2008-06-16 10:33:18

by Andy Whitcroft

[permalink] [raw]
Subject: Re: [Patch 003/005](memory hotplug) make alloc_bootmem_section()

On Mon, Apr 07, 2008 at 09:47:29PM +0900, Yasunori Goto wrote:
> alloc_bootmem_section() can allocate specified section's area.
> This is used for usemap to keep same section with pgdat by later patch.
>
> Signed-off-by: Yasunori Goto <[email protected]>
>
> ---
> include/linux/bootmem.h | 2 ++
> mm/bootmem.c | 31 +++++++++++++++++++++++++++++++
> 2 files changed, 33 insertions(+)
>
> Index: current/include/linux/bootmem.h
> ===================================================================
> --- current.orig/include/linux/bootmem.h 2008-04-07 19:18:44.000000000 +0900
> +++ current/include/linux/bootmem.h 2008-04-07 19:30:08.000000000 +0900
> @@ -101,6 +101,8 @@
> extern void free_bootmem_node(pg_data_t *pgdat,
> unsigned long addr,
> unsigned long size);
> +extern void *alloc_bootmem_section(unsigned long size,
> + unsigned long section_nr);
>
> #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
> #define alloc_bootmem_node(pgdat, x) \
> Index: current/mm/bootmem.c
> ===================================================================
> --- current.orig/mm/bootmem.c 2008-04-07 19:18:44.000000000 +0900
> +++ current/mm/bootmem.c 2008-04-07 19:30:08.000000000 +0900
> @@ -540,6 +540,37 @@
> return __alloc_bootmem(size, align, goal);
> }
>
> +#ifdef CONFIG_SPARSEMEM
> +void * __init alloc_bootmem_section(unsigned long size,
> + unsigned long section_nr)
> +{
> + void *ptr;
> + unsigned long limit, goal, start_nr, end_nr, pfn;
> + struct pglist_data *pgdat;
> +
> + pfn = section_nr_to_pfn(section_nr);
> + goal = PFN_PHYS(pfn);
> + limit = PFN_PHYS(section_nr_to_pfn(section_nr + 1)) - 1;
> + pgdat = NODE_DATA(early_pfn_to_nid(pfn));
> + ptr = __alloc_bootmem_core(pgdat->bdata, size, SMP_CACHE_BYTES, goal,
> + limit);
> +
> + if (!ptr)
> + return NULL;
> +
This also indicates a failure allocating within the section, and yet we
do not report it here.

> + start_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr)));
> + end_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr) + size));
> + if (start_nr != section_nr || end_nr != section_nr) {
> + printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
> + section_nr);
> + free_bootmem_core(pgdat->bdata, __pa(ptr), size);

But we do here. I think we should report both if this is worth
reporting.

> + ptr = NULL;
> + }
> +
> + return ptr;
> +}
> +#endif
> +
> #ifndef ARCH_LOW_ADDRESS_LIMIT
> #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
> #endif

-apw


2008-06-16 13:28:21

by Yasunori Goto

[permalink] [raw]
Subject: Re: [Patch 003/005](memory hotplug) make alloc_bootmem_section()

> On Mon, Apr 07, 2008 at 09:47:29PM +0900, Yasunori Goto wrote:
> > alloc_bootmem_section() can allocate specified section's area.
> > This is used for usemap to keep same section with pgdat by later patch.
> >
> > Signed-off-by: Yasunori Goto <[email protected]>
> >
> > ---
> > include/linux/bootmem.h | 2 ++
> > mm/bootmem.c | 31 +++++++++++++++++++++++++++++++
> > 2 files changed, 33 insertions(+)
> >
> > Index: current/include/linux/bootmem.h
> > ===================================================================
> > --- current.orig/include/linux/bootmem.h 2008-04-07 19:18:44.000000000 +0900
> > +++ current/include/linux/bootmem.h 2008-04-07 19:30:08.000000000 +0900
> > @@ -101,6 +101,8 @@
> > extern void free_bootmem_node(pg_data_t *pgdat,
> > unsigned long addr,
> > unsigned long size);
> > +extern void *alloc_bootmem_section(unsigned long size,
> > + unsigned long section_nr);
> >
> > #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
> > #define alloc_bootmem_node(pgdat, x) \
> > Index: current/mm/bootmem.c
> > ===================================================================
> > --- current.orig/mm/bootmem.c 2008-04-07 19:18:44.000000000 +0900
> > +++ current/mm/bootmem.c 2008-04-07 19:30:08.000000000 +0900
> > @@ -540,6 +540,37 @@
> > return __alloc_bootmem(size, align, goal);
> > }
> >
> > +#ifdef CONFIG_SPARSEMEM
> > +void * __init alloc_bootmem_section(unsigned long size,
> > + unsigned long section_nr)
> > +{
> > + void *ptr;
> > + unsigned long limit, goal, start_nr, end_nr, pfn;
> > + struct pglist_data *pgdat;
> > +
> > + pfn = section_nr_to_pfn(section_nr);
> > + goal = PFN_PHYS(pfn);
> > + limit = PFN_PHYS(section_nr_to_pfn(section_nr + 1)) - 1;
> > + pgdat = NODE_DATA(early_pfn_to_nid(pfn));
> > + ptr = __alloc_bootmem_core(pgdat->bdata, size, SMP_CACHE_BYTES, goal,
> > + limit);
> > +
> > + if (!ptr)
> > + return NULL;
> > +
> This also indicates a failure allocating within the section, and yet we
> do not report it here.
>
> > + start_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr)));
> > + end_nr = pfn_to_section_nr(PFN_DOWN(__pa(ptr) + size));
> > + if (start_nr != section_nr || end_nr != section_nr) {
> > + printk(KERN_WARNING "alloc_bootmem failed on section %ld.\n",
> > + section_nr);
> > + free_bootmem_core(pgdat->bdata, __pa(ptr), size);
>
> But we do here. I think we should report both if this is worth
> reporting.

Here is already removed from newest -mm.
(Bootmem code is rewritten by Johannes Weiner recently.)
Please check the newest -mm code.

--
Yasunori Goto