Hi， Jerin
please see my performance test below
On 11/2/2017 3:04 AM, Jerin Jacob Wrote:
[...]
Should it be like instead?
+#else
+ *old_head = __atomic_load_n(&r->cons.head, __ATOMIC_ACQUIRE);
+ const uint32_t prod_tail = __atomic_load_n(&r->prod.tail,
__ATOMIC_ACQUIRE);
It would be nice to see how much overhead it gives.ie back to back
__ATOMIC_ACQUIRE.
I can NOT test ring_perf_autotest in our server because of the something
wrong in PMU counter.
All the return value of rte_rdtsc is 0 with and without your provided ko
module. I am still
investigating the reason.
I ever tested the difference with my debug patch, the difference is
minor, less than +-1%
--
Cheers,
Jia
Cheers,
Jia
On 10/31/2017 7:14 PM, Jerin Jacob Wrote:
-----Original Message-----
Date: Tue, 31 Oct 2017 10:55:15 +0800
From: Jia He <hejia...@gmail.com>
To: Jerin Jacob <jerin.ja...@caviumnetworks.com>
Cc: "Ananyev, Konstantin" <konstantin.anan...@intel.com>, "Zhao, Bing"
<iloveth...@163.com>, Olivier MATZ <olivier.m...@6wind.com>,
"dev@dpdk.org" <dev@dpdk.org>, "jia...@hxt-semitech.com"
<jia...@hxt-semitech.com>, "jie2....@hxt-semitech.com"
<jie2....@hxt-semitech.com>, "bing.z...@hxt-semitech.com"
<bing.z...@hxt-semitech.com>, "Richardson, Bruce"
<bruce.richard...@intel.com>
Subject: Re: [dpdk-dev] [PATCH] ring: guarantee ordering of cons/prod
loading when doing enqueue/dequeue
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101
Thunderbird/52.4.0
Hi Jerin
Hi Jia,
Do you think next step whether I need to implement the load_acquire half
barrier as per freebsd
I did a quick prototype using C11 memory model(ACQUIRE/RELEASE) schematics
and tested on two arm64 platform in Cavium(Platform A: Non arm64 OOO machine)
and Platform B: arm64 OOO machine)
smp_rmb() performs better in Platform A:
acquire/release semantics perform better in platform B:
Here is the patch:
https://github.com/jerinjacobk/mytests/blob/master/ring/0001-ring-using-c11-memory-model.patch
In terms of next step:
- I am not sure the cost associated with acquire/release semantics on x86 or
ppc.
IMO, We need to have both options under conditional compilation
flags and let the target platform choose the best one.
Thoughts?
Here is the performance numbers:
- Both platforms are running at different frequency, So absolute numbers does
not
matter, Just check the relative numbers.
Platform A: Performance numbers:
================================
no patch(Non arm64 OOO machine)
-------------------------------
SP/SC single enq/dequeue: 40
MP/MC single enq/dequeue: 282
SP/SC burst enq/dequeue (size: 8): 11
MP/MC burst enq/dequeue (size: 8): 42
SP/SC burst enq/dequeue (size: 32): 8
MP/MC burst enq/dequeue (size: 32): 16
### Testing empty dequeue ###
SC empty dequeue: 8.01
MC empty dequeue: 11.01
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 11.30
MP/MC bulk enq/dequeue (size: 8): 42.85
SP/SC bulk enq/dequeue (size: 32): 8.25
MP/MC bulk enq/dequeue (size: 32): 16.46
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 20.62
MP/MC bulk enq/dequeue (size: 8): 56.30
SP/SC bulk enq/dequeue (size: 32): 10.94
MP/MC bulk enq/dequeue (size: 32): 18.66
Test OK
# smp_rmb() patch((Non OOO arm64 machine)
http://dpdk.org/dev/patchwork/patch/30029/
-----------------------------------------
SP/SC single enq/dequeue: 42
MP/MC single enq/dequeue: 291
SP/SC burst enq/dequeue (size: 8): 12
MP/MC burst enq/dequeue (size: 8): 44
SP/SC burst enq/dequeue (size: 32): 8
MP/MC burst enq/dequeue (size: 32): 16
### Testing empty dequeue ###
SC empty dequeue: 13.01
MC empty dequeue: 15.01
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 11.60
MP/MC bulk enq/dequeue (size: 8): 44.32
SP/SC bulk enq/dequeue (size: 32): 8.60
MP/MC bulk enq/dequeue (size: 32): 16.50
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 20.95
MP/MC bulk enq/dequeue (size: 8): 56.90
SP/SC bulk enq/dequeue (size: 32): 10.90
MP/MC bulk enq/dequeue (size: 32): 18.78
Test OK
RTE>>
# c11 memory model patch((Non OOO arm64 machine)
https://github.com/jerinjacobk/mytests/blob/master/ring/0001-ring-using-c11-memory-model.patch
---------------------------------------------------------------------------------------------
### Testing single element and burst enq/deq ###
SP/SC single enq/dequeue: 197
MP/MC single enq/dequeue: 328
SP/SC burst enq/dequeue (size: 8): 31
MP/MC burst enq/dequeue (size: 8): 50
SP/SC burst enq/dequeue (size: 32): 13
MP/MC burst enq/dequeue (size: 32): 18
### Testing empty dequeue ###
SC empty dequeue: 13.01
MC empty dequeue: 18.02
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 30.95
MP/MC bulk enq/dequeue (size: 8): 50.30
SP/SC bulk enq/dequeue (size: 32): 13.27
MP/MC bulk enq/dequeue (size: 32): 18.11
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 43.38
MP/MC bulk enq/dequeue (size: 8): 64.42
SP/SC bulk enq/dequeue (size: 32): 16.71
MP/MC bulk enq/dequeue (size: 32): 22.21
Platform B: Performance numbers:
==============================
#no patch(OOO arm64 machine)
----------------------------
### Testing single element and burst enq/deq ###
SP/SC single enq/dequeue: 81
MP/MC single enq/dequeue: 207
SP/SC burst enq/dequeue (size: 8): 15
MP/MC burst enq/dequeue (size: 8): 31
SP/SC burst enq/dequeue (size: 32): 7
MP/MC burst enq/dequeue (size: 32): 11
### Testing empty dequeue ###
SC empty dequeue: 3.00
MC empty dequeue: 5.00
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 15.38
MP/MC bulk enq/dequeue (size: 8): 30.64
SP/SC bulk enq/dequeue (size: 32): 7.25
MP/MC bulk enq/dequeue (size: 32): 11.06
### Testing using two hyperthreads ###
SP/SC bulk enq/dequeue (size: 8): 31.51
MP/MC bulk enq/dequeue (size: 8): 49.38
SP/SC bulk enq/dequeue (size: 32): 14.32
MP/MC bulk enq/dequeue (size: 32): 15.89
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 72.66
MP/MC bulk enq/dequeue (size: 8): 121.89
SP/SC bulk enq/dequeue (size: 32): 16.88
MP/MC bulk enq/dequeue (size: 32): 24.23
Test OK
RTE>>
# smp_rmb() patch((OOO arm64 machine)
http://dpdk.org/dev/patchwork/patch/30029/
-------------------------------------------
### Testing single element and burst enq/deq ###
SP/SC single enq/dequeue: 152
MP/MC single enq/dequeue: 265
SP/SC burst enq/dequeue (size: 8): 24
MP/MC burst enq/dequeue (size: 8): 39
SP/SC burst enq/dequeue (size: 32): 9
MP/MC burst enq/dequeue (size: 32): 13
### Testing empty dequeue ###
SC empty dequeue: 31.01
MC empty dequeue: 32.01
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 24.26
MP/MC bulk enq/dequeue (size: 8): 39.52
SP/SC bulk enq/dequeue (size: 32): 9.47
MP/MC bulk enq/dequeue (size: 32): 13.31
### Testing using two hyperthreads ###
SP/SC bulk enq/dequeue (size: 8): 40.29
MP/MC bulk enq/dequeue (size: 8): 59.57
SP/SC bulk enq/dequeue (size: 32): 17.34
MP/MC bulk enq/dequeue (size: 32): 21.58
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 79.05
MP/MC bulk enq/dequeue (size: 8): 153.46
SP/SC bulk enq/dequeue (size: 32): 26.41
MP/MC bulk enq/dequeue (size: 32): 38.37
Test OK
RTE>>
# c11 memory model patch((OOO arm64 machine)
https://github.com/jerinjacobk/mytests/blob/master/ring/0001-ring-using-c11-memory-model.patch
----------------------------------------------------------------------------------------------
### Testing single element and burst enq/deq ###
SP/SC single enq/dequeue: 98
MP/MC single enq/dequeue: 130
SP/SC burst enq/dequeue (size: 8): 18
MP/MC burst enq/dequeue (size: 8): 22
SP/SC burst enq/dequeue (size: 32): 7
MP/MC burst enq/dequeue (size: 32): 9
### Testing empty dequeue ###
SC empty dequeue: 4.00
MC empty dequeue: 5.00
### Testing using a single lcore ###
SP/SC bulk enq/dequeue (size: 8): 17.40
MP/MC bulk enq/dequeue (size: 8): 22.88
SP/SC bulk enq/dequeue (size: 32): 7.62
MP/MC bulk enq/dequeue (size: 32): 8.96
### Testing using two hyperthreads ###
SP/SC bulk enq/dequeue (size: 8): 20.24
MP/MC bulk enq/dequeue (size: 8): 25.83
SP/SC bulk enq/dequeue (size: 32): 12.21
MP/MC bulk enq/dequeue (size: 32): 13.20
### Testing using two physical cores ###
SP/SC bulk enq/dequeue (size: 8): 67.54
MP/MC bulk enq/dequeue (size: 8): 124.63
SP/SC bulk enq/dequeue (size: 32): 21.13
MP/MC bulk enq/dequeue (size: 32): 28.44
Test OK
RTE>>quit
or find any other performance test case to compare the performance impact?
As far as I know, ring_perf_autotest is the better performance test.
If you have trouble in using "High-resolution cycle counter" in your platform
then also
you can use ring_perf_auto test to compare the performance(as relative
number matters)
Jerin
Thanks for any suggestions.
Cheers,
Jia
