From: Matthew Wilcox <matthew@wil.cx>
To: Yu Zhao <yu.zhao@intel.com>
Cc: jbarnes@virtuousgeek.org, dwmw2@infradead.org,
linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 0/6] ATS capability support for Intel IOMMU
Date: Thu, 12 Feb 2009 20:44:57 -0700 [thread overview]
Message-ID: <20090213034457.GM3624@parisc-linux.org> (raw)
In-Reply-To: <1234443038-15437-1-git-send-email-yu.zhao@intel.com>
On Thu, Feb 12, 2009 at 08:50:32PM +0800, Yu Zhao wrote:
> 2, avoid using pci_find_ext_capability every time when reading ATS
> Invalidate Queue Depth (Matthew Wilcox)
er ... I didn't say it was a problem. I said I couldn't tell if it was a
problem. There's no point in taking up an extra 4 bytes per pci_dev if
it's not a performance problem. How often do we query the queue depth?
Is this something a device driver will call once per device and then
remember for itself, or only use at setup? Or is it something we call
every millisecond?
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next prev parent reply other threads:[~2009-02-13 3:45 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-12 12:50 [PATCH v3 0/6] ATS capability support for Intel IOMMU Yu Zhao
2009-02-12 12:50 ` [PATCH v3 1/6] PCI: support the ATS capability Yu Zhao
2009-02-12 12:50 ` [PATCH v3 2/6] VT-d: parse ATSR in DMA Remapping Reporting Structure Yu Zhao
2009-02-12 12:50 ` [PATCH v3 3/6] VT-d: add queue invalidation fault status support Yu Zhao
2009-02-12 12:50 ` [PATCH v3 4/6] VT-d: add device IOTLB invalidation support Yu Zhao
2009-02-12 12:50 ` [PATCH v3 5/6] VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps Yu Zhao
2009-02-12 12:50 ` [PATCH v3 6/6] VT-d: support the device IOTLB Yu Zhao
2009-02-14 23:20 ` Grant Grundler
2009-02-26 3:21 ` Yu Zhao
2009-02-13 3:44 ` Matthew Wilcox [this message]
2009-02-13 5:27 ` [PATCH v3 0/6] ATS capability support for Intel IOMMU Zhao, Yu
2009-02-14 22:59 ` Grant Grundler
2009-02-26 2:50 ` Yu Zhao
2009-02-26 3:46 ` Greg KH
2009-02-27 7:19 ` Grant Grundler
2009-03-20 2:30 ` Jesse Barnes
2009-03-20 2:30 ` Jesse Barnes
2009-03-20 2:47 ` Zhao, Yu
2009-03-20 11:15 ` David Woodhouse
2009-03-23 5:22 ` Yu Zhao
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