lock (old lock) for critical region
	time-stamping using seq_lock (new lock) for critical region
Only the receiver time stamped its packets.

The measured packet rate improvements are:

	Single flow (multiple TX rings to single RX ring):
		without timestamping:	  4.26 (M packets)/sec
		with rw-lock (old lock):  4.1  (M packets)/sec
		with seq-lock (new lock): 4.16 (M packets)/sec
		1.46% improvement

	Multiple flows (multiple TX rings to six RX rings):
		without timestamping: 	  22   (M packets)/sec
		with rw-lock (old lock):  11.7 (M packets)/sec
		with seq-lock (new lock): 21.3 (M packets)/sec
		82.05% improvement

The packet rate improvement is due to the lack of atomic operations
for the 'readers' by the seq-lock.
Since there are much more 'readers' than 'writers' contention
on this lock, almost all atomic operations are saved.
this results in a dramatic decrease in overall
cache misses.

Signed-off-by: Shay Agroskin <shayag@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2018-09-05 21:14:57 -07:00
..
acpi
asm-generic Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
clocksource
crypto
drm
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys
kvm
linux net/mlx5e: Replace PTP clock lock from RW lock to seq lock 2018-09-05 21:14:57 -07:00
math-emu
media
memory
misc
net mac80211: add an option for drivers to check if packets can be aggregated 2018-09-05 10:11:50 +02:00
pcmcia
ras
rdma
scsi
soc
sound
target
trace Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2018-08-24 13:19:27 -07:00
uapi nl80211: Add CAN_REPLACE_PTK0 API 2018-09-05 10:03:17 +02:00
video
xen