Bug 518103
Summary: | VTD IOMMU 1:1 mapping performance and bug fixes | ||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | Don Dutile (Red Hat) <ddutile> |
Component: | kernel | Assignee: | Don Dutile (Red Hat) <ddutile> |
Status: | CLOSED ERRATA | QA Contact: | Red Hat Kernel QE team <kernel-qe> |
Severity: | medium | Docs Contact: | |
Priority: | low | ||
Version: | 5.5 | CC: | chrisw, emcnabb, jtluka, rlerch |
Target Milestone: | rc | ||
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: |
Cause: INTEL IOMMUs with hardware-assisted, host IOMMU pass-through support had unnecessary performance degradation.
Consequence: If IOMMU enabled, and only using host devices, high rate of small DMA packets could cause performance degradation.
Fix: Enable use of new hardware-assisted IOMMU pass-through, which minimizes hardware overhead of DMA address -> to -> system address translation.
Result: Improved IO performance on newer INTEL machines with IOMMU support
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Story Points: | --- |
Clone Of: | Environment: | ||
Last Closed: | 2010-03-30 07:41:14 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: | |||
Bug Depends On: | |||
Bug Blocks: | 526946, 533192, 541103 |
Description
Don Dutile (Red Hat)
2009-08-18 21:32:03 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. Posted 9 patch change set to rkml. Essentially backported intel-iommu changes from 2.6.32 along with 5 extras in iommu-2.6.32.git that are staged for 2.6.32-stable (and in F13/rawhide). in kernel-2.6.18-180.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Please update the appropriate value in the Verified field (cf_verified) to indicate this fix has been successfully verified. Include a comment with verification details. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2010-0178.html filled in doc fields |