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From: Peter Zijlstra <peterz@infradead.org>
To: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	virtualization@lists.linux-foundation.org,
	linux-s390@vger.kernel.org, mingo@redhat.com, mpe@ellerman.id.au,
	paulus@samba.org, benh@kernel.crashing.org,
	paulmck@linux.vnet.ibm.com, waiman.long@hpe.com,
	will.deacon@arm.com, boqun.feng@gmail.com, dave@stgolabs.net,
	schwidefsky@de.ibm.com, pbonzini@redhat.com
Subject: Re: [PATCH v2 0/4] implement vcpu preempted check
Date: Wed, 6 Jul 2016 08:52:55 +0200	[thread overview]
Message-ID: <20160706065255.GH30909@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1467124991-13164-1-git-send-email-xinhui.pan@linux.vnet.ibm.com>

On Tue, Jun 28, 2016 at 10:43:07AM -0400, Pan Xinhui wrote:
> change fomr v1:
> 	a simplier definition of default vcpu_is_preempted
> 	skip mahcine type check on ppc, and add config. remove dedicated macro.
> 	add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. 
> 	add more comments
> 	thanks boqun and Peter's suggestion.
> 
> This patch set aims to fix lock holder preemption issues.
> 
> test-case:
> perf record -a perf bench sched messaging -g 400 -p && perf report
> 
> 18.09%  sched-messaging  [kernel.vmlinux]  [k] osq_lock
> 12.28%  sched-messaging  [kernel.vmlinux]  [k] rwsem_spin_on_owner
>  5.27%  sched-messaging  [kernel.vmlinux]  [k] mutex_unlock
>  3.89%  sched-messaging  [kernel.vmlinux]  [k] wait_consider_task
>  3.64%  sched-messaging  [kernel.vmlinux]  [k] _raw_write_lock_irq
>  3.41%  sched-messaging  [kernel.vmlinux]  [k] mutex_spin_on_owner.is
>  2.49%  sched-messaging  [kernel.vmlinux]  [k] system_call
> 
> We introduce interface bool vcpu_is_preempted(int cpu) and use it in some spin
> loops of osq_lock, rwsem_spin_on_owner and mutex_spin_on_owner.
> These spin_on_onwer variant also cause rcu stall before we apply this patch set
> 

Paolo, could you help out with an (x86) KVM interface for this?

Waiman, could you see if you can utilize this to get rid of the
SPIN_THRESHOLD in qspinlock_paravirt?

  parent reply	other threads:[~2016-07-06  6:53 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-28 14:43 [PATCH v2 0/4] implement vcpu preempted check Pan Xinhui
2016-06-28 14:43 ` [PATCH v2 1/4] kernel/sched: introduce vcpu preempted check interface Pan Xinhui
2016-06-28 14:43 ` [PATCH v2 2/4] powerpc/spinlock: support vcpu preempted check Pan Xinhui
2016-07-05  9:57   ` Wanpeng Li
2016-07-06  4:58     ` xinhui
2016-07-06  6:46       ` Wanpeng Li
2016-07-06  7:58         ` Peter Zijlstra
2016-07-06  8:32           ` Wanpeng Li
2016-07-06 10:18             ` xinhui
2016-07-06 10:54   ` Balbir Singh
2016-07-15 15:35     ` Pan Xinhui
2016-06-28 14:43 ` [PATCH v2 3/4] locking/osq: Drop the overload of osq_lock() Pan Xinhui
2016-06-28 14:43 ` [PATCH v2 4/4] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner Pan Xinhui
2016-07-06  6:52 ` Peter Zijlstra [this message]
2016-07-06  7:47   ` [PATCH v2 0/4] implement vcpu preempted check Juergen Gross
2016-07-06  8:19     ` Peter Zijlstra
2016-07-06  8:38       ` Juergen Gross
2016-07-06 12:44       ` Paolo Bonzini
2016-07-06 16:56       ` Christian Borntraeger
2016-07-06 10:05   ` xinhui
2016-07-06 10:44   ` Paolo Bonzini
2016-07-06 11:59     ` Peter Zijlstra
2016-07-06 12:08     ` Wanpeng Li
2016-07-06 12:28       ` Paolo Bonzini
2016-07-06 13:03         ` Wanpeng Li
2016-07-07  8:48         ` Wanpeng Li
2016-07-07  9:42           ` Peter Zijlstra
2016-07-07 10:12             ` Wanpeng Li
2016-07-07 10:27               ` Wanpeng Li
2016-07-07 11:15                 ` Peter Zijlstra
2016-07-07 11:08               ` Peter Zijlstra
2016-07-07 11:09             ` Peter Zijlstra
2016-07-07 11:21             ` Peter Zijlstra
2016-07-11 15:10   ` Waiman Long
2016-07-12  4:16     ` Juergen Gross
2016-07-12 18:16       ` Waiman Long

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