similar to: [PATCH-tip v2 0/2] x86/paravirt: Enable users to choose PV lock type

On 11/01/2017 04:58 PM, Waiman Long wrote: > +/* TODO: To be removed in a future kernel version */ > static __init int xen_parse_nopvspin(char *arg) > { > - xen_pvspin = false; > + pr_warn("xen_nopvspin is deprecated, replace it with \"pvlock_type=queued\"!\n"); > + if (!pv_spinlock_type) > + pv_spinlock_type = locktype_queued; Since we currently end up

On 11/01/2017 04:58 PM, Waiman Long wrote: > +/* TODO: To be removed in a future kernel version */ > static __init int xen_parse_nopvspin(char *arg) > { > - xen_pvspin = false; > + pr_warn("xen_nopvspin is deprecated, replace it with \"pvlock_type=queued\"!\n"); > + if (!pv_spinlock_type) > + pv_spinlock_type = locktype_queued; Since we currently end up

Currently, there are 3 different lock types that can be chosen for the x86 architecture: - qspinlock - pvqspinlock - unfair lock One of the above lock types will be chosen at boot time depending on a number of different factors. Ideally, the hypervisors should be able to pick the best performing lock type for the current VM configuration. That is not currently the case as the performance of

Currently, there are 3 different lock types that can be chosen for the x86 architecture: - qspinlock - pvqspinlock - unfair lock One of the above lock types will be chosen at boot time depending on a number of different factors. Ideally, the hypervisors should be able to pick the best performing lock type for the current VM configuration. That is not currently the case as the performance of

With the new pvlock_type kernel parameter, xen_nopvspin is no longer needed. This patch deprecates the xen_nopvspin parameter by removing its documentation and treating it as an alias of "pvlock_type=queued". Signed-off-by: Waiman Long <longman at redhat.com> --- Documentation/admin-guide/kernel-parameters.txt | 4 ---- arch/x86/xen/spinlock.c | 19

On 11/01/2017 11:51 AM, Juergen Gross wrote: > On 01/11/17 16:32, Waiman Long wrote: >> Currently, there are 3 different lock types that can be chosen for >> the x86 architecture: >> >> - qspinlock >> - pvqspinlock >> - unfair lock >> >> One of the above lock types will be chosen at boot time depending on >> a number of different factors.

On 11/01/2017 11:51 AM, Juergen Gross wrote: > On 01/11/17 16:32, Waiman Long wrote: >> Currently, there are 3 different lock types that can be chosen for >> the x86 architecture: >> >> - qspinlock >> - pvqspinlock >> - unfair lock >> >> One of the above lock types will be chosen at boot time depending on >> a number of different factors.

On 01/11/17 16:32, Waiman Long wrote: > Currently, there are 3 different lock types that can be chosen for > the x86 architecture: > > - qspinlock > - pvqspinlock > - unfair lock > > One of the above lock types will be chosen at boot time depending on > a number of different factors. > > Ideally, the hypervisors should be able to pick the best performing >

On 11/01/2017 06:01 PM, Boris Ostrovsky wrote: > On 11/01/2017 04:58 PM, Waiman Long wrote: >> +/* TODO: To be removed in a future kernel version */ >> static __init int xen_parse_nopvspin(char *arg) >> { >> - xen_pvspin = false; >> + pr_warn("xen_nopvspin is deprecated, replace it with \"pvlock_type=queued\"!\n"); >> + if

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V2: - use static key instead of making virt_spin_lock() a pvops function Juergen Gross

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V2: - use static key instead of making virt_spin_lock() a pvops function Juergen Gross

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V3: - remove test for hypervisor environment from virt_spin_lock(9 as suggested by

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V3: - remove test for hypervisor environment from virt_spin_lock(9 as suggested by

This is a follow-up of commit cfd8983f03c7b2 ("x86, locking/spinlocks: Remove ticket (spin)lock implementation"). The static_key structure paravirt_ticketlocks_enabled is now removed as it is no longer used. As a result, the init functions kvm_spinlock_init_jump() and xen_init_spinlocks_jump() are also removed. A simple build and boot test was done to verify it. Signed-off-by: Waiman

This is a follow-up of commit cfd8983f03c7b2 ("x86, locking/spinlocks: Remove ticket (spin)lock implementation"). The static_key structure paravirt_ticketlocks_enabled is now removed as it is no longer used. As a result, the init functions kvm_spinlock_init_jump() and xen_init_spinlocks_jump() are also removed. A simple build and boot test was done to verify it. Signed-off-by: Waiman

With virt_spin_lock() being a pvops function the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. Juergen Gross (4): paravirt: add generic _paravirt_false() function paravirt: switch

With virt_spin_lock() being a pvops function the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. Juergen Gross (4): paravirt: add generic _paravirt_false() function paravirt: switch

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. (targeted for 3.5 window) Changes in V7: - Reabsed patches to 3.4-rc3 - Added jumplabel split patch (originally from Andrew Jones rebased to 3.4-rc3 - jumplabel changes from Ingo and Jason taken and now using

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. (targeted for 3.5 window) Changes in V7: - Reabsed patches to 3.4-rc3 - Added jumplabel split patch (originally from Andrew Jones rebased to 3.4-rc3 - jumplabel changes from Ingo and Jason taken and now using

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Changes since last posting: (Raghavendra K T) [ - Rebased to linux-3.3-rc6. - used function+enum in place of macro (better type checking) - use cmpxchg while resetting zero status for possible race [suggested by Dave Hansen for KVM patches ] ] This series replaces the existing paravirtualized spinlock mechanism with a