Messages in this thread | | | Date | Wed, 15 Aug 2018 13:24:25 -0400 (EDT) | From | Byron Stanoszek <> | Subject | Re: [PATCH 4.18 00/79] 4.18.1-stable review |
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Hi Greg & Thomas,
I'd like to report a regression in Linux 4.18.1 regarding the L1TF patches.
The kernel no longer thinks I have SMT enabled in the BIOS. This works fine in 4.18.0.
Not sure if this matters, but in my particular 4-core system, my third core is broken (core #2). So I must boot using "maxcpus=2" and then online the other cores & SMT threads at startup using:
echo 1 > /sys/devices/system/cpu/cpu3/online echo 1 > /sys/devices/system/cpu/cpu4/online echo 1 > /sys/devices/system/cpu/cpu5/online echo 1 > /sys/devices/system/cpu/cpu7/online
In 4.18.0, dmesg shows:
smpboot: Booting Node 0 Processor 3 APIC 0x6 smpboot: Booting Node 0 Processor 4 APIC 0x1 smpboot: Booting Node 0 Processor 5 APIC 0x3 smpboot: Booting Node 0 Processor 7 APIC 0x7
In 4.18.1, dmesg shows:
smpboot: Booting Node 0 Processor 3 APIC 0x6 smpboot: Booting Node 0 Processor 4 APIC 0x1 smpboot: CPU 4 is now offline smpboot: Booting Node 0 Processor 5 APIC 0x3 smpboot: CPU 5 is now offline smpboot: Booting Node 0 Processor 7 APIC 0x7 smpboot: CPU 7 is now offline
and I get an "Operation cancelled" error in the shell when trying to online 4, 5, and 7.
In 4.18.1, /sys/devices/system/cpu/smt/control says "notsupported".
- - -
A possible second regression is the following:
My CPU normally runs at 3600 MHz. I usually run my CPU at 2800 MHz to keep from overheating under full load (it is a fanless system). I do this by running "echo 1 > /sys/class/thermal/cooling_device5/cur_state", and confirm with "cat /proc/cpuinfo" (shows 2800).
This works in 4.18.0 but not in 4.18.1. I get no error from the "echo" command (and the state reads back as "1"), but the CPU remains running at 3600 MHz.
Thanks, -Byron
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