Re: [PATCH] Fix sparsemem on Cell (take 3)

Dave Hansen
2007-01-07T08:58:34Z

On Fri, 2007-01-05 at 22:52 -0600, John Rose wrote:
> > I dropped this on the floor over Christmas. This has had a few smoke
> > tests on ppc64 and i386 and is ready for -mm. Against 2.6.20-rc2-mm1.
>
> Could this break ia64, given that it uses memmap_init_zone()?

You are right, I think it does.

Here's an updated patch to replace the earlier one. I had to move the
enum definition over to a different header because ia64 evidently has a
different include order.

---

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.

It has been compile tested on ia64, s390, i386 and x86_64.

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

---

lxc-dave/arch/ia64/mm/init.c | 5 +++--
lxc-dave/arch/s390/mm/vmem.c | 3 ++-
lxc-dave/include/linux/mm.h | 3 ++-
lxc-dave/include/linux/mmzone.h | 8 ++++++--
lxc-dave/mm/memory_hotplug.c | 6 ++++--
lxc-dave/mm/page_alloc.c | 25 +++++++++++++++++--------
6 files changed, 34 insertions(+), 16 deletions(-)

diff -puN arch/s390/mm/vmem.c~Re-_PATCH_Fix_sparsemem_on_Cell arch/s390/mm/vmem.c
--- lxc/arch/s390/mm/vmem.c~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-05 15:38:23.000000000 -0800
+++ lxc-dave/arch/s390/mm/vmem.c 2007-01-07 00:47:02.000000000 -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),
+ MEMMAP_EARLY);
}
}

diff -puN include/linux/mm.h~Re-_PATCH_Fix_sparsemem_on_Cell include/linux/mm.h
--- lxc/include/linux/mm.h~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-05 15:38:23.000000000 -0800
+++ lxc-dave/include/linux/mm.h 2007-01-06 23:57:59.000000000 -0800
@@ -979,7 +979,8 @@ 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);
+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 include/linux/mmzone.h~Re-_PATCH_Fix_sparsemem_on_Cell include/linux/mmzone.h
--- lxc/include/linux/mmzone.h~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-05 15:38:23.000000000 -0800
+++ lxc-dave/include/linux/mmzone.h 2007-01-06 23:58:15.000000000 -0800
@@ -471,9 +471,13 @@ void build_all_zonelists(void);
void wakeup_kswapd(struct zone *zone, int order);
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
int classzone_idx, int alloc_flags);
-
+enum memmap_context {
+ MEMMAP_EARLY,
+ MEMMAP_HOTPLUG,
+};
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);
diff -puN mm/memory_hotplug.c~Re-_PATCH_Fix_sparsemem_on_Cell mm/memory_hotplug.c
--- lxc/mm/memory_hotplug.c~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-05 15:38:23.000000000 -0800
+++ lxc-dave/mm/memory_hotplug.c 2007-01-05 15:38:23.000000000 -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 mm/page_alloc.c~Re-_PATCH_Fix_sparsemem_on_Cell mm/page_alloc.c
--- lxc/mm/page_alloc.c~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-05 15:38:23.000000000 -0800
+++ lxc-dave/mm/page_alloc.c 2007-01-07 00:35:27.000000000 -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 arch/ia64/mm/init.c~Re-_PATCH_Fix_sparsemem_on_Cell arch/ia64/mm/init.c
--- lxc/arch/ia64/mm/init.c~Re-_PATCH_Fix_sparsemem_on_Cell 2007-01-06 23:58:55.000000000 -0800
+++ lxc-dave/arch/ia64/mm/init.c 2007-01-07 00:08:01.000000000 -0800
@@ -541,7 +541,8 @@ virtual_memmap_init (u64 start, u64 end,

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),
+ MEMMAP_EARLY);
return 0;
}

@@ -550,7 +551,7 @@ memmap_init (unsigned long size, int nid
unsigned long start_pfn)
{
if (!vmem_map)
- memmap_init_zone(size, nid, zone, start_pfn);
+ memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
else {
struct page *start;
struct memmap_init_callback_data args;
_

-- Dave