| Message ID | 20121212104821.GA6324@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 2012-12-12 11:48, Michael S. Tsirkin wrote: > Deleting a GSI isn't necessary: it is enough > to stop using it. Delay flush until an entry is used. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > kvm-all.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kvm-all.c b/kvm-all.c > index 3bc3347..fb3180d 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) > } > } > clear_gsi(s, virq); > - > - kvm_irqchip_commit_routes(s); > } > > static unsigned int kvm_hash_msi(uint32_t data) > Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Hello Michael, On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote: > Deleting a GSI isn't necessary: it is enough > to stop using it. Delay flush until an entry is used. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > kvm-all.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kvm-all.c b/kvm-all.c > index 3bc3347..fb3180d 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) > } > } > clear_gsi(s, virq); > - > - kvm_irqchip_commit_routes(s); > } > > static unsigned int kvm_hash_msi(uint32_t data) > I tried this patch with vhost-blk with qemu-1.3.0 6d6c9f59ca1b1a76ade7ad868bef191818f58819. Without the drop of msix_fire_vector_notifier in msix_handle_mask_update hack Before: ~20K IOPS After: ~35K IOPS With the drop of msix_fire_vector_notifier in msix_handle_mask_update hack Before: ~197K IOPS After: ~197K IOPS
On 2012-12-13 05:55, Asias He wrote: > Hello Michael, > > On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote: >> Deleting a GSI isn't necessary: it is enough >> to stop using it. Delay flush until an entry is used. >> >> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> >> --- >> kvm-all.c | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/kvm-all.c b/kvm-all.c >> index 3bc3347..fb3180d 100644 >> --- a/kvm-all.c >> +++ b/kvm-all.c >> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) >> } >> } >> clear_gsi(s, virq); >> - >> - kvm_irqchip_commit_routes(s); >> } >> >> static unsigned int kvm_hash_msi(uint32_t data) >> > > I tried this patch with vhost-blk with qemu-1.3.0 > 6d6c9f59ca1b1a76ade7ad868bef191818f58819. > > Without the drop of msix_fire_vector_notifier in msix_handle_mask_update > hack > Before: ~20K IOPS > After: ~35K IOPS > > With the drop of msix_fire_vector_notifier in > msix_handle_mask_update hack > Before: ~197K IOPS > After: ~197K IOPS > Is the guest balancing the IRQ(s) between its vCPUs all the time? Jan
Hello Jan, On 12/13/2012 11:34 PM, Jan Kiszka wrote: > On 2012-12-13 05:55, Asias He wrote: >> Hello Michael, >> >> On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote: >>> Deleting a GSI isn't necessary: it is enough >>> to stop using it. Delay flush until an entry is used. >>> >>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> >>> --- >>> kvm-all.c | 2 -- >>> 1 file changed, 2 deletions(-) >>> >>> diff --git a/kvm-all.c b/kvm-all.c >>> index 3bc3347..fb3180d 100644 >>> --- a/kvm-all.c >>> +++ b/kvm-all.c >>> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) >>> } >>> } >>> clear_gsi(s, virq); >>> - >>> - kvm_irqchip_commit_routes(s); >>> } >>> >>> static unsigned int kvm_hash_msi(uint32_t data) >>> >> >> I tried this patch with vhost-blk with qemu-1.3.0 >> 6d6c9f59ca1b1a76ade7ad868bef191818f58819. >> >> Without the drop of msix_fire_vector_notifier in msix_handle_mask_update >> hack >> Before: ~20K IOPS >> After: ~35K IOPS >> >> With the drop of msix_fire_vector_notifier in >> msix_handle_mask_update hack >> Before: ~197K IOPS >> After: ~197K IOPS >> > > Is the guest balancing the IRQ(s) between its vCPUs all the time? Yes. In all of the four the cases (w/o gsi patch, w/o drop of msix_fire_vector_notifier hack), IRQs balanced evenly in all vCPUs.
diff --git a/kvm-all.c b/kvm-all.c index 3bc3347..fb3180d 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) } } clear_gsi(s, virq); - - kvm_irqchip_commit_routes(s); } static unsigned int kvm_hash_msi(uint32_t data)
Deleting a GSI isn't necessary: it is enough to stop using it. Delay flush until an entry is used. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- kvm-all.c | 2 -- 1 file changed, 2 deletions(-)