Bug 15157
Summary: | turbostat shows No Deep C-states, No deep P-states, limited Turbo mode - Supermicro X8DTN | ||
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Product: | ACPI | Reporter: | Len Brown (lenb) |
Component: | BIOS | Assignee: | acpi_bios |
Status: | CLOSED DOCUMENTED | ||
Severity: | normal | CC: | acpi-bugzilla |
Priority: | P1 | ||
Hardware: | All | ||
OS: | Linux | ||
Kernel Version: | 2.6.31.6 | Subsystem: | |
Regression: | No | Bisected commit-id: |
Description
Len Brown
2010-01-28 05:48:57 UTC
booting without maxcpus=1, this problem goes away. All the cores are able to enter c6 and get their frequency down to 1.6GHz for the short time they are in c0: CPU GHz TSC %c0 %c1 %c3 %c6 %pc3 %pc6 %pc7 0 1.60 2.80 0.16 0.23 0.00 99.61 0.00 98.95 0.00 1 1.60 2.80 0.08 0.09 0.00 99.83 0.00 98.95 0.00 2 1.60 2.80 0.01 0.02 0.00 99.96 0.00 98.95 0.00 3 1.63 2.80 0.01 0.03 0.00 99.96 0.00 98.95 0.00 4 1.60 2.80 0.01 0.02 0.00 99.98 0.00 98.96 0.00 5 1.60 2.80 0.06 0.13 0.00 99.81 0.00 98.96 0.00 6 1.58 2.80 0.01 0.02 0.00 99.97 0.00 98.96 0.00 7 1.60 2.80 0.01 0.02 0.00 99.98 0.00 98.96 0.00 8 1.60 2.80 0.04 0.35 0.00 99.61 0.00 98.95 0.00 9 1.60 2.80 0.02 0.15 0.00 99.83 0.00 98.95 0.00 10 1.60 2.80 0.01 0.03 0.00 99.96 0.00 98.95 0.00 11 1.59 2.80 0.01 0.03 0.00 99.96 0.00 98.95 0.00 12 1.57 2.80 0.01 0.02 0.00 99.98 0.00 98.96 0.00 13 1.60 2.80 0.04 0.15 0.00 99.81 0.00 98.96 0.00 14 1.63 2.80 0.01 0.02 0.00 99.97 0.00 98.96 0.00 15 1.60 2.80 0.01 0.01 0.00 99.98 0.00 98.96 0.00 When a cycle soaker is run, it is able to turbo-up to 3.2GHz as expected: CPU GHz TSC %c0 %c1 %c3 %c6 %pc3 %pc6 %pc7 0 3.20 2.80 1.91 6.24 3.63 88.22 0.00 0.00 0.00 1 3.19 2.80 0.05 99.95 0.00 0.00 0.00 0.00 0.00 2 2.90 2.80 0.02 0.09 84.97 14.92 0.00 0.00 0.00 3 2.49 2.80 0.01 0.09 84.98 14.92 0.00 0.00 0.00 4 1.60 2.80 0.14 0.21 0.00 99.65 0.00 0.00 0.00 5 1.60 2.80 0.05 0.10 0.00 99.85 0.00 0.00 0.00 6 1.63 2.80 0.01 0.02 0.00 99.98 0.00 0.00 0.00 7 1.60 2.80 0.01 0.02 0.00 99.98 0.00 0.00 0.00 8 3.20 2.80 2.24 5.91 3.63 88.22 0.00 0.00 0.00 9 3.20 2.80 99.99 0.01 0.00 0.00 0.00 0.00 0.00 10 2.53 2.80 0.01 0.10 84.98 14.91 0.00 0.00 0.00 11 2.51 2.80 0.01 0.09 84.98 14.92 0.00 0.00 0.00 12 1.60 2.80 0.07 0.29 0.00 99.65 0.00 0.00 0.00 13 1.60 2.80 0.04 0.10 0.00 99.85 0.00 0.00 0.00 14 1.60 2.80 0.01 0.02 0.00 99.98 0.00 0.00 0.00 15 1.60 2.80 0.01 0.01 0.00 99.98 0.00 0.00 0.00 The "maxcpus=1" power-management failure is due to a BIOS bug. The BIOS is supposed to put non-boot CPUSs into c6 so that if the OS does not start them, they will not interfere with power management. However, this BIOS is clearly leaving the non-boot CPUs in c1, which interferes with the power-management of the online cpus. This same symptom is seen when a kernel built for MAX_CPUS=8 is run on a 16-thread system (which is how I first noticed this problem). |