From: Peter Zijlstra <peterz@infradead.org>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: jeremy@goop.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
paul.gortmaker@windriver.com, hpa@zytor.com, ak@linux.intel.com,
gleb@redhat.com, x86@kernel.org, mingo@redhat.com,
xen-devel@lists.xenproject.org, paulmck@linux.vnet.ibm.com,
riel@redhat.com, konrad.wilk@oracle.com, oleg@redhat.com,
davej@redhat.com, tglx@linutronix.de, fernando_b1@lab.ntt.co.jp,
chegu_vinod@hp.com, waiman.long@hp.com,
linux-kernel@vger.kernel.org, pbonzini@redhat.com,
torvalds@linux-foundation.org
Subject: Re: [RFC] Implement Batched (group) ticket lock
Date: Thu, 29 May 2014 08:46:06 +0200 [thread overview]
Message-ID: <20140529064606.GH19143@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <1401279399-23854-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com>
On Wed, May 28, 2014 at 05:46:39PM +0530, Raghavendra K T wrote:
> In virtualized environment there are mainly three problems
> related to spinlocks that affect performance.
> 1. LHP (lock holder preemption)
> 2. Lock Waiter Preemption (LWP)
> 3. Starvation/fairness
>
> Though ticketlocks solve the fairness problem, it worsens LWP, LHP problems.
> pv-ticketlocks tried to address this. But we can further improve at the
> cost of relaxed fairness.
So I really hate the idea of having different locks for paravirt and
normal kernels.
And we're looking to move to that queued lock for normal kernels.
next prev parent reply other threads:[~2014-05-29 6:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-28 12:16 [RFC] Implement Batched (group) ticket lock Raghavendra K T
2014-05-28 21:55 ` Rik van Riel
2014-05-28 22:19 ` Linus Torvalds
2014-05-28 22:29 ` Thomas Gleixner
2014-05-29 1:18 ` Rik van Riel
2014-05-29 9:44 ` Raghavendra K T
2014-05-29 6:46 ` Peter Zijlstra [this message]
2014-05-29 9:51 ` Raghavendra K T
2014-05-29 22:45 ` Waiman Long
2014-05-30 8:53 ` Raghavendra K T
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