search for: queue_spinlock

...a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index f318e78..3ddc436 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static...

...a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index f318e78..3ddc436 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static...

...g 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 = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y > PRAVIRT_SPINLOCK = y PARAVIRT_UNFAIR_LOCKS = y (unfair lock) > > B = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y > PRAVIRT_SPINLOCK = n PARAVIRT_UNFAIR_LOCKS = n > (queue spinlock without paravirt) > > C = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK =...

...g 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 = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y > PRAVIRT_SPINLOCK = y PARAVIRT_UNFAIR_LOCKS = y (unfair lock) > > B = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y > PRAVIRT_SPINLOCK = n PARAVIRT_UNFAIR_LOCKS = n > (queue spinlock without paravirt) > > C = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK =...

...nux-2.6/arch/x86/kernel/kvm.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/kvm.c +++ linux-2.6/arch/x86/kernel/kvm.c @@ -569,6 +569,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -796,6 +797,51 @@ static void kvm_unlock_kick(struct arch_ } } } +#else /* QUEUE_SPINLOCK */ + +#include <asm-generic/qspinlock.h> + +PV_CALLEE_SAVE_REGS_THUNK(__pv_init_node); +PV_CALLEE_SAVE_REGS_THUNK(__pv_link_and_wai...

...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 = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = y PARAVIRT_UNFAIR_LOCKS = y (unfair lock) B = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = n PARAVIRT_UNFAIR_LOCKS = n (queue spinlock without paravirt) C = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = y PARAVIRT_UN...

...he results: Overall we are seeing good improvement for pv-unfair version. System : 32 cpu sandybridge with HT on. (4 node machine 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 = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = y PARAVIRT_UNFAIR_LOCKS = y (unfair lock) B = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = n PARAVIRT_UNFAIR_LOCKS = n (queue spinlock without paravirt) C = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y PRAVIRT_SPINLOCK = y PARAVIRT_...

> 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 correctly that means you cannot select any more the old ticketlocks? As in, if you select CONFIG_PARAVIRT on X86 it wi...

...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.v...

> 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 correctly that means you cannot select any more the old ticketlocks? As in, if you select CONFIG_PARAVIRT on X86 it wi...

...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.v...

...ions(+), 13 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -692,7 +692,7 @@ config PARAVIRT_DEBUG config PARAVIRT_SPINLOCKS bool "Paravirtualization layer for spinlocks" depends on PARAVIRT && SMP - select UNINLINE_SPIN_UNLOCK + select UNINLINE_SPIN_UNLOCK if !QUEUE_SPINLOCK ---help--- Paravirtualized spinlocks allow a pvops backend to replace the spinlock implementation with something virtualization-friendly --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -712,6 +712,30 @@ static inline void __set_fixmap(unsigned #if defined...

...ions(+), 13 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -692,7 +692,7 @@ config PARAVIRT_DEBUG config PARAVIRT_SPINLOCKS bool "Paravirtualization layer for spinlocks" depends on PARAVIRT && SMP - select UNINLINE_SPIN_UNLOCK + select UNINLINE_SPIN_UNLOCK if !QUEUE_SPINLOCK ---help--- Paravirtualized spinlocks allow a pvops backend to replace the spinlock implementation with something virtualization-friendly --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -712,6 +712,30 @@ static inline void __set_fixmap(unsigned #if defined...

...nsertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index f318e78..3ddc436 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) } } } +#else /* !CONFIG_QUEUE_SPINLOCK */ + +#ifdef CONFIG_KVM_DEBUG_FS +static struct dentry *d_spin_debug; +static struct dentry *d_...

...8b45b 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -17,6 +17,55 @@ #include "xen-ops.h" #include "debugfs.h" +static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifdef CONFIG_QUEUE_SPINLOCK + +#include <asm/qspinlock.h> + +static void xen_qlock_kick(int cpu) +{ + xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); +} + +/* + * Halt the current CPU & release it back to the host + */ +static void xen_qlock_wait(u8 *byte, u8 val) +{ + int irq = __this_cpu_read(lock_kicker_irq); + +...

...avoid hang when lock info is overwritten > + * in irq spinlock slowpath and no spurious interrupt occur to save us. > + */ > + if (arch_irqs_disabled_flags(flags)) > + halt(); > + else > + safe_halt(); > + > +out: > + local_irq_restore(flags); > +} > +#endif /* QUEUE_SPINLOCK */

...avoid hang when lock info is overwritten > + * in irq spinlock slowpath and no spurious interrupt occur to save us. > + */ > + if (arch_irqs_disabled_flags(flags)) > + halt(); > + else > + safe_halt(); > + > +out: > + local_irq_restore(flags); > +} > +#endif /* QUEUE_SPINLOCK */

...nsertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index f318e78..aaf704e 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -795,6 +796,87 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) } } } +#else /* !CONFIG_QUEUE_SPINLOCK */ + +#ifdef CONFIG_KVM_DEBUG_FS +static struct dentry *d_spin_debug; +static struct dentry *d_...

...e798 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -17,6 +17,12 @@ #include "xen-ops.h" #include "debugfs.h" +static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifndef CONFIG_QUEUE_SPINLOCK + enum xen_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -100,12 +106,9 @@ struct xen_lock_waiting { __ticket_t want; }; -static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; -static DEFINE_PER_CPU(char *, irq_name); static DEFINE_PER_CPU(struct xen_lock_waiting, lock_waiting); stati...

...444c 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -17,6 +17,12 @@ #include "xen-ops.h" #include "debugfs.h" +static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifndef CONFIG_QUEUE_SPINLOCK + enum xen_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -100,12 +106,9 @@ struct xen_lock_waiting { __ticket_t want; }; -static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; -static DEFINE_PER_CPU(char *, irq_name); static DEFINE_PER_CPU(struct xen_lock_waiting, lock_waiting); stati...