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From: Alex Williamson <alex.williamson@redhat.com>
To: Yunhong Jiang <yunhong.jiang@linux.intel.com>
Cc: pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/5] Threaded MSI interrupt for VFIO PCI device
Date: Thu, 03 Dec 2015 11:55:53 -0700	[thread overview]
Message-ID: <1449168953.15753.216.camel@redhat.com> (raw)
In-Reply-To: <1449166972-8894-1-git-send-email-yunhong.jiang@linux.intel.com>

On Thu, 2015-12-03 at 10:22 -0800, Yunhong Jiang wrote:
> When assigning a VFIO device to a KVM guest with low latency requirement, it  
> is better to handle the interrupt in the hard interrupt context, to reduce 
> the context switch to/from the IRQ thread.
> 
> Based on discussion on https://lkml.org/lkml/2015/10/26/764, the VFIO msi 
> interrupt is changed to use request_threaded_irq(). The primary interrupt 
> handler tries to set the guest interrupt atomically. If it fails to achieve 
> it, a threaded interrupt handler will be invoked.
> 
> The irq_bypass manager is extended for this purpose. The KVM eventfd will 
> provide a irqbypass consumer to handle the interrupt at hard interrupt 
> context. The producer will invoke the consumer's handler then.

Do you have any performance data?  Thanks,

Alex


  parent reply	other threads:[~2015-12-03 18:55 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-03 18:22 [PATCH 0/5] Threaded MSI interrupt for VFIO PCI device Yunhong Jiang
2015-12-03 18:22 ` [PATCH 1/5] KVM: Extract the irqfd_wakeup_pollin/irqfd_wakeup_pollup Yunhong Jiang
2015-12-03 18:22 ` [PATCH 2/5] VIRT: Support runtime irq_bypass consumer Yunhong Jiang
2015-12-16 19:48   ` Alex Williamson
2015-12-03 18:22 ` [PATCH 3/5] VFIO: Support threaded interrupt handling on VFIO Yunhong Jiang
2015-12-16 19:49   ` Alex Williamson
2015-12-03 18:22 ` [PATCH 4/5] KVM: Add the irq handling consumer Yunhong Jiang
2015-12-04  0:33   ` kbuild test robot
2015-12-03 18:22 ` [PATCH 5/5] KVM: Expose x86 kvm_arch_set_irq_inatomic() Yunhong Jiang
2015-12-03 18:55 ` Alex Williamson [this message]
2015-12-03 22:31   ` [PATCH 0/5] Threaded MSI interrupt for VFIO PCI device Yunhong Jiang
2015-12-16 17:56 ` Paolo Bonzini
2015-12-16 19:15   ` Alex Williamson
2015-12-16 21:55     ` Paolo Bonzini
2016-01-06  7:42       ` Yunhong Jiang
2016-01-06  7:40     ` Yunhong Jiang

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