| From: Harsh Jain <Harsh@xxxxxxxxxxx> | Sent: Friday, September 29, 2017 1:14:45 AM | | Robin, | | I tried running patch on our test setup. | | With "intel_iommu=on" : I can see single occurrence of DMAR Write failure | on perf traffic with 10 thread. | | [ 749.616480] perf: interrupt took too long (3203 > 3202), lowering kernel.perf_event_max_sample_rate to 62000 | [ 852.500671] DMAR: DRHD: handling fault status reg 2 | [ 852.506039] DMAR: [DMA Write] Request device [02:00.4] fault addr ef919000 [fault reason 05] PTE Write access is not set | [root@heptagon linux_t4_build]# cat /proc/cmdline | BOOT_IMAGE=/vmlinuz-4.9.51+ root=UUID=ccbb7f18-b3f0-43df-89de-07521e9c02fe ro intel_iommu=on crashkernel=auto rhgb quiet rhgb quiet console=ttyS0,115200, console=tty0 LANG=en_US.UTF-8 Harsh. Can you provide the debugging information for that one DMA FAILURE trace? It May be yet another corner case in __domain_mapping() or a different path. | With intel_iommu=sp_off : It works fine for more than 30 minutes without | any issues. I think that even without Robin's patch using intel_iommu=sp_off worked without errors, right? Casey
