Subject: Intel iommu: Speed up processing of the identity_mapping function 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 <travis@xxxxxxx> --- drivers/pci/intel-iommu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- linux-2.6.32.orig/drivers/pci/intel-iommu.c +++ linux-2.6.32/drivers/pci/intel-iommu.c @@ -2124,10 +2124,10 @@ 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
