search for: static_key_slow_inc

...nabled)) { + static_key_false(&paravirt_spinlocks_enabled)) { arch_spinlock_t prev; prev = *lock; --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -819,7 +819,7 @@ static __init int kvm_spinlock_init_jump if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return 0; - static_key_slow_inc(&paravirt_ticketlocks_enabled); + static_key_slow_inc(&paravirt_spinlocks_enabled); printk(KERN_INFO "KVM setup paravirtual spinlock\n"); return 0; --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -16,5 +16,5 @@ struct pv_lock_ops pv_l...

...prev = *lock; diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 94f6434..2f1bcc9 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -834,7 +834,7 @@ static __init int kvm_spinlock_init_jump(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return 0; - static_key_slow_inc(&paravirt_ticketlocks_enabled); + static_key_slow_inc(&paravirt_spinlocks_enabled); printk(KERN_INFO "KVM setup paravirtual spinlock\n"); return 0; diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index bbb6c73..e434f24 100644 --- a/ar...

...prev = *lock; diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 94f6434..2f1bcc9 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -834,7 +834,7 @@ static __init int kvm_spinlock_init_jump(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return 0; - static_key_slow_inc(&paravirt_ticketlocks_enabled); + static_key_slow_inc(&paravirt_spinlocks_enabled); printk(KERN_INFO "KVM setup paravirtual spinlock\n"); return 0; diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index bbb6c73..e434f24 100644 --- a/ar...

From: Andrei Vagin <avagin at gmail.com> The definition of static_key_slow_inc() has cpus_read_lock in place. In the virtio_net driver, XPS queues are initialized after setting the queue:cpu affinity in virtnet_set_affinity() which is already protected within cpus_read_lock. Lockdep prints a warning when we are trying to acquire cpus_read_lock when it is already held. This p...

...inlock.h> /* diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 36bc664..6750fdc 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -627,7 +627,6 @@ static __init int kvm_spinlock_init_jump(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return 0; - static_key_slow_inc(&paravirt_ticketlocks_enabled); printk(KERN_INFO "KVM setup paravirtual spinlock\n"); return 0; diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6d4bf81..6259327 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel...

...inlock.h> /* diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 36bc664..6750fdc 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -627,7 +627,6 @@ static __init int kvm_spinlock_init_jump(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return 0; - static_key_slow_inc(&paravirt_ticketlocks_enabled); printk(KERN_INFO "KVM setup paravirtual spinlock\n"); return 0; diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6d4bf81..6259327 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel...

....099fcba 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -620,18 +620,4 @@ void __init kvm_spinlock_init(void) } } -static __init int kvm_spinlock_init_jump(void) -{ - if (!kvm_para_available()) - return 0; - if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) - return 0; - - static_key_slow_inc(&paravirt_ticketlocks_enabled); - printk(KERN_INFO "KVM setup paravirtual spinlock\n"); - - return 0; -} -early_initcall(kvm_spinlock_init_jump); - #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6d...

....099fcba 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -620,18 +620,4 @@ void __init kvm_spinlock_init(void) } } -static __init int kvm_spinlock_init_jump(void) -{ - if (!kvm_para_available()) - return 0; - if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) - return 0; - - static_key_slow_inc(&paravirt_ticketlocks_enabled); - printk(KERN_INFO "KVM setup paravirtual spinlock\n"); - - return 0; -} -early_initcall(kvm_spinlock_init_jump); - #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6d...

On Thu, Aug 02, 2018 at 02:04:12PM -0700, Nambiar, Amritha wrote: > On 8/1/2018 5:11 PM, Andrei Vagin wrote: > > On Tue, Jul 10, 2018 at 07:28:49PM -0700, Nambiar, Amritha wrote: > >> With this patch series, I introduced static_key for XPS maps > >> (xps_needed), so static_key_slow_inc() is used to switch branches. The > >> definition of static_key_slow_inc() has cpus_read_lock in place. In the > >> virtio_net driver, XPS queues are initialized after setting the > >> queue:cpu affinity in virtnet_set_affinity() which is already protected > >> w...

..._PARAVIRT_SPINLOCKS */ > + > +#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump); > +#endif > I think this should apply to all paravirt implementations, unless pv_lock_ops.kick_cpu != NULL....

..._PARAVIRT_SPINLOCKS */ > + > +#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump); > +#endif > I think this should apply to all paravirt implementations, unless pv_lock_ops.kick_cpu != NULL....

..._PARAVIRT_SPINLOCKS */ > + > +#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump); > +#endif > No! Please do what I asked you to do. You are not handling Hyper-V or VMWare. Just use X86_F...

..._PARAVIRT_SPINLOCKS */ > + > +#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump); > +#endif > No! Please do what I asked you to do. You are not handling Hyper-V or VMWare. Just use X86_F...

Hi all, this patch series introduces stolen ticks accounting for Xen on ARM. Stolen ticks are clocksource ticks that have been "stolen" from the cpu, typically because Linux is running in a virtual machine and the vcpu has been descheduled. To account for these ticks we introduce CONFIG_PARAVIRT and pv_time_ops so that we can make use of:

Hello, This patchset introduces steal time accounting support for the VMware guest. The idea and implementation of guest steal time support is similar to KVM ones and it is based on steal clock. The steal clock is a per CPU structure in a shared memory between hypervisor and guest, initialized by each CPU through hypercall. Steal clock is got updated by the hypervisor and read by the guest. The

...) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+604f8271211546f5b3c7 at syzkaller.appspotmail.com > > possible deadlock in static_key_slow_incsd 0:0:1:0: [sda] Attached SCSI disk > MACsec IEEE 802.1AE > tun: Universal TUN/TAP device driver, 1.6 > > ============================================ > WARNING: possible recursive locking detected +Tetsuo, perhaps this boot lockdep problem then disables lockdep for actual testing....

...) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+604f8271211546f5b3c7 at syzkaller.appspotmail.com > > possible deadlock in static_key_slow_incsd 0:0:1:0: [sda] Attached SCSI disk > MACsec IEEE 802.1AE > tun: Universal TUN/TAP device driver, 1.6 > > ============================================ > WARNING: possible recursive locking detected +Tetsuo, perhaps this boot lockdep problem then disables lockdep for actual testing....

...-0700, Nambiar, Amritha wrote: > > > On 8/1/2018 5:11 PM, Andrei Vagin wrote: > > > > On Tue, Jul 10, 2018 at 07:28:49PM -0700, Nambiar, Amritha wrote: > > > >> With this patch series, I introduced static_key for XPS maps > > > >> (xps_needed), so static_key_slow_inc() is used to switch branches. The > > > >> definition of static_key_slow_inc() has cpus_read_lock in place. In the > > > >> virtio_net driver, XPS queues are initialized after setting the > > > >> queue:cpu affinity in virtnet_set_affinity() which is alr...

...; > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+604f8271211546f5b3c7 at syzkaller.appspotmail.com > > > > possible deadlock in static_key_slow_incsd 0:0:1:0: [sda] Attached SCSI disk > > MACsec IEEE 802.1AE > > tun: Universal TUN/TAP device driver, 1.6 > > > > ============================================ > > WARNING: possible recursive locking detected > > +Tetsuo, perhaps this boot lockdep problem then...

...diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c > index e8a9ea7..a822606 100644 > --- a/arch/x86/xen/spinlock.c > +++ b/arch/x86/xen/spinlock.c > @@ -155,7 +155,6 @@ static __init int xen_init_spinlocks_jump(void) > if (!xen_domain()) > return 0; > > - static_key_slow_inc(&paravirt_ticketlocks_enabled); > return 0; > } > early_initcall(xen_init_spinlocks_jump); Looks that with this change there is not much left of xen_init_spinlocks_jump() and so it can be removed. -boris