On 4/10/2021 5:03 PM, David Coe wrote: > Results for AMD Ryzen 4700U running Ubuntu 21.04β kernel 5.11.0-13 > > $ sudo dmesg | grep IOMMU > [ 0.490352] pci 0000:00:00.2: AMD-Vi: IOMMU performance counters supported > [ 0.491985] pci 0000:00:00.2: AMD-Vi: Found IOMMU cap 0x40 > [ 0.493732] perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 > counters/bank). > [ 0.793259] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel <jroe...@suse.de> > > .... > > $ sudo perf stat -e 'amd_iommu_0/cmd_processed/, > amd_iommu_0/cmd_processed_inv/, amd_iommu_0/ign_rd_wr_mmio_1ff8h/, > amd_iommu_0/int_dte_hit/, amd_iommu_0/int_dte_mis/, amd_iommu_0/mem_dte_hit/, > amd_iommu_0/mem_dte_mis/, amd_iommu_0/mem_iommu_tlb_pde_hit/, > amd_iommu_0/mem_iommu_tlb_pde_mis/, amd_iommu_0/mem_iommu_tlb_pte_hit/, > amd_iommu_0/mem_iommu_tlb_pte_mis/, amd_iommu_0/mem_pass_excl/, > amd_iommu_0/mem_pass_pretrans/, amd_iommu_0/mem_pass_untrans/, > amd_iommu_0/mem_target_abort/, > amd_iommu_0/mem_trans_total/, amd_iommu_0/page_tbl_read_gst/, > amd_iommu_0/page_tbl_read_nst/, amd_iommu_0/page_tbl_read_tot/, > amd_iommu_0/smi_blk/, amd_iommu_0/smi_recv/, amd_iommu_0/tlb_inv/, > amd_iommu_0/vapic_int_guest/, amd_iommu_0/vapic_int_non_guest/' sleep 10 > > Performance counter stats for 'system wide': > > 12 amd_iommu_0/cmd_processed/ (33.28%) > 6 amd_iommu_0/cmd_processed_inv/ (33.32%) > 0 amd_iommu_0/ign_rd_wr_mmio_1ff8h/ (33.36%) > 290 amd_iommu_0/int_dte_hit/ (33.40%) > 20 amd_iommu_0/int_dte_mis/ (33.46%) > 391 amd_iommu_0/mem_dte_hit/ (33.49%) > 3,720 amd_iommu_0/mem_dte_mis/ (33.49%) > 44 amd_iommu_0/mem_iommu_tlb_pde_hit/ (33.46%) > 810 amd_iommu_0/mem_iommu_tlb_pde_mis/ (33.45%) > 35 amd_iommu_0/mem_iommu_tlb_pte_hit/ (33.41%) > 746 amd_iommu_0/mem_iommu_tlb_pte_mis/ (33.37%) > 0 amd_iommu_0/mem_pass_excl/ (33.32%) > 0 amd_iommu_0/mem_pass_pretrans/ (33.28%) > 0 amd_iommu_0/mem_pass_untrans/ (33.28%) > 0 amd_iommu_0/mem_target_abort/ (33.27%) > 715 amd_iommu_0/mem_trans_total/ (33.27%) > 0 amd_iommu_0/page_tbl_read_gst/ (33.28%) > 36 amd_iommu_0/page_tbl_read_nst/ (33.27%) > 36 amd_iommu_0/page_tbl_read_tot/ (33.27%) > 0 amd_iommu_0/smi_blk/ (33.28%) > 0 amd_iommu_0/smi_recv/ (33.26%) > 0 amd_iommu_0/tlb_inv/ (33.23%) > 0 amd_iommu_0/vapic_int_guest/ (33.24%) > 366 amd_iommu_0/vapic_int_non_guest/ (33.27%) > > The immediately obvious difference is the with the enormous count seen on > mem_dte_mis on the older Ryzen 2400G. Will do some RTFM but anyone with > comments and insight? > > 841,689,151,202,939 amd_iommu_0/mem_dte_mis/ (33.44%) > > Otherwise, all seems to running smoothly (especially for a distribution still > in β). Bravo and many thanks all! > That doesn't look correct. Lemme do some more investigation also.
Thanks, Suravee -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1917203 Title: AMD-Vi: Unable to read/write to IOMMU perf counter Status in linux package in Ubuntu: In Progress Bug description: This boot warning (concealed by grub not taking over the fbcon console on a solo installation but always present on a multi-boot) has been bothering Linux users of AMD Ryzen machines for some time. The problem is currently under discussion at kernel level <https://bugzilla.kernel.org/show_bug.cgi?id=201753>. One solution proposed by Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> <https://lkml.org/lkml/2021/2/8/486> works but inserts a boot-up delay of (at least) 100 msec. A second option by Alexander Monakov <amona...@ispras.ru> <https://bugzilla.kernel.org/show_bug.cgi?id=201753> also works but inserts no delay and more-or-less just moves one line of code. I've tried both solutions with kernel rebuilds for both Breezy kernel 5.8.18 and Hirsute kernel 5.10.11 and both work on my AMD Ryzen 2400G. Could I encourage your kernel experts to evaluate the situation (I think SuSE folk already are). My suggestion (as a humble user :-) ) would be to fold Alex's simple patch into your own list of kernel tweeks and get the correction out with the upcoming Hirsute release. Best regards and all respect! To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1917203/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
