search for: slowpaths

* Greg KH <gregkh at linuxfoundation.org> wrote: > On Tue, Feb 24, 2015 at 02:54:59PM +0530, Raghavendra K T wrote: > > Paravirt spinlock clears slowpath flag after doing unlock. > > As explained by Linus currently it does: > > prev = *lock; > > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > > >

* Greg KH <gregkh at linuxfoundation.org> wrote: > On Tue, Feb 24, 2015 at 02:54:59PM +0530, Raghavendra K T wrote: > > Paravirt spinlock clears slowpath flag after doing unlock. > > As explained by Linus currently it does: > > prev = *lock; > > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > > >

On Tue, Jun 17, 2014 at 04:51:57PM -0400, Waiman Long wrote: > On 06/17/2014 04:36 PM, Konrad Rzeszutek Wilk wrote: > >On Sun, Jun 15, 2014 at 02:47:00PM +0200, Peter Zijlstra wrote: > >>Because the qspinlock needs to touch a second cacheline; add a pending > >>bit and allow a single in-word spinner before we punt to the second > >>cacheline. > >Could you

On Tue, Jun 17, 2014 at 04:51:57PM -0400, Waiman Long wrote: > On 06/17/2014 04:36 PM, Konrad Rzeszutek Wilk wrote: > >On Sun, Jun 15, 2014 at 02:47:00PM +0200, Peter Zijlstra wrote: > >>Because the qspinlock needs to touch a second cacheline; add a pending > >>bit and allow a single in-word spinner before we punt to the second > >>cacheline. > >Could you

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which is

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which is

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which is

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which is

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which

The decision whether the slowpath flag is to be cleared for paravirtualized spinlocks is located in __ticket_check_and_clear_slowpath() today. Move that decision into arch_spin_lock() and add an unlikely attribute to it to avoid calling a function in case the compiler chooses not to inline __ticket_check_and_clear_slowpath() and the slowpath flag isn't set. Signed-off-by: Juergen Gross

On Jun 17, 2014 6:25 PM, Waiman Long <waiman.long at hp.com> wrote: > > On 06/17/2014 05:10 PM, Konrad Rzeszutek Wilk wrote: > > On Tue, Jun 17, 2014 at 05:07:29PM -0400, Konrad Rzeszutek Wilk wrote: > >> On Tue, Jun 17, 2014 at 04:51:57PM -0400, Waiman Long wrote: > >>> On 06/17/2014 04:36 PM, Konrad Rzeszutek Wilk wrote: > >>>> On Sun,

On Jun 17, 2014 6:25 PM, Waiman Long <waiman.long at hp.com> wrote: > > On 06/17/2014 05:10 PM, Konrad Rzeszutek Wilk wrote: > > On Tue, Jun 17, 2014 at 05:07:29PM -0400, Konrad Rzeszutek Wilk wrote: > >> On Tue, Jun 17, 2014 at 04:51:57PM -0400, Waiman Long wrote: > >>> On 06/17/2014 04:36 PM, Konrad Rzeszutek Wilk wrote: > >>>> On Sun,

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which

Paravirt spinlock clears slowpath flag after doing unlock. As explained by Linus currently it does: prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); which

On 02/15/2015 11:25 AM, Raghavendra K T wrote: > Paravirt spinlock clears slowpath flag after doing unlock. > As explained by Linus currently it does: > prev = *lock; > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > /* add_smp() is a full mb() */ > > if (unlikely(lock->tickets.tail &

On 02/15/2015 11:25 AM, Raghavendra K T wrote: > Paravirt spinlock clears slowpath flag after doing unlock. > As explained by Linus currently it does: > prev = *lock; > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > /* add_smp() is a full mb() */ > > if (unlikely(lock->tickets.tail &

On Tue, Feb 24, 2015 at 02:54:59PM +0530, Raghavendra K T wrote: > Paravirt spinlock clears slowpath flag after doing unlock. > As explained by Linus currently it does: > prev = *lock; > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > /* add_smp() is a full mb() */ > > if

On Tue, Feb 24, 2015 at 02:54:59PM +0530, Raghavendra K T wrote: > Paravirt spinlock clears slowpath flag after doing unlock. > As explained by Linus currently it does: > prev = *lock; > add_smp(&lock->tickets.head, TICKET_LOCK_INC); > > /* add_smp() is a full mb() */ > > if

From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> This series replaces the existing paravirtualized spinlock mechanism with a paravirtualized ticketlock mechanism. The series provides implementation for both Xen and KVM. The current set of patches are for Xen/x86 spinlock/KVM guest side, to be included against -tip. A separate patchset for KVM host based on kvm tree is already