From 1b6766c7f3533c5d03668e11dd5617ae4a52e5a8 Mon Sep 17 00:00:00 2001 From: Hollis Blanchard Date: Wed, 5 Nov 2008 09:36:21 -0600 Subject: [PATCH] KVM: ppc: optimize kvm stat handling Currently we use an unnecessary if&switch to detect some cases. To be honest we don't need the ligh_exits counter anyway, because we can calculate it out of others. Sum_exits can also be calculated, so we can remove that too. MMIO, DCR and INTR can be counted on other places without these additional control structures (The INTR case was never hit anyway). The handling of BOOKE_INTERRUPT_EXTERNAL/BOOKE_INTERRUPT_DECREMENTER is similar, but we can avoid the additional if when copying 3 lines of code. I thought about a goto there to prevent duplicate lines, but rewriting three lines should be better style than a goto cross switch/case statements (its also not enough code to justify a new inline function). Signed-off-by: Christian Ehrhardt Signed-off-by: Hollis Blanchard Signed-off-by: Avi Kivity --- arch/powerpc/kvm/booke.c | 32 +++++++++----------------------- 1 file changed, 9 insertions(+), 23 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index dec3f50a494f..b285e3d32466 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -38,11 +38,9 @@ unsigned long kvmppc_booke_handlers; #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU struct kvm_stats_debugfs_item debugfs_entries[] = { - { "exits", VCPU_STAT(sum_exits) }, { "mmio", VCPU_STAT(mmio_exits) }, { "dcr", VCPU_STAT(dcr_exits) }, { "sig", VCPU_STAT(signal_exits) }, - { "light", VCPU_STAT(light_exits) }, { "itlb_r", VCPU_STAT(itlb_real_miss_exits) }, { "itlb_v", VCPU_STAT(itlb_virt_miss_exits) }, { "dtlb_r", VCPU_STAT(dtlb_real_miss_exits) }, @@ -263,6 +261,12 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, break; case BOOKE_INTERRUPT_EXTERNAL: + vcpu->stat.ext_intr_exits++; + if (need_resched()) + cond_resched(); + r = RESUME_GUEST; + break; + case BOOKE_INTERRUPT_DECREMENTER: /* Since we switched IVPR back to the host's value, the host * handled this interrupt the moment we enabled interrupts. @@ -272,12 +276,9 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, * we do reschedule the host will fault over it. Perhaps we * should politely restore the host's entries to minimize * misses before ceding control. */ + vcpu->stat.dec_exits++; if (need_resched()) cond_resched(); - if (exit_nr == BOOKE_INTERRUPT_DECREMENTER) - vcpu->stat.dec_exits++; - else - vcpu->stat.ext_intr_exits++; r = RESUME_GUEST; break; @@ -301,6 +302,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, break; case EMULATE_DO_DCR: run->exit_reason = KVM_EXIT_DCR; + vcpu->stat.dcr_exits++; r = RESUME_HOST; break; case EMULATE_FAIL: @@ -379,6 +381,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, /* Guest has mapped and accessed a page which is not * actually RAM. */ r = kvmppc_emulate_mmio(run, vcpu); + vcpu->stat.mmio_exits++; } break; @@ -445,8 +448,6 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, kvmppc_core_deliver_interrupts(vcpu); - /* Do some exit accounting. */ - vcpu->stat.sum_exits++; if (!(r & RESUME_HOST)) { /* To avoid clobbering exit_reason, only check for signals if * we aren't already exiting to userspace for some other @@ -454,22 +455,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, if (signal_pending(current)) { run->exit_reason = KVM_EXIT_INTR; r = (-EINTR << 2) | RESUME_HOST | (r & RESUME_FLAG_NV); - vcpu->stat.signal_exits++; - } else { - vcpu->stat.light_exits++; - } - } else { - switch (run->exit_reason) { - case KVM_EXIT_MMIO: - vcpu->stat.mmio_exits++; - break; - case KVM_EXIT_DCR: - vcpu->stat.dcr_exits++; - break; - case KVM_EXIT_INTR: - vcpu->stat.signal_exits++; - break; } }