Changes from v1: https://lkml.org/lkml/2017/9/5/622 - Added patch 7 (mips) - Small comment fixlets in patch 1. Hi, Recently[1] Nick mentioned that a lot of swait_active() callers look fishy. This is because it inherited bad habits from regular waitqueues. Other than rcu, kvm is one of the main callers, which I audited. The following patches fix and/or justify (in baby steps) some of the callers. The main exception is s390, which I didn't follow how ->valid_wakeup can get hoisted as kvm_vcpu_block does not use that in the wait loop. Thanks! Davidlohr Bueso (7): sched/wait: Add swq_has_sleepers() kvm,async_pf: Use swq_has_sleepers() kvm,lapic: Justify use of swait_activate() kvm,x86: Fix apf_task_wake_one() wq serialization kvm: Serialize wq active checks in kvm_vcpu_wake_up() kvm,powerpc: Serialize wq active checks in ops->vcpu_kick kvm,mips: Fix potential swait_active() races arch/mips/kvm/mips.c | 4 +-- arch/powerpc/kvm/book3s_hv.c | 2 +- arch/x86/kernel/kvm.c | 2 +- arch/x86/kvm/lapic.c | 4 +++ include/linux/swait.h | 58 ++++++++++++++++++++++++++++++++++++++++++-- virt/kvm/async_pf.c | 6 +---- virt/kvm/kvm_main.c | 2 +- 7 files changed, 66 insertions(+), 12 deletions(-) -- 2.12.0
