Re: [PATCH] Fix sparsemem on Cell

Dave Hansen
2006-12-19T19:35:45Z

Pulling cbe... list off the cc because it is giving annoying 'too many
recipients' warnings.

On Tue, 2006-12-19 at 09:59 +0100, Arnd Bergmann wrote:
> On Tuesday 19 December 2006 00:16, Dave Hansen wrote:
> > How about an enum, or a pair of #defines?
> >
> > enum context
> > {
> > EARLY,
> > HOTPLUG
> > };

This patch should do the trick. Arnd, can you try this to make sure it
solves the issue? Also, if you get a chance, could you do a quick s390
boot of it? It was the only arch touched by this whole thing.

It compiles on all of my i386 .configs.

--

The following patch fixes an oops experienced on the Cell architecture
when init-time functions, early_*(), are called at runtime. It alters
the call paths to make sure that the callers explicitly say whether the
call is being made on behalf of a hotplug even, or happening at
boot-time.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>

---

lxc-dave/arch/s390/mm/vmem.c | 3 ++-
lxc-dave/include/linux/mm.h | 7 ++++++-
lxc-dave/include/linux/mmzone.h | 3 ++-
lxc-dave/mm/memory_hotplug.c | 6 ++++--
lxc-dave/mm/page_alloc.c | 25 +++++++++++++++++--------
5 files changed, 31 insertions(+), 13 deletions(-)

diff -puN mm/page_alloc.c~sparsemem-enum1 mm/page_alloc.c
--- lxc/mm/page_alloc.c~sparsemem-enum1 2006-12-19 09:38:34.000000000 -0800
+++ lxc-dave/mm/page_alloc.c 2006-12-19 11:18:24.000000000 -0800
@@ -2062,17 +2062,24 @@ static inline unsigned long wait_table_b
* 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, enum memmap_context context)
{
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;
+ /*
+ * There can be holes in boot-time mem_map[]s
+ * handed to this function. They do not
+ * exist on hotplugged memory.
+ */
+ if (context == MEMMAP_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);
@@ -2102,7 +2109,7 @@ void zone_init_free_lists(struct pglist_

#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), MEMMAP_EARLY)
#endif

static int __cpuinit zone_batchsize(struct zone *zone)
@@ -2348,7 +2355,8 @@ static __meminit void zone_pcp_init(stru

__meminit int init_currently_empty_zone(struct zone *zone,
unsigned long zone_start_pfn,
- unsigned long size)
+ unsigned long size,
+ enum memmap_context context)
{
struct pglist_data *pgdat = zone->zone_pgdat;
int ret;
@@ -2792,7 +2800,8 @@ static void __meminit free_area_init_cor
if (!size)
continue;

- ret = init_currently_empty_zone(zone, zone_start_pfn, size);
+ ret = init_currently_empty_zone(zone, zone_start_pfn,
+ size, MEMMAP_EARLY);
BUG_ON(ret);
zone_start_pfn += size;
}
diff -puN include/linux/mm.h~sparsemem-enum1 include/linux/mm.h
--- lxc/include/linux/mm.h~sparsemem-enum1 2006-12-19 09:38:45.000000000 -0800
+++ lxc-dave/include/linux/mm.h 2006-12-19 09:50:47.000000000 -0800
@@ -979,7 +979,12 @@ extern int early_pfn_to_nid(unsigned lon
#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);
+enum memmap_context {
+ MEMMAP_EARLY,
+ MEMMAP_HOTPLUG,
+};
+extern void memmap_init_zone(unsigned long, int, unsigned long,
+ unsigned long, enum memmap_context);
extern void setup_per_zone_pages_min(void);
extern void mem_init(void);
extern void show_mem(void);
diff -puN mm/memory_hotplug.c~sparsemem-enum1 mm/memory_hotplug.c
--- lxc/mm/memory_hotplug.c~sparsemem-enum1 2006-12-19 09:39:19.000000000 -0800
+++ lxc-dave/mm/memory_hotplug.c 2006-12-19 09:50:24.000000000 -0800
@@ -67,11 +67,13 @@ static int __add_zone(struct zone *zone,
zone_type = zone - pgdat->node_zones;
if (!populated_zone(zone)) {
int ret = 0;
- ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
+ ret = init_currently_empty_zone(zone, phys_start_pfn,
+ nr_pages, MEMMAP_HOTPLUG);
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, MEMMAP_HOTPLUG);
return 0;
}

diff -puN arch/s390/mm/vmem.c~sparsemem-enum1 arch/s390/mm/vmem.c
--- lxc/arch/s390/mm/vmem.c~sparsemem-enum1 2006-12-19 09:42:26.000000000 -0800
+++ lxc-dave/arch/s390/mm/vmem.c 2006-12-19 11:17:49.000000000 -0800
@@ -61,7 +61,8 @@ void memmap_init(unsigned long size, int

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),
+ context);
}
}

diff -puN include/linux/mmzone.h~sparsemem-enum1 include/linux/mmzone.h
--- lxc/include/linux/mmzone.h~sparsemem-enum1 2006-12-19 09:48:58.000000000 -0800
+++ lxc-dave/include/linux/mmzone.h 2006-12-19 09:53:42.000000000 -0800
@@ -474,7 +474,8 @@ int zone_watermark_ok(struct zone *z, in
int classzone_idx, int alloc_flags);

extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
- unsigned long size);
+ unsigned long size,
+ enum memmap_context context);

#ifdef CONFIG_HAVE_MEMORY_PRESENT
void memory_present(int nid, unsigned long start, unsigned long end);
_

-- Dave