Re: 8.0RC2 amd64 - kernel panic running make buildworld

on 14/11/2009 11:36 Andriy Gapon said the following:
> on 14/11/2009 03:21 Kai Gallasch said the following:
>> Hi. The patch did help for surviving a makeworld.
>>
>> But now I have another machine check exception with this server. It
>> happened with your patch active, and vm.pmap.pg_ps_enabled="1". I
>> copied data from a remote server by NFS mount to the instable server.
>> Destination was a local ZFS filesystem.
>>
>> ----------------
>>
>> sonnenkraft:~ # MCA: CPU 7 UNCOR PCC OVER DTLB L1 error
>> MCA: Address 0xff800d860000
> 
> It's interesting because the same happened to me too, only in my case it was
> zpool scrub that triggered it.
> I will try to look into this further.
> 

Kai,

the latest patch in the works, it's against a clean tree:

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 44b71f3..ff35eb9 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
_at__at_ -2365,6 +2365,9 _at__at_ pmap_demote_pde
 	 * the read above and the store below.
 	 */
 	pde_store(pde, newpde);	
+	pmap_invalidate_page(pmap, va);
+	clflush((vm_offset_t)vtopde(va));
+	mfence();

 	/*
 	 * Invalidate a stale recursive mapping of the page table page.
_at__at_ -2981,6 +2984,11 _at__at_ setpte:
 	 * Map the superpage.
 	 */
 	pde_store(pde, PG_PS | newpde);
+	pmap_invalidate_range(pmap, va & ~PDRMASK, (va & ~PDRMASK) + NBPDR);
+	clflush((vm_offset_t)vtopde(va));
+	mfence();
+	if (va >= VM_MAXUSER_ADDRESS)
+		pmap_invalidate_page(pmap, (vm_offset_t)vtopte(va));

 	pmap_pde_promotions++;
 	CTR2(KTR_PMAP, "pmap_promote_pde: success for va %#lx"


-- 
Andriy Gapon