leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: s390: count invalid yields

Browse Source 
To analyze some performance issues with lock contention and scheduling
it is nice to know when diag9c did not result in any action or when
no action was tried.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
This commit is contained in:
Christian Borntraeger 2019-02-15 13:47:20 +01:00
parent efec8d219f
commit 8474e5cac0
3 changed files with 16 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/s390/include/asm/kvm_host.h
View File

@ -392,6 +392,7 @@ struct kvm_vcpu_stat {
u64 diagnose_10;
u64 diagnose_44;
u64 diagnose_9c;
u64 diagnose_9c_ignored;
u64 diagnose_258;
u64 diagnose_308;
u64 diagnose_500;

18
arch/s390/kvm/diag.c
View File

@ -158,14 +158,24 @@ static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
vcpu->stat.diagnose_9c++;
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
/* yield to self */
if (tid == vcpu->vcpu_id)
return 0;
goto no_yield;
/* yield to invalid */
tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
if (tcpu)
kvm_vcpu_yield_to(tcpu);
if (!tcpu)
goto no_yield;
if (kvm_vcpu_yield_to(tcpu) <= 0)
goto no_yield;
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid);
return 0;
no_yield:
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid);
vcpu->stat.diagnose_9c_ignored++;
return 0;
}

1
arch/s390/kvm/kvm-s390.c
View File

@ -155,6 +155,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "instruction_diag_10", VCPU_STAT(diagnose_10) },
{ "instruction_diag_44", VCPU_STAT(diagnose_44) },
{ "instruction_diag_9c", VCPU_STAT(diagnose_9c) },
{ "diag_9c_ignored", VCPU_STAT(diagnose_9c_ignored) },
{ "instruction_diag_258", VCPU_STAT(diagnose_258) },
{ "instruction_diag_308", VCPU_STAT(diagnose_308) },
{ "instruction_diag_500", VCPU_STAT(diagnose_500) },