Re: [PATCH RFC 00/16] A new RCU implementation based on a fast consensus protocol
From: Lihao Liang
Date: Sat Jan 27 2018 - 02:22:51 EST
On Thu, Jan 25, 2018 at 5:53 AM, Paul E. McKenney
<paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Jan 23, 2018 at 03:59:25PM +0800, lianglihao@xxxxxxxxxx wrote:
>> From: Lihao Liang <lianglihao@xxxxxxxxxx>
>>
>> Dear Paul,
>>
>> This patch set implements a preemptive version of RCU (PRCU) based on the following paper:
>>
>> Fast Consensus Using Bounded Staleness for Scalable Read-mostly Synchronization.
>> Haibo Chen, Heng Zhang, Ran Liu, Binyu Zang, and Haibing Guan.
>> IEEE Transactions on Parallel and Distributed Systems (TPDS), 2016.
>> https://dl.acm.org/citation.cfm?id=3024114.3024143
>>
>> We have also added preliminary callback-handling support. Thus, the current version
>> provides APIs prcu_read_lock(), prcu_read_unlock(), synchronize_prcu(), call_prcu(),
>> and prcu_barrier().
>>
>> This is an experimental patch, so it would be good to have some feedback.
>>
>> Known shortcoming is that the grace-period version is incremented in synchronize_prcu().
>> If call_prcu() or prcu_barrier() is called but there is no synchronized_prcu() invoked,
>> callbacks cannot be invoked. Later version should address this issue, e.g. adding a
>> grace-period expedition mechanism. Others include to use a a hierarchical structure,
>> taking into account the NUMA topology, to send IPI in synchronize_prcu().
>>
>> We have tested the implementation using rcutorture on both an x86 and ARM64 machine.
>> PRCU passed 1h and 3h tests on all the newly added config files except PRCU07 reported BUG
>> in a 1h run.
>>
>> [ 1593.604201] ---[ end trace b3bae911bec86152 ]---
>> [ 1594.629450] prcu-torture:torture_onoff task: offlining 14
>> [ 1594.755553] smpboot: CPU 14 is now offline
>> [ 1594.757732] prcu-torture:torture_onoff task: offlined 14
>> [ 1597.765149] prcu-torture:torture_onoff task: onlining 11
>> [ 1597.766795] smpboot: Booting Node 0 Processor 11 APIC 0xb
>> [ 1597.804102] prcu-torture:torture_onoff task: onlined 11
>> [ 1599.365098] prcu-torture: rtc: ffffffffb0277b90 ver: 66358 tfle: 0 rta: 66358 rtaf: 0
>> rtf: 66349 rtmbe: 0 rtbe: 1 rtbke: 0 rtbre: 0 rtbf: 0 rtb: 0 nt: 2233418
>> onoff: 191/191:199/199 34,199:59,5102 10403:0 (HZ=1000) barrier: 188/189:1 cbflood: 225
>> [ 1599.367946] prcu-torture: !!!
>> [ 1599.367966] ------------[ cut here ]------------
>
> The "rtbe: 1" indicates that your implementation of prcu_barrier()
> failed to wait for all preceding call_prcu() callbacks to be invoked.
>
> Does the immediately following "Reader Pipe:" list have any but the
> first two numbers non-zero?
>
Yes.
>> We have also compared PRCU with TREE RCU using rcuperf with gp_exp set to true, that is
>> synchronize_rcu_expedited was tested.
>>
>> The rcuperf results are as follows (average grace-period duration in ms of ten 10min runs):
>>
>> 16*Intel Xeon CPU@xxxxxx, 16GB memory, Ubuntu Linux 3.13.0-47-generic
>>
>> CPUs 2 4 8 12 15 16
>> PRCU 0.14 1.07 4.15 8.02 10.79 15.16
>> TREE 49.30 104.75 277.55 390.82 620.82 1381.54
>>
>> 64*Cortex-A72 CPU@xxxxxx, 130GB memory, Ubuntu Linux 4.10.0-21.23-generic
>>
>> CPUs 2 4 8 16 32 48 63 64
>> PRCU 0.23 19.69 38.28 63.21 95.41 167.18 252.01 1841.44
>> TREE 416.73 901.89 1060.86 743.00 920.66 1325.21 1646.20 23806.27
>
> Well, at the very least, this is a bug report on either expedited RCU
> grace-period latency or on rcuperf's measurements, and thank you for that.
> I will look into this. In the meantime, could you please let me know
> exactly how you invoked rcuperf?
>
We used the following command to invoke rcuperf:
sudo ./kvm.sh --torture rcuperf --duration 10 --configs 10*TREE
The actual script run-rcuperf.sh to run the experiments can be found
in the following email of this patch series:
[PATCH RFC 15/16] rcutorture: Add scripts to run experiments
Please let us know how it goes.
Many thanks,
Lihao.
> I have a few comments on some of your patches based on a quick scan
> through them.
>
> Thanx, Paul
>
>> Best wishes,
>> Lihao.
>>
>>
>> Lihao Liang (15):
>> rcutorture: Add PRCU rcu_torture_ops
>> rcutorture: Add PRCU test config files
>> rcuperf: Add PRCU rcu_perf_ops
>> rcuperf: Add PRCU test config files
>> rcuperf: Set gp_exp to true for tests to run
>> prcu: Implement call_prcu() API
>> prcu: Implement PRCU callback processing
>> prcu: Implement prcu_barrier() API
>> rcutorture: Test call_prcu() and prcu_barrier()
>> rcutorture: Add basic ARM64 support to run scripts
>> prcu: Add PRCU Kconfig parameter
>> prcu: Comment source code
>> rcuperf: Add config files with various CONFIG_NR_CPUS
>> rcutorture: Add scripts to run experiments
>> Add GPLv2 license
>>
>> Heng Zhang (1):
>> prcu: Add PRCU implementation
>>
>> include/linux/interrupt.h | 3 +
>> include/linux/prcu.h | 122 +++++
>> include/linux/rcupdate.h | 1 +
>> init/Kconfig | 7 +
>> init/main.c | 2 +
>> kernel/rcu/Makefile | 1 +
>> kernel/rcu/prcu.c | 497 +++++++++++++++++++++
>> kernel/rcu/rcuperf.c | 33 +-
>> kernel/rcu/rcutorture.c | 40 +-
>> kernel/rcu/tree.c | 1 +
>> kernel/sched/core.c | 2 +
>> kernel/time/timer.c | 2 +
>> kvm.sh | 452 +++++++++++++++++++
>> run-rcuperf.sh | 26 ++
>> .../testing/selftests/rcutorture/bin/functions.sh | 17 +-
>> .../selftests/rcutorture/configs/rcu/CFLIST | 5 +
>> .../selftests/rcutorture/configs/rcu/PRCU02 | 27 ++
>> .../selftests/rcutorture/configs/rcu/PRCU02.boot | 1 +
>> .../selftests/rcutorture/configs/rcu/PRCU03 | 23 +
>> .../selftests/rcutorture/configs/rcu/PRCU03.boot | 2 +
>> .../selftests/rcutorture/configs/rcu/PRCU06 | 26 ++
>> .../selftests/rcutorture/configs/rcu/PRCU06.boot | 5 +
>> .../selftests/rcutorture/configs/rcu/PRCU07 | 25 ++
>> .../selftests/rcutorture/configs/rcu/PRCU07.boot | 2 +
>> .../selftests/rcutorture/configs/rcu/PRCU09 | 19 +
>> .../selftests/rcutorture/configs/rcu/PRCU09.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/CFLIST | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU | 20 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-12 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-12.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-14 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-14.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-15 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-15.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-16 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-16.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-2 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-2.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-32 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-32.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-4 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-4.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-48 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-48.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-56 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-56.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-60 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-60.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-62 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-62.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-64 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-64.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU-8 | 21 +
>> .../rcutorture/configs/rcuperf/PRCU-8.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/PRCU.boot | 1 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-12 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-14 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-15 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-16 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-2 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-32 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-4 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-48 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-56 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-60 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-62 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-64 | 21 +
>> .../selftests/rcutorture/configs/rcuperf/TREE-8 | 21 +
>> 68 files changed, 1918 insertions(+), 5 deletions(-)
>> create mode 100644 include/linux/prcu.h
>> create mode 100644 kernel/rcu/prcu.c
>> create mode 100755 kvm.sh
>> create mode 100755 run-rcuperf.sh
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU02
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU02.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU03
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU03.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU06
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU06.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU07
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU07.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU09
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/PRCU09.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-12
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-12.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-14
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-14.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-15
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-15.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-16
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-16.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-2
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-2.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-32
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-32.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-4
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-4.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-48
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-48.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-56
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-56.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-60
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-60.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-62
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-62.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-64
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-64.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-8
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU-8.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/PRCU.boot
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-12
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-14
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-15
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-16
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-2
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-32
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-4
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-48
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-56
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-60
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-62
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-64
>> create mode 100644 tools/testing/selftests/rcutorture/configs/rcuperf/TREE-8
>>
>> --
>> 2.14.1.729.g59c0ea183
>>
>