On 21.08.2021 18:25, Elliott Mitchell wrote: > ACPI C-state support might not see too much use, but it does see some. > > With Xen 4.11 and Linux kernel 4.19, I found higher C-states only got > enabled for physical cores for which Domain 0 had a corresponding vCPU. > On a machine where Domain 0 has 5 vCPUs, but 8 reported cores, the > additional C-states would only be enabled on cores 0-4. > > This can be worked around by giving Domain 0 vCPUs equal to cores, but > then offlining the extra vCPUs. I'm guessing this is a bug with the > Linux 4.19 xen_acpi_processor module. > > > > Appears Xen 4.14 doesn't work at all with Linux kernel 4.19's ACPI > C-state support. This combination is unable to enable higher C-states > on any core. Since Xen 4.14 and Linux 4.19 are *both* *presently* > supported it seems patch(es) are needed somewhere for this combination.
Hmm, having had observed the same quite some time ago, I thought I had dealt with these problems. Albeit surely not in Xen 4.11 or Linux 4.19. Any chance you could check up-to-date versions of both Xen and Linux (together)? Jan
