This is a note to let you know that I've just added the patch titled
intel-iommu: Speed up processing of the identity_mapping
to the 2.6.39-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
intel-iommu-speed-up-processing-of-the-identity_mapping.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From cb452a4040bb051d92e85d6e7eb60c11734c1781 Mon Sep 17 00:00:00 2001
From: Mike Travis <[email protected]>
Date: Sat, 28 May 2011 13:15:03 -0500
Subject: intel-iommu: Speed up processing of the identity_mapping
function
From: Mike Travis <[email protected]>
commit cb452a4040bb051d92e85d6e7eb60c11734c1781 upstream.
When there are a large count of PCI devices, and the pass through
option for iommu is set, much time is spent in the identity_mapping
function hunting though the iommu domains to check if a specific
device is "identity mapped".
Speed up the function by checking the cached info to see if
it's mapped to the static identity domain.
Signed-off-by: Mike Travis <[email protected]>
Reviewed-by: Mike Habeck <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/pci/intel-iommu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2109,10 +2109,10 @@ static int identity_mapping(struct pci_d
if (likely(!iommu_identity_mapping))
return 0;
+ info = pdev->dev.archdata.iommu;
+ if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
+ return (info->domain == si_domain);
- list_for_each_entry(info, &si_domain->devices, link)
- if (info->dev == pdev)
- return 1;
return 0;
}
Patches currently in stable-queue which might be from [email protected] are
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