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From: "Xie, Huawei" <huawei.xie@intel.com>
To: Shivapriya Hiremath <shivpri.b@gmail.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] Why do we need iommu=pt?
Date: Mon, 20 Oct 2014 22:39:46 +0000
Message-ID: <C37D651A908B024F974696C65296B57B0F2CD832@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <CAKU5Fo_7fQHcYa-1ZBX8=D0SCkxZL8VLEpWYtJ6rG4DpV=g3gw@mail.gmail.com>



> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Shivapriya Hiremath
> Sent: Monday, October 20, 2014 2:59 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] Why do we need iommu=pt?
> 
> Hi,
> 
> My question is that if the Poll mode  driver used the DMA kernel interface
> to set up its mappings appropriately, would it still require that iommu=pt
> be set?
> What is the purpose of setting iommu=pt ?
PMD allocates memory though hugetlb file system, and fills the physical address
into the descriptor.
pt is used to pass through iotlb translation. Refer to the below link.
http://lkml.iu.edu/hypermail/linux/kernel/0906.2/02129.html
> 
> Thank you.

  reply	other threads:[~2014-10-20 22:36 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-20 21:58 Shivapriya Hiremath
2014-10-20 22:39 ` Xie, Huawei [this message]
2014-10-21  7:32   ` Alex Markuze
2014-10-21 16:53     ` Shivapriya Hiremath
2014-10-21 19:10       ` Zhou, Danny
2014-10-22  7:35         ` alex
2014-10-22  8:53           ` Liang, Cunming
2014-10-22 15:21             ` Zhou, Danny
2014-10-23  7:49               ` Alex Markuze
2014-10-27 17:27               ` Shivapriya Hiremath
2014-10-27 17:32                 ` Zhou, Danny
2014-10-30 23:22                 ` Zhou, Danny
2014-10-31  0:05                   ` Shivapriya Hiremath

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