search for: lock_spinn

...as guests. The pv spinlock assumption I will try to get re-verified by asking to reproduce under a real load with a kernel that just disables that. However, the dumps I am looking at really do look odd there. The first dump I looked at had the spinlock of runqueue[0] being placed into the per-cpu lock_spinners variable for cpu#0 and cpu#7 (doing my tests with 8 VCPUs). So apparently both cpus were waiting on the slow path for it to become free. Though actually it was free! Now, here is one issue I have in understanding the dump: the back traces produced in crash are in the normal form not showing any...

...ticketlock: make __ticket_spin_lock common x86/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: use callee-save for lock_spinning x86/ticketlock: don't inline _spin_unlock when using paravirt spinlocks x86/ticketlocks: when paravirtualizing ticket locks, increment by 2 x86/ticketlock: add slowpath logic x86/ticketlocks: tidy up __ticket_unlock_kick() arch/x86/Kconfig | 3 + arch/x8...

...ticketlock: make __ticket_spin_lock common x86/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: use callee-save for lock_spinning x86/ticketlock: don't inline _spin_unlock when using paravirt spinlocks x86/ticketlocks: when paravirtualizing ticket locks, increment by 2 x86/ticketlock: add slowpath logic x86/ticketlocks: tidy up __ticket_unlock_kick() arch/x86/Kconfig | 3 + arch/x8...

...ticketlock: make __ticket_spin_lock common x86/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: use callee-save for lock_spinning x86/ticketlock: don't inline _spin_unlock when using paravirt spinlocks x86/ticketlocks: when paravirtualizing ticket locks, increment by 2 x86/ticketlock: add slowpath logic x86/ticketlocks: tidy up __ticket_unlock_kick() arch/x86/Kconfig | 3 + arch/x8...

...6/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: keep count of blocked cpus x86/pvticketlock: use callee-save for lock_spinning x86/pvticketlock: use callee-save for unlock_kick as well x86/pvticketlock: make sure unlock is seen by everyone before checking waiters x86/ticketlock: loosen ordering restraints on unlock x86/ticketlock: prevent compiler reordering into locked region x86/ticketlock: don't inl...

...6/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: keep count of blocked cpus x86/pvticketlock: use callee-save for lock_spinning x86/pvticketlock: use callee-save for unlock_kick as well x86/pvticketlock: make sure unlock is seen by everyone before checking waiters x86/ticketlock: loosen ordering restraints on unlock x86/ticketlock: prevent compiler reordering into locked region x86/ticketlock: don't inl...

...6/ticketlock: make __ticket_spin_trylock common x86/spinlocks: replace pv spinlocks with pv ticketlocks x86/ticketlock: collapse a layer of functions xen/pvticketlock: Xen implementation for PV ticket locks x86/pvticketlock: keep count of blocked cpus x86/pvticketlock: use callee-save for lock_spinning x86/pvticketlock: use callee-save for unlock_kick as well x86/pvticketlock: make sure unlock is seen by everyone before checking waiters x86/ticketlock: loosen ordering restraints on unlock x86/ticketlock: prevent compiler reordering into locked region x86/ticketlock: don't inl...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...needs to revert below two patches to enable xen on hvm 70dd4998, f10cd522c Changes in V12 - spiltted uapi header patch. - dropped patch 18. - bailout of lock spinning in case of NMI (Gleb) - drop out patch 18 whose benefits are inconclusive (Gleb, Ingo) Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...

...needs to revert below two patches to enable xen on hvm 70dd4998, f10cd522c Changes in V12 - spiltted uapi header patch. - dropped patch 18. - bailout of lock spinning in case of NMI (Gleb) - drop out patch 18 whose benefits are inconclusive (Gleb, Ingo) Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...

...needs to revert below two patches to enable xen on hvm 70dd4998, f10cd522c Changes in V12 - spiltted uapi header patch. - dropped patch 18. - bailout of lock spinning in case of NMI (Gleb) - drop out patch 18 whose benefits are inconclusive (Gleb, Ingo) Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

...Xen (and for other pvops users, but there are none at present). PV ticketlocks keeps the existing ticketlock implemenentation (fastpath) as-is, but adds a couple of pvops for the slow paths: - If a CPU has been waiting for a spinlock for SPIN_THRESHOLD iterations, then call out to the __ticket_lock_spinning() pvop, which allows a backend to block the vCPU rather than spinning. This pvop can set the lock into "slowpath state". - When releasing a lock, if it is in "slowpath state", the call __ticket_unlock_kick() to kick the next vCPU in line awake. If the lock is no lo...

This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. The series provides implementation for both Xen and KVM. Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...

This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. The series provides implementation for both Xen and KVM. Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...

This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. The series provides implementation for both Xen and KVM. Changes in V11: - use safe_halt in lock_spinning path to avoid potential problem in case of irq_handlers taking lock in slowpath (Gleb) - add a0 flag for the kick hypercall for future extension (Gleb) - add stubs for missing architecture for kvm_vcpu_schedule() (Gleb) - Change hypercall documentation. - Rebased to 3.11-rc1 Changes in...