On Wed, 2008-04-02 at 18:17 +1100, Michael Ellerman wrote:
> On Wed, 2008-04-02 at 12:38 +0530, Kamalesh Babulal wrote:
> > Andrew Morton wrote:
> > > On Wed, 02 Apr 2008 11:55:36 +0530 Kamalesh Babulal <[EMAIL PROTECTED]>
> > > wrote:
> > >
> > >> Hi Andrew,
> > >>
> > >> The 2.6.25-rc8-mm1 kernel panic's while bootup on the power machine(s).
> > >>
> > >> [ 0.000000] ------------[ cut here ]------------
> > >> [ 0.000000] kernel BUG at arch/powerpc/mm/init_64.c:240!
> > >> [ 0.000000] Oops: Exception in kernel mode, sig: 5 [#1]
> > >> [ 0.000000] SMP NR_CPUS=32 NUMA PowerMac
> > >> [ 0.000000] Modules linked in:
> > >> [ 0.000000] NIP: c0000000003d1dcc LR: c0000000003d1dc4 CTR:
> > >> c00000000002b6ac
> > >> [ 0.000000] REGS: c00000000049b960 TRAP: 0700 Not tainted
> > >> (2.6.25-rc8-mm1-autokern1)
> > >> [ 0.000000] MSR: 9000000000021032 <ME,IR,DR> CR: 44000088 XER:
> > >> 20000000
> > >> [ 0.000000] TASK = c0000000003f9c90[0] 'swapper' THREAD:
> > >> c000000000498000 CPU: 0
> > >> [ 0.000000] GPR00: c0000000003d1dc4 c00000000049bbe0 c0000000004989d0
> > >> 0000000000000001
> > >> [ 0.000000] GPR04: d59aca40f0000000 000000000b000000 0000000000000010
> > >> 0000000000000000
> > >> [ 0.000000] GPR08: 0000000000000004 0000000000000001 c00000027e520800
> > >> c0000000004bf0f0
> > >> [ 0.000000] GPR12: c0000000004bf020 c0000000003fa900 0000000000000000
> > >> 0000000000000000
> > >> [ 0.000000] GPR16: 0000000000000000 0000000000000000 0000000000000000
> > >> 0000000000000000
> > >> [ 0.000000] GPR20: 0000000000000000 0000000000000000 0000000000000000
> > >> 4000000001400000
> > >> [ 0.000000] GPR24: 00000000017d64b0 c0000000003d6250 0000000000000000
> > >> c000000000504000
> > >> [ 0.000000] GPR28: 0000000000000000 cf000000001f8000 0000000001000000
> > >> cf00000000000000
> > >> [ 0.000000] NIP [c0000000003d1dcc] .vmemmap_populate+0xb8/0xf4
> > >> [ 0.000000] LR [c0000000003d1dc4] .vmemmap_populate+0xb0/0xf4
> > >> [ 0.000000] Call Trace:
> > >> [ 0.000000] [c00000000049bbe0] [c0000000003d1dc4]
> > >> .vmemmap_populate+0xb0/0xf4 (unreliable)
> > >> [ 0.000000] [c00000000049bc70] [c0000000003d2ee8]
> > >> .sparse_mem_map_populate+0x38/0x60
> > >> [ 0.000000] [c00000000049bd00] [c0000000003c242c]
> > >> .sparse_early_mem_map_alloc+0x54/0x94
> > >> [ 0.000000] [c00000000049bd90] [c0000000003c250c]
> > >> .sparse_init+0xa0/0x20c
> > >> [ 0.000000] [c00000000049be50] [c0000000003ab7d0]
> > >> .setup_arch+0x1ac/0x218
> > >> [ 0.000000] [c00000000049bee0] [c0000000003a36ac]
> > >> .start_kernel+0xe0/0x3fc
> > >> [ 0.000000] [c00000000049bf90] [c000000000008594]
> > >> .start_here_common+0x54/0xc0
> > >> [ 0.000000] Instruction dump:
> > >> [ 0.000000] 7fe3fb78 7ca02a14 4082000c 3860fff4 4800003c e92289c8
> > >> e96289c0 e9090002
> > >> [ 0.000000] e8eb0002 4bc575cd 60000000 78630fe0 <0b030000> 7ffff214
> > >> 7fbfe840 7fe3fb78
> > >> [ 0.000000] ---[ end trace 31fd0ba7d8756001 ]---
> > >> [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle
> > >> task!
> > >>
> > >
> > > int __meminit vmemmap_populate(struct page *start_page,
> > > unsigned long nr_pages, int node)
> > > {
> > > unsigned long mode_rw;
> > > unsigned long start = (unsigned long)start_page;
> > > unsigned long end = (unsigned long)(start_page + nr_pages);
> > > unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift;
> > >
> > > mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
> > >
> > > /* Align to the page size of the linear mapping. */
> > > start = _ALIGN_DOWN(start, page_size);
> > >
> > > for (; start < end; start += page_size) {
> > > int mapped;
> > > void *p;
> > >
> > > if (vmemmap_populated(start, page_size))
> > > continue;
> > >
> > > p = vmemmap_alloc_block(page_size, node);
> > > if (!p)
> > > return -ENOMEM;
> > >
> > > pr_debug("vmemmap %08lx allocated at %p, physical %08lx.\n",
> > > start, p, __pa(p));
> > >
> > > mapped = htab_bolt_mapping(start, start + page_size,
> > > __pa(p), mode_rw, mmu_linear_psize,
> > > mmu_kernel_ssize);
> > > =====> BUG_ON(mapped < 0);
> > > }
> > >
> > > return 0;
> > > }
> > >
> > > Beats me. pseries? Badari has been diddling with the bolted memory code
> > > in git-powerpc...
> >
> > One of the machines is the Power5 and another is PowerMac G5, on which the
> > same kernel panic is seen.
>
> Can you enable DEBUG_LOW in arch/powerpc/platforms/pseries/lpar.c, that
> should show what's happening in hpte_insert().
>
> cheers
>
Okay. Found it.
Root cause is:
mm-make-mem_map-allocation-continuous.patch
and its friends in -mm.
You have to call sparse_init_one_section() on each pmap and usemap
as we allocate - since valid_section() depends on it (which is needed
by vmemmap_populate() to check if the section is populated or not).
On ppc, we need to call htab_bolted_mapping() on each section and
we need to skip existing sections.
These patches tried to group all allocations together and then later
calls sparse_init_one_section() - which is not good :(
Please let me know, if its doesn't make sense - I will try to explain
better :)
Thanks,
Badari
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