From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
To: Avi Kivity <avi@redhat.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
Greg Kroah-Hartman <gregkh@suse.de>,
"H. Peter Anvin" <hpa@zytor.com>, Gleb Natapov <gleb@redhat.com>,
Virtualization <virtualization@lists.linux-foundation.org>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
x86@kernel.org, KVM <kvm@vger.kernel.org>,
Dave Jiang <dave.jiang@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Xen <xen-devel@lists.xensource.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Yinghai Lu <yinghai@kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Rik van Riel <riel@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
LKML <linux-kernel@vger.kernel.org>,
Suzuki Poulose <suzuki@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH RFC V2 3/5] kvm hypervisor : Add two hypercalls to support pv-ticketlock
Date: Mon, 24 Oct 2011 17:57:34 +0530 [thread overview]
Message-ID: <20111024122734.GA10634@linux.vnet.ibm.com> (raw)
In-Reply-To: <4EA53A7D.300@redhat.com>
* Avi Kivity <avi@redhat.com> [2011-10-24 12:14:21]:
> > +/*
> > + * kvm_pv_wait_for_kick_op : Block until kicked by either a KVM_HC_KICK_CPU
> > + * hypercall or a event like interrupt.
> > + *
> > + * @vcpu : vcpu which is blocking.
> > + */
> > +static void kvm_pv_wait_for_kick_op(struct kvm_vcpu *vcpu)
> > +{
[snip]
> > +}
>
> This hypercall can be replaced by a HLT instruction, no?
Good point. Assuming yield_on_hlt=1, that would allow the vcpu to be put
to sleep and let other vcpus make progress.
I guess with that change, we can also dropthe need for other hypercall
introduced in this patch (kvm_pv_kick_cpu_op()). Essentially a vcpu sleeping
because of HLT instruction can be woken up by a IPI issued by vcpu releasing a
lock.
- vatsa
next prev parent reply other threads:[~2011-10-24 12:27 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-23 19:03 [PATCH RFC V2 0/5] kvm : Paravirt-spinlock support for KVM guests Raghavendra K T
2011-10-23 19:03 ` Raghavendra K T
2011-10-23 19:04 ` [PATCH RFC V2 1/5] debugfs: Add support to print u32 array in debugfs Raghavendra K T
2011-10-23 19:04 ` Raghavendra K T
2011-10-23 22:20 ` Greg KH
2011-10-24 9:30 ` Raghavendra K T
2011-10-23 19:04 ` Raghavendra K T
2011-10-23 19:04 ` [PATCH RFC V2 2/5] debugfs: Renaming of xen functions and change unsigned to u32 Raghavendra K T
2011-10-23 19:04 ` Raghavendra K T
2011-10-23 19:04 ` Raghavendra K T
2011-10-23 22:19 ` Greg KH
2011-10-24 9:28 ` Raghavendra K T
2011-10-24 9:38 ` Greg KH
2011-10-23 19:05 ` [PATCH RFC V2 3/5] kvm hypervisor : Add two hypercalls to support pv-ticketlock Raghavendra K T
2011-10-23 19:05 ` Raghavendra K T
2011-10-23 19:05 ` Raghavendra K T
2011-10-24 10:01 ` Sasha Levin
2011-10-24 10:01 ` Sasha Levin
2011-10-24 11:00 ` Raghavendra K T
2011-10-24 11:00 ` Raghavendra K T
2011-10-24 11:00 ` Raghavendra K T
2011-10-24 10:14 ` Avi Kivity
2011-10-24 11:20 ` Raghavendra K T
2011-10-24 12:27 ` Srivatsa Vaddagiri [this message]
2011-10-24 13:09 ` Avi Kivity
2011-10-24 13:50 ` Srivatsa Vaddagiri
2011-10-25 18:24 ` Raghavendra K T
2011-10-26 10:34 ` Avi Kivity
2011-10-26 19:08 ` Raghavendra K T
2011-10-26 19:08 ` Raghavendra K T
2011-10-26 19:08 ` Raghavendra K T
2011-10-27 10:17 ` Avi Kivity
2011-10-27 10:17 ` Avi Kivity
2011-10-26 20:09 ` Jeremy Fitzhardinge
2011-10-26 20:09 ` Jeremy Fitzhardinge
2011-10-26 20:09 ` Jeremy Fitzhardinge
2011-10-23 19:07 ` [PATCH RFC V2 4/5] kvm guest : Added configuration support to enable debug information for KVM Guests Raghavendra K T
2011-10-23 19:07 ` Raghavendra K T
2011-10-23 19:07 ` Raghavendra K T
2011-10-24 10:01 ` Sasha Levin
2011-10-24 10:01 ` Sasha Levin
2011-10-24 18:45 ` Raghavendra K T
2011-10-24 18:45 ` Raghavendra K T
2011-10-24 18:45 ` Raghavendra K T
2011-10-24 10:15 ` Avi Kivity
2011-10-25 18:11 ` Raghavendra K T
2011-10-25 18:30 ` Jeremy Fitzhardinge
2011-10-23 19:07 ` [PATCH RFC V2 5/5] kvm guest : pv-ticketlocks support for linux guests running on KVM hypervisor Raghavendra K T
2011-10-24 10:01 ` Sasha Levin
2011-10-24 9:33 ` Raghavendra K T
2011-10-24 9:33 ` Raghavendra K T
2011-10-24 9:33 ` Raghavendra K T
2011-10-25 18:34 ` Jeremy Fitzhardinge
2011-10-26 19:23 ` Raghavendra K T
2011-10-26 19:46 ` Jeremy Fitzhardinge
2011-10-26 19:55 ` Raghavendra K T
2011-10-25 18:35 ` Jeremy Fitzhardinge
2011-10-26 19:25 ` Raghavendra K T
2011-10-23 19:07 ` Raghavendra K T
2011-10-23 19:07 ` Raghavendra K T
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