Messages in this thread | | | Date | Wed, 24 Jan 2018 21:53:56 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH RFC 00/16] A new RCU implementation based on a fast consensus protocol |
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On Tue, Jan 23, 2018 at 03:59:25PM +0800, lianglihao@huawei.com wrote: > From: Lihao Liang <lianglihao@huawei.com> > > 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?
> 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@2.4GHz, 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@2.4GHz, 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?
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 >
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