Re: [PATCH] Fix sparsemem on Cell

Arnd Bergmann
2006-12-18T22:54:45Z

On Saturday 16 December 2006 09:03, KAMEZAWA Hiroyuki wrote:
> @@ -273,10 +284,13 @@
> if (ret)
> goto error;
> }
> + atomic_inc(&memory_hotadd_count);
>
> /* call arch's memory hotadd */
> ret = arch_add_memory(nid, start, size);
>
> + atomic_dec(&memory_hotadd_count);
> +
> if (ret < 0)
> goto error;
>

This also doesn't fix the problem on cell, since the time when the bug
happens, we're not calling through this function, or arch_add_memory,
at all, but rather invoke __add_pages directly. As BenH already mentioned,
we shouldn't do really call __add_pages at all.

Let me attempt another fix that might address all cases. This is completely
untested as of now, but also addresses Dave's latest comment.

Arnd <><

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 1a3d8a2..723d220 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -543,7 +543,7 @@ virtual_memmap_init (u64 start, u64 end, void *arg)

if (map_start < map_end)
memmap_init_zone((unsigned long)(map_end - map_start),
- args->nid, args->zone, page_to_pfn(map_start));
+ args->nid, args->zone, page_to_pfn(map_start), 1);
return 0;
}

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 7f2944d..1e52cd1 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -61,7 +61,7 @@ void memmap_init(unsigned long size, int nid, unsigned long zone,

if (map_start < map_end)
memmap_init_zone((unsigned long)(map_end - map_start),
- nid, zone, page_to_pfn(map_start));
+ nid, zone, page_to_pfn(map_start), 1);
}
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a17b147..6d85068 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -978,7 +978,7 @@ extern int early_pfn_to_nid(unsigned long pfn);
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
extern void set_dma_reserve(unsigned long new_dma_reserve);
-extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
+extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long, int);
extern void setup_per_zone_pages_min(void);
extern void mem_init(void);
extern void show_mem(void);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0c055a0..16c9930 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -71,7 +71,7 @@ static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
if (ret < 0)
return ret;
}
- memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
+ memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn, 0);
return 0;
}

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8c1a116..60d1ac8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1953,17 +1953,19 @@ static inline unsigned long wait_table_bits(unsigned long size)
* done. Non-atomic initialization, single-pass.
*/
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
- unsigned long start_pfn)
+ unsigned long start_pfn, int early)
{
struct page *page;
unsigned long end_pfn = start_pfn + size;
unsigned long pfn;

for (pfn = start_pfn; pfn < end_pfn; pfn++) {
- if (!early_pfn_valid(pfn))
- continue;
- if (!early_pfn_in_nid(pfn, nid))
- continue;
+ if (early) {
+ if (!early_pfn_valid(pfn))
+ continue;
+ if (!early_pfn_in_nid(pfn, nid))
+ continue;
+ }
page = pfn_to_page(pfn);
set_page_links(page, zone, nid, pfn);
init_page_count(page);
@@ -1990,7 +1992,7 @@ void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,

#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
- memmap_init_zone((size), (nid), (zone), (start_pfn))
+ memmap_init_zone((size), (nid), (zone), (start_pfn), 1)
#endif

static int __cpuinit zone_batchsize(struct zone *zone)