On Sun, Sep 10, 2023 at 04:28:54AM -0400, guoren@xxxxxxxxxx wrote: > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > patch[1 - 10]: Native qspinlock > patch[11 -17]: Paravirt qspinlock > > patch[4]: Add prefetchw in qspinlock's xchg_tail when cpus >= 16k > > This series based on: > - [RFC PATCH v5 0/5] Rework & improve riscv cmpxchg.h and atomic.h > https://lore.kernel.org/linux-riscv/20230810040349.92279-2-leobras@xxxxxxxxxx/ > - [PATCH V3] asm-generic: ticket-lock: Optimize arch_spin_value_unlocked > https://lore.kernel.org/linux-riscv/20230908154339.3250567-1-guoren@xxxxxxxxxx/ > > I merge them into sg2042-master branch, then you could directly try it on > sg2042 hardware platform: > > https://github.com/guoren83/linux/tree/sg2042-master-qspinlock-64ilp32_v5 > > Use sophgo_mango_ubuntu_defconfig for sg2042 64/128 cores hardware > platform. > > Native qspinlock > ================ > > This time we've proved the qspinlock on th1520 [1] & sg2042 [2], which > gives stability and performance improvement. All T-HEAD processors have > a strong LR/SC forward progress guarantee than the requirements of the > ISA, which could satisfy the xchg_tail of native_qspinlock. Now, > qspinlock has been run with us for more than 1 year, and we have enough > confidence to enable it for all the T-HEAD processors. Of causes, we > found a livelock problem with the qspinlock lock torture test from the > CPU store merge buffer delay mechanism, which caused the queued spinlock > becomes a dead ring and RCU warning to come out. We introduce a custom > WRITE_ONCE to solve this. Do we need explicit ISA instruction to signal > it? Or let hardware handle this. > > We've tested the patch on SOPHGO sg2042 & th1520 and passed the stress > test on Fedora & Ubuntu & OpenEuler ... Here is the performance > comparison between qspinlock and ticket_lock on sg2042 (64 cores): > > sysbench test=threads threads=32 yields=100 lock=8 (+13.8%): > queued_spinlock 0.5109/0.00 > ticket_spinlock 0.5814/0.00 > > perf futex/hash (+6.7%): > queued_spinlock 1444393 operations/sec (+- 0.09%) > ticket_spinlock 1353215 operations/sec (+- 0.15%) > > perf futex/wake-parallel (+8.6%): > queued_spinlock (waking 1/64 threads) in 0.0253 ms (+-2.90%) > ticket_spinlock (waking 1/64 threads) in 0.0275 ms (+-3.12%) > > perf futex/requeue (+4.2%): > queued_spinlock Requeued 64 of 64 threads in 0.0785 ms (+-0.55%) > ticket_spinlock Requeued 64 of 64 threads in 0.0818 ms (+-4.12%) > > System Benchmarks (+6.4%) > queued_spinlock: > System Benchmarks Index Values BASELINE RESULT INDEX > Dhrystone 2 using register variables 116700.0 628613745.4 53865.8 > Double-Precision Whetstone 55.0 182422.8 33167.8 > Execl Throughput 43.0 13116.6 3050.4 > File Copy 1024 bufsize 2000 maxblocks 3960.0 7762306.2 19601.8 > File Copy 256 bufsize 500 maxblocks 1655.0 3417556.8 20649.9 > File Copy 4096 bufsize 8000 maxblocks 5800.0 7427995.7 12806.9 > Pipe Throughput 12440.0 23058600.5 18535.9 > Pipe-based Context Switching 4000.0 2835617.7 7089.0 > Process Creation 126.0 12537.3 995.0 > Shell Scripts (1 concurrent) 42.4 57057.4 13456.9 > Shell Scripts (8 concurrent) 6.0 7367.1 12278.5 > System Call Overhead 15000.0 33308301.3 22205.5 > ======== > System Benchmarks Index Score 12426.1 > > ticket_spinlock: > System Benchmarks Index Values BASELINE RESULT INDEX > Dhrystone 2 using register variables 116700.0 626541701.9 53688.2 > Double-Precision Whetstone 55.0 181921.0 33076.5 > Execl Throughput 43.0 12625.1 2936.1 > File Copy 1024 bufsize 2000 maxblocks 3960.0 6553792.9 16550.0 > File Copy 256 bufsize 500 maxblocks 1655.0 3189231.6 19270.3 > File Copy 4096 bufsize 8000 maxblocks 5800.0 7221277.0 12450.5 > Pipe Throughput 12440.0 20594018.7 16554.7 > Pipe-based Context Switching 4000.0 2571117.7 6427.8 > Process Creation 126.0 10798.4 857.0 > Shell Scripts (1 concurrent) 42.4 57227.5 13497.1 > Shell Scripts (8 concurrent) 6.0 7329.2 12215.3 > System Call Overhead 15000.0 30766778.4 20511.2 > ======== > System Benchmarks Index Score 11670.7 > > The qspinlock has a significant improvement on SOPHGO SG2042 64 > cores platform than the ticket_lock. > > Paravirt qspinlock > ================== > > We implemented kvm_kick_cpu/kvm_wait_cpu and add tracepoints to observe the > behaviors. Also, introduce a new SBI extension SBI_EXT_PVLOCK (0xAB0401). If the > name and number are approved, I will send a formal proposal to the SBI spec. > Hello Guo Ren, Any update on this series? Thanks! Leo > Changlog: > V11: > - Based on Leonardo Bras's cmpxchg_small patches v5. > - Based on Guo Ren's Optimize arch_spin_value_unlocked patch v3. > - Remove abusing alternative framework and use jump_label instead. > - Introduce prefetch.w to improve T-HEAD processors' LR/SC forward progress > guarantee. > - Optimize qspinlock xchg_tail when NR_CPUS >= 16K. > > V10: > https://lore.kernel.org/linux-riscv/20230802164701.192791-1-guoren@xxxxxxxxxx/ > - Using an alternative framework instead of static_key_branch in the > asm/spinlock.h. > - Fixup store merge buffer problem, which causes qspinlock lock > torture test livelock. > - Add paravirt qspinlock support, include KVM backend > - Add Compact NUMA-awared qspinlock support > > V9: > https://lore.kernel.org/linux-riscv/20220808071318.3335746-1-guoren@xxxxxxxxxx/ > - Cleanup generic ticket-lock code, (Using smp_mb__after_spinlock as > RCsc) > - Add qspinlock and combo-lock for riscv > - Add qspinlock to openrisc > - Use generic header in csky > - Optimize cmpxchg & atomic code > > V8: > https://lore.kernel.org/linux-riscv/20220724122517.1019187-1-guoren@xxxxxxxxxx/ > - Coding convention ticket fixup > - Move combo spinlock into riscv and simply asm-generic/spinlock.h > - Fixup xchg16 with wrong return value > - Add csky qspinlock > - Add combo & qspinlock & ticket-lock comparison > - Clean up unnecessary riscv acquire and release definitions > - Enable ARCH_INLINE_READ*/WRITE*/SPIN* for riscv & csky > > V7: > https://lore.kernel.org/linux-riscv/20220628081946.1999419-1-guoren@xxxxxxxxxx/ > - Add combo spinlock (ticket & queued) support > - Rename ticket_spinlock.h > - Remove unnecessary atomic_read in ticket_spin_value_unlocked > > V6: > https://lore.kernel.org/linux-riscv/20220621144920.2945595-1-guoren@xxxxxxxxxx/ > - Fixup Clang compile problem Reported-by: kernel test robot > - Cleanup asm-generic/spinlock.h > - Remove changelog in patch main comment part, suggested by > Conor.Dooley > - Remove "default y if NUMA" in Kconfig > > V5: > https://lore.kernel.org/linux-riscv/20220620155404.1968739-1-guoren@xxxxxxxxxx/ > - Update comment with RISC-V forward guarantee feature. > - Back to V3 direction and optimize asm code. > > V4: > https://lore.kernel.org/linux-riscv/1616868399-82848-4-git-send-email-guoren@xxxxxxxxxx/ > - Remove custom sub-word xchg implementation > - Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32 in locking/qspinlock > > V3: > https://lore.kernel.org/linux-riscv/1616658937-82063-1-git-send-email-guoren@xxxxxxxxxx/ > - Coding convention by Peter Zijlstra's advices > > V2: > https://lore.kernel.org/linux-riscv/1606225437-22948-2-git-send-email-guoren@xxxxxxxxxx/ > - Coding convention in cmpxchg.h > - Re-implement short xchg > - Remove char & cmpxchg implementations > > V1: > https://lore.kernel.org/linux-riscv/20190211043829.30096-1-michaeljclark@xxxxxxx/ > - Using cmpxchg loop to implement sub-word atomic > > > Guo Ren (17): > asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock > asm-generic: ticket-lock: Move into ticket_spinlock.h > riscv: Use Zicbop in arch_xchg when available > locking/qspinlock: Improve xchg_tail for number of cpus >= 16k > riscv: qspinlock: Add basic queued_spinlock support > riscv: qspinlock: Introduce combo spinlock > riscv: qspinlock: Introduce qspinlock param for command line > riscv: qspinlock: Add virt_spin_lock() support for KVM guest > riscv: qspinlock: errata: Add ERRATA_THEAD_WRITE_ONCE fixup > riscv: qspinlock: errata: Enable qspinlock for T-HEAD processors > RISC-V: paravirt: pvqspinlock: Add paravirt qspinlock skeleton > RISC-V: paravirt: pvqspinlock: Add nopvspin kernel parameter > RISC-V: paravirt: pvqspinlock: Add SBI implementation > RISC-V: paravirt: pvqspinlock: Add kconfig entry > RISC-V: paravirt: pvqspinlock: Add trace point for pv_kick/wait > RISC-V: paravirt: pvqspinlock: KVM: Add paravirt qspinlock skeleton > RISC-V: paravirt: pvqspinlock: KVM: Implement > kvm_sbi_ext_pvlock_kick_cpu() > > .../admin-guide/kernel-parameters.txt | 8 +- > arch/riscv/Kconfig | 50 ++++++++ > arch/riscv/Kconfig.errata | 19 +++ > arch/riscv/errata/thead/errata.c | 29 +++++ > arch/riscv/include/asm/Kbuild | 2 +- > arch/riscv/include/asm/cmpxchg.h | 4 +- > arch/riscv/include/asm/errata_list.h | 13 -- > arch/riscv/include/asm/hwcap.h | 1 + > arch/riscv/include/asm/insn-def.h | 5 + > arch/riscv/include/asm/kvm_vcpu_sbi.h | 1 + > arch/riscv/include/asm/processor.h | 13 ++ > arch/riscv/include/asm/qspinlock.h | 35 ++++++ > arch/riscv/include/asm/qspinlock_paravirt.h | 29 +++++ > arch/riscv/include/asm/rwonce.h | 24 ++++ > arch/riscv/include/asm/sbi.h | 14 +++ > arch/riscv/include/asm/spinlock.h | 113 ++++++++++++++++++ > arch/riscv/include/asm/vendorid_list.h | 14 +++ > arch/riscv/include/uapi/asm/kvm.h | 1 + > arch/riscv/kernel/Makefile | 1 + > arch/riscv/kernel/cpufeature.c | 1 + > arch/riscv/kernel/qspinlock_paravirt.c | 83 +++++++++++++ > arch/riscv/kernel/sbi.c | 2 +- > arch/riscv/kernel/setup.c | 60 ++++++++++ > .../kernel/trace_events_filter_paravirt.h | 60 ++++++++++ > arch/riscv/kvm/Makefile | 1 + > arch/riscv/kvm/vcpu_sbi.c | 4 + > arch/riscv/kvm/vcpu_sbi_pvlock.c | 57 +++++++++ > include/asm-generic/rwonce.h | 2 + > include/asm-generic/spinlock.h | 87 +------------- > include/asm-generic/spinlock_types.h | 12 +- > include/asm-generic/ticket_spinlock.h | 103 ++++++++++++++++ > kernel/locking/qspinlock.c | 5 +- > 32 files changed, 739 insertions(+), 114 deletions(-) > create mode 100644 arch/riscv/include/asm/qspinlock.h > create mode 100644 arch/riscv/include/asm/qspinlock_paravirt.h > create mode 100644 arch/riscv/include/asm/rwonce.h > create mode 100644 arch/riscv/include/asm/spinlock.h > create mode 100644 arch/riscv/kernel/qspinlock_paravirt.c > create mode 100644 arch/riscv/kernel/trace_events_filter_paravirt.h > create mode 100644 arch/riscv/kvm/vcpu_sbi_pvlock.c > create mode 100644 include/asm-generic/ticket_spinlock.h > > -- > 2.36.1 >
