Re: [PATCH] Fix sparsemem on Cell

[Arnd Bergmann <arnd@arndb.de>]

On Saturday 16 December 2006 09:03, KAMEZAWA Hiroyuki wrote:
> @@ -273,10 +284,13 @@
> =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0if (ret)
> =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0g=
oto error;
> =A0=A0=A0=A0=A0=A0=A0=A0}
> +=A0=A0=A0=A0=A0=A0=A0atomic_inc(&memory_hotadd_count);
> =A0
> =A0=A0=A0=A0=A0=A0=A0=A0/* call arch's memory hotadd */
> =A0=A0=A0=A0=A0=A0=A0=A0ret =3D arch_add_memory(nid, start, size);
> =A0
> +=A0=A0=A0=A0=A0=A0=A0atomic_dec(&memory_hotadd_count);
> +
> =A0=A0=A0=A0=A0=A0=A0=A0if (ret < 0)
> =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0goto error;
> =A0

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
=2D-- 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)
=20
 	if (map_start < map_end)
 		memmap_init_zone((unsigned long)(map_end - map_start),
=2D				 args->nid, args->zone, page_to_pfn(map_start));
+				 args->nid, args->zone, page_to_pfn(map_start), 1);
 	return 0;
 }
=20
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 7f2944d..1e52cd1 100644
=2D-- 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 lo=
ng zone,
=20
 		if (map_start < map_end)
 			memmap_init_zone((unsigned long)(map_end - map_start),
=2D					 nid, zone, page_to_pfn(map_start));
+					 nid, zone, page_to_pfn(map_start), 1);
 	}
 }
=20
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a17b147..6d85068 100644
=2D-- 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);
=2Dextern void memmap_init_zone(unsigned long, int, unsigned long, unsigned=
 long);
+extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned l=
ong, 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
=2D-- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -71,7 +71,7 @@ static int __add_zone(struct zone *zone, unsigned long ph=
ys_start_pfn)
 		if (ret < 0)
 			return ret;
 	}
=2D	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;
 }
=20
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8c1a116..60d1ac8 100644
=2D-- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1953,17 +1953,19 @@ static inline unsigned long wait_table_bits(unsigne=
d long size)
  * done. Non-atomic initialization, single-pass.
  */
 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long=
 zone,
=2D		unsigned long start_pfn)
+		unsigned long start_pfn, int early)
 {
 	struct page *page;
 	unsigned long end_pfn =3D start_pfn + size;
 	unsigned long pfn;
=20
 	for (pfn =3D start_pfn; pfn < end_pfn; pfn++) {
=2D		if (!early_pfn_valid(pfn))
=2D			continue;
=2D		if (!early_pfn_in_nid(pfn, nid))
=2D			continue;
+		if (early) {
+			if (!early_pfn_valid(pfn))
+				continue;
+			if (!early_pfn_in_nid(pfn, nid))
+				continue;
+		}
 		page =3D 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,
=20
 #ifndef __HAVE_ARCH_MEMMAP_INIT
 #define memmap_init(size, nid, zone, start_pfn) \
=2D	memmap_init_zone((size), (nid), (zone), (start_pfn))
+	memmap_init_zone((size), (nid), (zone), (start_pfn), 1)
 #endif
=20
 static int __cpuinit zone_batchsize(struct zone *zone)