Messages in this thread Patch in this message | | | Date | Tue, 20 Sep 2005 10:30:48 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: x86-64 bad pmds in 2.6.11.6 |
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On Tue, 20 Sep 2005, Charles McCreary wrote: > > Another datapoint for this thread. The box spewing the bad pmds messages is a > dual opteron 246 on a TYAN S2885 Thunder K8W motherboard. Kernel is > 2.6.11.4-20a-smp.
This is quite possibly the result of an Opteron errata (tlb flush filtering is broken on SMP) that we worked around as of 2.6.14-rc4.
So either just try 2.6.14-rc2, or try the appended patch (it has since been confirmed by many more people).
Linus
--- diff-tree bc5e8fdfc622b03acf5ac974a1b8b26da6511c99 (from 61ffcafafb3d985e1ab8463be0187b421614775c) Author: Linus Torvalds <torvalds@g5.osdl.org> Date: Sat Sep 17 15:41:04 2005 -0700
x86-64/smp: fix random SIGSEGV issues They seem to have been due to AMD errata 63/122; the fix is to disable TLB flush filtering in SMP configurations. Confirmed to fix the problem by Andrew Walrond <andrew@walrond.org> [ Let's see if we'll have a better fix eventually, this is the Q&D "let's get this fixed and out there" version ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -831,11 +831,26 @@ static void __init amd_detect_cmp(struct #endif } +#define HWCR 0xc0010015 + static int __init init_amd(struct cpuinfo_x86 *c) { int r; int level; +#ifdef CONFIG_SMP + unsigned long value; + + // Disable TLB flush filter by setting HWCR.FFDIS: + // bit 6 of msr C001_0015 + // + // Errata 63 for SH-B3 steppings + // Errata 122 for all(?) steppings + rdmsrl(HWCR, value); + value |= 1 << 6; + wrmsrl(HWCR, value); +#endif + /* Bit 31 in normal CPUID used for nonstandard 3DNow ID; 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */ clear_bit(0*32+31, &c->x86_capability); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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