| Message ID | 20231212022749.625238-14-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bitops: add atomic find_bit() operations | expand |
On Mon, Dec 11, 2023, Yury Norov wrote: > The function traverses stimer_pending_bitmap in a for-loop bit by bit. > Simplify it by using atomic find_and_set_bit(). for_each_test_and_clear_bit(), not find_and_set_bit(). It might also be nice to call out that there are only 4 bits, i.e. that using for_each_test_and_clear_bit() will still generate inline code. Definitely not mandatory though, just nice to have (I highly doubt this code would be sensitive to using less optimal code). > While here, refactor the logic by decreasing indentation level. > > CC: Sean Christopherson <seanjc@google.com> > Signed-off-by: Yury Norov <yury.norov@gmail.com> > Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > arch/x86/kvm/hyperv.c | 40 ++++++++++++++++++++-------------------- This doesn't conflict with any of the in-flight Hyper-V changes, so with a fixed changelog, feel free to take this through the bitmap tree. Acked-by: Sean Christopherson <seanjc@google.com>
On Tue, Dec 12, 2023 at 09:22:36AM -0800, Sean Christopherson wrote: > On Mon, Dec 11, 2023, Yury Norov wrote: > > The function traverses stimer_pending_bitmap in a for-loop bit by bit. > > Simplify it by using atomic find_and_set_bit(). > > for_each_test_and_clear_bit(), not find_and_set_bit(). > > It might also be nice to call out that there are only 4 bits, i.e. that using > for_each_test_and_clear_bit() will still generate inline code. Definitely not > mandatory though, just nice to have (I highly doubt this code would be sensitive > to using less optimal code). Sure, will do. > > While here, refactor the logic by decreasing indentation level. > > > > CC: Sean Christopherson <seanjc@google.com> > > Signed-off-by: Yury Norov <yury.norov@gmail.com> > > Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> > > --- > > arch/x86/kvm/hyperv.c | 40 ++++++++++++++++++++-------------------- > > This doesn't conflict with any of the in-flight Hyper-V changes, so with a fixed > changelog, feel free to take this through the bitmap tree. > > Acked-by: Sean Christopherson <seanjc@google.com> Thank you!
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 238afd7335e4..d541524ca49f 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -870,27 +870,27 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu) if (!hv_vcpu) return; - for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++) - if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) { - stimer = &hv_vcpu->stimer[i]; - if (stimer->config.enable) { - exp_time = stimer->exp_time; - - if (exp_time) { - time_now = - get_time_ref_counter(vcpu->kvm); - if (time_now >= exp_time) - stimer_expiration(stimer); - } - - if ((stimer->config.enable) && - stimer->count) { - if (!stimer->msg_pending) - stimer_start(stimer); - } else - stimer_cleanup(stimer); - } + for_each_test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap, + ARRAY_SIZE(hv_vcpu->stimer)) { + stimer = &hv_vcpu->stimer[i]; + if (!stimer->config.enable) + continue; + + exp_time = stimer->exp_time; + + if (exp_time) { + time_now = get_time_ref_counter(vcpu->kvm); + if (time_now >= exp_time) + stimer_expiration(stimer); } + + if (stimer->config.enable && stimer->count) { + if (!stimer->msg_pending) + stimer_start(stimer); + } else { + stimer_cleanup(stimer); + } + } } void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)