Re: Fix for SLUB? (was: Fwd: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards)

[Michael Schmitz <schmitzmic@googlemail.com>]

I'll check this out - might well be the correct fix for our problems.

Cheers,

  Michael


On Thu, Apr 21, 2011 at 8:19 PM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> ---------- Forwarded message ----------
> From: David Rientjes <rientjes@google.com>
> Date: Thu, Apr 21, 2011 at 01:12
> Subject: Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards
> To: James Bottomley <James.Bottomley@hansenpartnership.com>
> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, Pekka Enberg
> <penberg@kernel.org>, Christoph Lameter <cl@linux.com>, Michal Hocko
> <mhocko@suse.cz>, Andrew Morton <akpm@linux-foundation.org>, Hugh
> Dickins <hughd@google.com>, linux-mm@kvack.org, LKML
> <linux-kernel@vger.kernel.org>, linux-parisc@vger.kernel.org, Ingo
> Molnar <mingo@elte.hu>, x86 maintainers <x86@kernel.org>
>
>
> On Wed, 20 Apr 2011, James Bottomley wrote:
>
>> > This is probably because the parisc's DISCONTIGMEM memory ranges don't
>> > have bits set in N_NORMAL_MEMORY.
>> >
>> > diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
>> > --- a/arch/parisc/mm/init.c
>> > +++ b/arch/parisc/mm/init.c
>> > @@ -266,8 +266,10 @@ static void __init setup_bootmem(void)
>> >     }
>> >     memset(pfnnid_map, 0xff, sizeof(pfnnid_map));
>> >
>> > -   for (i = 0; i < npmem_ranges; i++)
>> > +   for (i = 0; i < npmem_ranges; i++) {
>> > +           node_set_state(i, N_NORMAL_MEMORY);
>> >             node_set_online(i);
>> > +   }
>> >  #endif
>>
>> Yes, this seems to be the missing piece that gets it to boot.  We really
>> need this in generic code, unless someone wants to run through all the
>> other arch's doing it ...
>>
>
> Looking at all other architectures that allow ARCH_DISCONTIGMEM_ENABLE, we
> already know x86 is fine, avr32 disables ARCH_DISCONTIGMEM_ENABLE entirely
> because its code only brings online node 0, and tile already sets the bit
> in N_NORMAL_MEMORY correctly when bringing a node online, probably because
> it was introduced after the various node state masks were added in
> 7ea1530ab3fd back in October 2007.
>
> So we're really only talking about alpha, ia64, m32r, m68k, and mips and
> it only seems to matter when using CONFIG_SLUB, which isn't surprising
> when greping for it:
>
>        $ grep -r N_NORMAL_MEMORY mm/*
>        mm/memcontrol.c:        if (!node_state(node, N_NORMAL_MEMORY))
>        mm/memcontrol.c:                if (!node_state(node, N_NORMAL_MEMORY))
>        mm/page_alloc.c:        [N_NORMAL_MEMORY] = { { [0] = 1UL } },
>        mm/page_alloc.c:
> node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:              for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:              for_each_node_state(node, N_NORMAL_MEMORY) {
>        mm/slub.c:      for_each_node_state(node, N_NORMAL_MEMORY)
>
> Those memory controller occurrences only result in it passing a node id of
> -1 to kmalloc_node() which means no specific node target, and that's fine
> for DISCONTIGMEM since we don't care about any proximity between memory
> ranges.
>
> This should fix the remaining architectures so they can use CONFIG_SLUB,
> but I hope it can be tested by the individual arch maintainers like you
> did for parisc.
>
> diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c
> --- a/arch/alpha/mm/numa.c
> +++ b/arch/alpha/mm/numa.c
> @@ -245,6 +245,7 @@ setup_memory_node(int nid, void *kernel_end)
>                        bootmap_size, BOOTMEM_DEFAULT);
>        printk(" reserving pages %ld:%ld\n", bootmap_start,
> bootmap_start+PFN_UP(bootmap_size));
>
> +       node_set_state(nid, N_NORMAL_MEMORY);
>        node_set_online(nid);
>  }
>
> diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
> --- a/arch/ia64/mm/discontig.c
> +++ b/arch/ia64/mm/discontig.c
> @@ -573,6 +573,8 @@ void __init find_memory(void)
>                                  map>>PAGE_SHIFT,
>                                  bdp->node_min_pfn,
>                                  bdp->node_low_pfn);
> +               if (node_present_pages(node))
> +                       node_set_state(node, N_NORMAL_MEMORY);
>        }
>
>        efi_memmap_walk(filter_rsvd_memory, free_node_bootmem);
> diff --git a/arch/m32r/kernel/setup.c b/arch/m32r/kernel/setup.c
> --- a/arch/m32r/kernel/setup.c
> +++ b/arch/m32r/kernel/setup.c
> @@ -247,7 +247,9 @@ void __init setup_arch(char **cmdline_p)
>
>  #ifdef CONFIG_DISCONTIGMEM
>        nodes_clear(node_online_map);
> +       node_set_state(0, N_NORMAL_MEMORY);     /* always has memory */
>        node_set_online(0);
> +       node_set_state(1, N_NORMAL_MEMORY);     /* always has memory */
>        node_set_online(1);
>  #endif /* CONFIG_DISCONTIGMEM */
>
> diff --git a/arch/m68k/mm/init_mm.c b/arch/m68k/mm/init_mm.c
> --- a/arch/m68k/mm/init_mm.c
> +++ b/arch/m68k/mm/init_mm.c
> @@ -59,6 +59,8 @@ void __init m68k_setup_node(int node)
>        }
>  #endif
>        pg_data_map[node].bdata = bootmem_node_data + node;
> +       if (node_present_pages(node))
> +               node_set_state(node, N_NORMAL_MEMORY);
>        node_set_online(node);
>  }
>
> diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
> --- a/arch/mips/sgi-ip27/ip27-memory.c
> +++ b/arch/mips/sgi-ip27/ip27-memory.c
> @@ -471,6 +471,8 @@ void __init paging_init(void)
>
>                if (end_pfn > max_low_pfn)
>                        max_low_pfn = end_pfn;
> +               if (end_pfn > start_pfn)
> +                       node_set_state(node, N_NORMAL_MEMORY);
>        }
>        zones_size[ZONE_NORMAL] = max_low_pfn;
>        free_area_init_nodes(zones_size);
> --
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>
>
> --
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>