| Message ID | 20250102150201.21639-1-frederic@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | cpuidle: Handle TIF_NR_POLLING on behalf of polling idle states | expand |
Hello Frederic, On 1/2/2025 8:31 PM, Frederic Weisbecker wrote: > The TIF_NR_POLLING handling against TIF_NEED_RESCHED polling/monitoring > idle states (mwait and also software polling) is a bit messy, with quite > some wasted cycles spent on useless atomic operations. This tries to > consolidate this state handling from the cpuidle core. I tested this series on my 3rd Generation EPYC System with ipistorm and I've not observed any regressions in IPI throughput to idle CPUs in TIF_POLLING mode. Additionally tested few microbenchmarks and there were no surprises there either. Feel free to add: Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
The TIF_NR_POLLING handling against TIF_NEED_RESCHED polling/monitoring idle states (mwait and also software polling) is a bit messy, with quite some wasted cycles spent on useless atomic operations. This tries to consolidate this state handling from the cpuidle core. Changes since v2: _ Handle buggy mwait implementations (thanks Rafael) Frederic Weisbecker (4): cpuidle: Remove unnecessary current_clr_polling_and_test() from haltpoll x86/cpuidle: Move buggy mwait implementations away from CPUIDLE_FLAG_MWAIT cpuidle: Remove call_cpuidle_s2idle() cpuidle: Handle TIF_NR_POLLING on behalf of software polling idle states Peter Zijlstra (2): cpuidle: Introduce CPUIDLE_FLAG_MWAIT cpuidle: Handle TIF_NR_POLLING on behalf of CPUIDLE_FLAG_MWAIT states arch/arm/include/asm/cpuidle.h | 2 ++ arch/arm64/include/asm/cpuidle.h | 3 ++ arch/powerpc/include/asm/cpuidle.h | 4 +++ arch/riscv/include/asm/cpuidle.h | 2 ++ arch/x86/include/asm/cpuidle.h | 12 +++++++ arch/x86/include/asm/mwait.h | 27 +++++++-------- drivers/acpi/processor_idle.c | 5 +++ drivers/cpuidle/cpuidle-haltpoll.c | 3 -- drivers/cpuidle/cpuidle-powernv.c | 10 ------ drivers/cpuidle/cpuidle-pseries.c | 11 ------- drivers/cpuidle/cpuidle.c | 22 ++++++++++++- drivers/cpuidle/poll_state.c | 30 +++++++---------- drivers/idle/intel_idle.c | 8 +++++ include/asm-generic/Kbuild | 1 + include/asm-generic/cpuidle.h | 10 ++++++ include/linux/cpuidle.h | 1 + include/linux/sched/idle.h | 7 +++- kernel/sched/idle.c | 53 +++++++++--------------------- 18 files changed, 114 insertions(+), 97 deletions(-) create mode 100644 arch/x86/include/asm/cpuidle.h create mode 100644 include/asm-generic/cpuidle.h