Re: Success kernel-243pre8-SMP(patch)(Re: spin_lock problem in recent kernel

[Tom Gall <gall@rochcivictheatre.org>]

Hi Kaoru,

  I tried your patch on my 2 way Power3 Model 270 RS/6000 just before I
left but didn't have enough time to write this note until now.

  Your patch amazingly booted my box quite a bit further... it still
dies for me but in a new and interesting way, that doesn't appear to be
related to the page_table_lock. (Token Ring and shared memory
...sigh...)

  The part that REALLY REALLY bothers me tho is why does this patch
work? I *HAVE* CONFIG_SMP on... least I think I do... there's two
penguins on my screen ... two processors grinding away ... that's
CONFIG_SMP right??? I'm not losing my mind am I?

  So assuming that CONFIG_SMP is on, this patch shouldn't yeild anything
different what so ever from a codegen perspective with or without the
patch for an SMP kernel build. It doesn't make sense.

Kaoru Fukui wrote:
>
> Many thanks Tom,
>
> I have had a success for kernel-2.4.3.pre8-SMP on Dual G4.
> This kernel needs the patch.
>
> Kernel Guys, Please look the patch
>
> I will be able to upload this binary kernel into my directory tomorrow.
>
> Kaoru
> -------- this patch is needed for SMP kernel-2.4.3.pre8  ---------
>
> diff -urN base/arch/ppc/mm/init.c fixed/arch/ppc/mm/init.c
> --- base/arch/ppc/mm/init.c     Thu Mar 29 06:02:35 2001
> +++ fixed/arch/ppc/mm/init.c    Fri Mar 30 05:51:16 2001
> @@ -437,12 +437,15 @@
>         /*
>          * Should check if it is a candidate for a BAT mapping
>          */
> -
> +#ifndef CONFIG_SMP
>         spin_lock(&init_mm.page_table_lock);
> +#endif
>         err = 0;
>         for (i = 0; i < size && err == 0; i += PAGE_SIZE)
>                 err = map_page(v+i, p+i, flags);
> +#ifndef CONFIG_SMP
>         spin_unlock(&init_mm.page_table_lock);
> +#endif
>         if (err) {
>                 if (mem_init_done)
>                         vfree((void *)v);
> diff -urN base/mm/memory.c fixed/mm/memory.c
> --- base/mm/memory.c    Thu Mar 29 09:22:35 2001
> +++ fixed/mm/memory.c   Fri Mar 30 05:52:17 2001
> @@ -1320,9 +1320,13 @@
>                 /* "fast" allocation can happen without dropping the lock.. */
>                 new = pte_alloc_one_fast(address);
>                 if (!new) {
> +#ifndef CONFIG_SMP
>                         spin_unlock(&mm->page_table_lock);
> +#endif
>                         new = pte_alloc_one(address);
> +#ifndef CONFIG_SMP
>                         spin_lock(&mm->page_table_lock);
> +#endif
>                         if (!new)
>                                 return NULL;
>
> ---------- END -------------
>
> > > This is booing message when kernel-2.4.3pre8-SMP.
> > >
> > > <snip>
> > > TCP: Hash tables configured (established 8192 bind 8192)
> > > ip_conntrack(2048 buckets,16384 max)
> > > _spin_lock(c02cc470) CPU# 1 NIP c0033404 holder: cpu 1 pc C002B384
> > > _spin_lock(c02ce740) CPU# 0 NIP c0015890 holder: cpu 1 pc C0015890
>
> >   Can you look at your system.map for that kernel and tell me what is at
> > addresses:
>
> > This is getton  data from system.map
>
> > c00153b0 T schedule_tail
> > <C001589>
> > c0015a4c T __wake_up
> > <snip>
> > c002b28c T pte_alloc
> > <C002b384>
> > c002b3d8 T make_pages_present
> > <snip>
> > c02cc42c D init_mm
> > <c02cc470>
> > c02cc4d0 D init_task_union
> > <snip>
> > c02ce738 d null_pci_ops
> > <c02ce740>
> > c02ce750 D kernel_flag
> >
>

--
Regards,

Tom

--------------------------------------------------------------
Linux Guy             "My heart is human, my blood is boiling,
gall@rochcivictheatre.org    my brain IBM" -- Mr Roboto, Styxx

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