search for: queue_spinlocks

Il 26/02/2014 16:14, Waiman Long ha scritto: > This patch enables KVM to use the queue spinlock's PV support code > when the PARAVIRT_SPINLOCKS kernel config option is set. However, > PV support for Xen is not ready yet and so the queue spinlock will > still have to be disabled when PARAVIRT_SPINLOCKS config option is > on with Xen. > > Signed-off-by: Waiman Long

Il 26/02/2014 16:14, Waiman Long ha scritto: > This patch enables KVM to use the queue spinlock's PV support code > when the PARAVIRT_SPINLOCKS kernel config option is set. However, > PV support for Xen is not ready yet and so the queue spinlock will > still have to be disabled when PARAVIRT_SPINLOCKS config option is > on with Xen. > > Signed-off-by: Waiman Long

> Raghavendra KT had done some performance testing on this patch with > the following results: > > Overall we are seeing good improvement for pv-unfair version. > > System: 32 cpu sandybridge with HT on (4 node with 32 GB each) > Guest : 8GB with 16 vcpu/VM. > Average was taken over 8-10 data points. > > Base = 3.15-rc2 with PRAVIRT_SPINLOCK = y > > A =

> Raghavendra KT had done some performance testing on this patch with > the following results: > > Overall we are seeing good improvement for pv-unfair version. > > System: 32 cpu sandybridge with HT on (4 node with 32 GB each) > Guest : 8GB with 16 vcpu/VM. > Average was taken over 8-10 data points. > > Base = 3.15-rc2 with PRAVIRT_SPINLOCK = y > > A =

Signed-off-by: Peter Zijlstra <peterz at infradead.org> --- arch/x86/kernel/kvm.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/Kconfig.locks | 2 - 2 files changed, 59 insertions(+), 1 deletion(-) Index: linux-2.6/arch/x86/kernel/kvm.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/kvm.c +++

This patch adds the necessary KVM specific code to allow KVM to support the CPU halting and kicking operations needed by the queue spinlock PV code. Two KVM guests of 20 CPU cores (2 nodes) were created for performance testing in one of the following three configurations: 1) Only 1 VM is active 2) Both VMs are active and they share the same 20 physical CPUs (200% overcommit) 3) Both VMs are

On 04/17/2014 08:33 PM, Waiman Long wrote: > v8->v9: > - Integrate PeterZ's version of the queue spinlock patch with some > modification: > http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org > - Break the more complex patches into smaller ones to ease review effort. > - Fix a racing condition in the PV qspinlock code. > > v7->v8:

> diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks > index a70fdeb..451e392 100644 > --- a/kernel/Kconfig.locks > +++ b/kernel/Kconfig.locks > @@ -229,4 +229,4 @@ config ARCH_USE_QUEUE_SPINLOCK > > config QUEUE_SPINLOCK > def_bool y if ARCH_USE_QUEUE_SPINLOCK > - depends on SMP && (!PARAVIRT_SPINLOCKS || !XEN) > + depends on SMP If I read this

...r Zijlstra wrote: > > I feel that if someone were to do a Xen patch we can go ahead and merge this > stuff (finally!). This seems work for me, but I've not got time to give it a more thorough testing. You can fold this into your series. There doesn't seem to be a way to disable QUEUE_SPINLOCKS when supported by the arch, is this intentional? If so, the existing ticketlock code could go. David 8<------------------------------ x86/xen: paravirt support for qspinlocks Provide the wait and kick ops necessary for paravirt-aware queue spinlocks. Signed-off-by: David Vrabel <david.vr...

> diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks > index a70fdeb..451e392 100644 > --- a/kernel/Kconfig.locks > +++ b/kernel/Kconfig.locks > @@ -229,4 +229,4 @@ config ARCH_USE_QUEUE_SPINLOCK > > config QUEUE_SPINLOCK > def_bool y if ARCH_USE_QUEUE_SPINLOCK > - depends on SMP && (!PARAVIRT_SPINLOCKS || !XEN) > + depends on SMP If I read this

...r Zijlstra wrote: > > I feel that if someone were to do a Xen patch we can go ahead and merge this > stuff (finally!). This seems work for me, but I've not got time to give it a more thorough testing. You can fold this into your series. There doesn't seem to be a way to disable QUEUE_SPINLOCKS when supported by the arch, is this intentional? If so, the existing ticketlock code could go. David 8<------------------------------ x86/xen: paravirt support for qspinlocks Provide the wait and kick ops necessary for paravirt-aware queue spinlocks. Signed-off-by: David Vrabel <david.vr...

...l/paravirt_patch_32.c +++ b/arch/x86/kernel/paravirt_patch_32.c @@ -12,6 +12,10 @@ DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %c DEF_NATIVE(pv_cpu_ops, clts, "clts"); DEF_NATIVE(pv_cpu_ops, read_tsc, "rdtsc"); +#if defined(CONFIG_PARAVIRT_SPINLOCKS) && defined(CONFIG_QUEUE_SPINLOCKS) +DEF_NATIVE(pv_lock_ops, queue_spin_unlock, "movb $0, (%eax)"); +#endif + unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len) { /* arg in %eax, return in %eax */ @@ -24,6 +28,8 @@ unsigned paravirt_patch_ident_64(void *i return 0; } +extern bool pv_is_native_spin_unloc...

...l/paravirt_patch_32.c +++ b/arch/x86/kernel/paravirt_patch_32.c @@ -12,6 +12,10 @@ DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %c DEF_NATIVE(pv_cpu_ops, clts, "clts"); DEF_NATIVE(pv_cpu_ops, read_tsc, "rdtsc"); +#if defined(CONFIG_PARAVIRT_SPINLOCKS) && defined(CONFIG_QUEUE_SPINLOCKS) +DEF_NATIVE(pv_lock_ops, queue_spin_unlock, "movb $0, (%eax)"); +#endif + unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len) { /* arg in %eax, return in %eax */ @@ -24,6 +28,8 @@ unsigned paravirt_patch_ident_64(void *i return 0; } +extern bool pv_is_native_spin_unloc...

This patch enables KVM to use the queue spinlock's PV support code when the PARAVIRT_SPINLOCKS kernel config option is set. However, PV support for Xen is not ready yet and so the queue spinlock will still have to be disabled when PARAVIRT_SPINLOCKS config option is on with Xen. Signed-off-by: Waiman Long <Waiman.Long at hp.com> --- arch/x86/kernel/kvm.c | 54

This patch adds the necessary Xen specific code to allow Xen to support the CPU halting and kicking operations needed by the queue spinlock PV code. Signed-off-by: Waiman Long <Waiman.Long at hp.com> --- arch/x86/xen/spinlock.c | 63 ++++++++++++++++++++++++++++++++++++++++++++--- kernel/Kconfig.locks | 2 +- 2 files changed, 60 insertions(+), 5 deletions(-) diff --git

On 06/15/2014 06:17 PM, Peter Zijlstra wrote: > Signed-off-by: Peter Zijlstra<peterz at infradead.org> > --- [...] > + > +void kvm_wait(int *ptr, int val) > +{ > + unsigned long flags; > + > + if (in_nmi()) > + return; > + > + /* > + * Make sure an interrupt handler can't upset things in a > + * partially setup state. > + */ I am seeing hang

On 06/15/2014 06:17 PM, Peter Zijlstra wrote: > Signed-off-by: Peter Zijlstra<peterz at infradead.org> > --- [...] > + > +void kvm_wait(int *ptr, int val) > +{ > + unsigned long flags; > + > + if (in_nmi()) > + return; > + > + /* > + * Make sure an interrupt handler can't upset things in a > + * partially setup state. > + */ I am seeing hang

This patch adds the necessary KVM specific code to allow KVM to support the sleeping and CPU kicking operations needed by the queue spinlock PV code. A KVM guest of 20 CPU cores was created to run the disk workload of the AIM7 benchmark on both ext4 and xfs RAM disks at 3000 users on a 3.14-rc6 based kernel. The JPM (jobs/minute) data of the test run were: kernel XFS FS

This patch adds the necessary KVM specific code to allow XEN to support the sleeping and CPU kicking operations needed by the queue spinlock PV code. Signed-off-by: Waiman Long <Waiman.Long at hp.com> --- arch/x86/xen/spinlock.c | 119 +++++++++++++++++++++++++++++++++++++++++++++-- kernel/Kconfig.locks | 2 +- 2 files changed, 115 insertions(+), 6 deletions(-) diff --git

This patch adds the necessary XEN specific code to allow XEN to support the CPU halting and kicking operations needed by the queue spinlock PV code. Signed-off-by: Waiman Long <Waiman.Long at hp.com> --- arch/x86/xen/spinlock.c | 149 +++++++++++++++++++++++++++++++++++++++++++++-- kernel/Kconfig.locks | 2 +- 2 files changed, 145 insertions(+), 6 deletions(-) diff --git