8.0RC2 amd64 - kernel panic running make buildworld

[Kai Gallasch]

Am Fri, 13 Nov 2009 10:08:45 +0200
schrieb Andriy Gapon <avg at icyb.net.ua>:

> on 12/11/2009 20:59 Kai Gallasch said the following:
> > sonnenkraft:~ # MCA: CPU 4 UNCOR PCC OVER DTLB L1 error

> Kai,
> I have a hunch, could you please try the following _sledgehammer_
> patch (only kernel build/install is needed):
> diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
> index 44b71f3..a456609 100644
> --- a/sys/amd64/amd64/pmap.c
> +++ b/sys/amd64/amd64/pmap.c
> @@ -2981,6 +2981,7 @@ setpte:
>  	 * Map the superpage.
>  	 */
>  	pde_store(pde, PG_PS | newpde);
> +	pmap_invalidate_all(pmap);
> 
>  	pmap_pde_promotions++;
>  	CTR2(KTR_PMAP, "pmap_promote_pde: success for va %#lx"
> 
> This will slow down an act of promotion to a superpage, but should
> not have any visible impact on overall performance.

Andriy,

I tried the patch with vm.pmap.pg_ps_enabled="1" , hw.mca.enabled="1"
, rebuilt the kernel (although normally I never build kernels on Friday
13th :-) and ran buildworld -j8 for five times in a row. No sign of a
machine check exception, no reboot.

--Kai.



-- 
The final screw holding up a rackmount server is always possessed by
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