On Tue, Jul 09, 2024 at 11:37:07AM +0200, Jürgen Groß wrote: > > In both directories you can see the number of spurious events by looking > into the spurious_events file. > > In the end the question is why so many spurious events are happening. Finding > the reason might be hard, though.
Hopefully my comments on this drew your attention, yet lack of response suggests otherwise. I'm wondering whether this is an APIC misprogramming issue, similar to the x2APIC issue which was causing trouble with recent AMD processors. Trying to go after the Linux software RAID1, my current attempt is "iommu=debug iommu=no-intremap". I'm seeing *lots* of messages from spurious events in `xl dmesg`. So many I have a difficult time believing they are related to hardware I/O. In which case could the performance problem observed by Andrei Semenov be due to misprogramming of [x2]APIC triggering spurious events? If so this is actually rather serious as there is so much noise it is impossible to debug anything else. In other news logs are available for private (PGP) viewing. If one of the core developers has an appropriate AMD machine (IOMMUv2, Zen 1 or later; >=2 available SATA ports) I would send a pair of devices *known* to manifest the RAID1 issue. -- (\___(\___(\______ --=> 8-) EHM <=-- ______/)___/)___/) \BS ( | ehem+sig...@m5p.com PGP 87145445 | ) / \_CS\ | _____ -O #include <stddisclaimer.h> O- _____ | / _/ 8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445
