David, On 4/14/2021 10:33 PM, David Coe wrote: > Hi Suravee! > > I've re-run your revert+update patch on Ubuntu's latest kernel 5.11.0-14 > partly to check my mailer's 'mangling' hadn't also reached the code! > > There are 3 sets of results in the attachment, all for the Ryzen 2400G. The > as-distributed kernel already incorporates your IOMMU RFCv3 patch. > > A. As-distributed kernel (cold boot) > >5 retries, so no IOMMU read/write capability, no amd_iommu events. > > B. As-distributed kernel (warm boot) > <5 retries, amd_iommu running stats show large numbers as before. > > C. Revert+Update kernel > amd_iommu events listed and also show large hit/miss numbers. > > In due course, I'll load the new (revert+update) kernel on the 4700G but > won't overload your mail-box unless something unusual turns up. > > Best regards, >
For the Ryzen 2400G, could you please try with: - 1 event at a time - Not more than 8 events (On your system, it has 2 banks x 4 counters/bank. I am trying to see if this issue might be related to the counters multiplexing). 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 <[email protected]> <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 <[email protected]> <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 : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
