Messages in this thread | | | Subject | Re: AMD Athlon bogus performance value causing RCU stalls? | From | Rob Prowel <> | Date | Wed, 26 Sep 2018 19:38:09 -0400 |
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On 09/23/18 17:19, Thomas Gleixner wrote: >> >> Other than RTFM, or please build a bunch of kernels from source on your slow >> machine, using differing config options to help track down the cause of >> this...any thoughts about a solution? > > Yes. This was decoded recently as an issue on 32bit due to a calculation > which is based on 'unsigned long' but requires to be 64bit wide. > > It's in the 4.18.8 stable kernel, which should be available from your > fedora repo anytime soon.
OK. Followup on AMD performance counter problem in 4.18.7
The Dell machine I was experiencing the problem on had a lot of ACPI issues. One of the invalid ACPI entries was for a system timer. dmesg suggests that the broken timer was used in calculating the Athlon performance value. So no, 32/64 bit math was not the issue.
ACPI=off in the kernel boot line fixed the issue completely. Machine still functions well as a file/web/postgresql dev server so it's all good.
tanks!
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