On 03/31/2011 05:27 PM, Kevin Cernekee wrote:
From: Michael Sundius<msundius@xxxxxxxxx>
Fix 3 problems in the MIPS SPARSEMEM implementation:
1) mem_init() sets/clears PG_reserved on all pages in the HIGHMEM range
without checking to see whether the page descriptor actually exists.
2) bootmem_init() never calls memory_present() on HIGHMEM pages, so
page descriptors are never created for them if SPARSEMEM is enabled.
3) bootmem_init() calls memory_present() on lowmem pages before bootmem
is fully set up. This is bad because memory_present() can allocate
bootmem in some circumstances (e.g. if SPARSEMEM_EXTREME ever got
enabled).
I think this may do the same thing as my patch:
http://patchwork.linux-mips.org/patch/1988/
Although my patch had different motivations, and changes some other
things around too.
David Daney
Signed-off-by: Michael Sundius<msundius@xxxxxxxxx>
Signed-off-by: Kevin Cernekee<cernekee@xxxxxxxxx>
Cc: stable@xxxxxxxxxx
---
arch/mips/kernel/setup.c | 18 +++++++++++++++++-
arch/mips/mm/init.c | 3 +++
2 files changed, 20 insertions(+), 1 deletions(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 8ad1d56..1f9f902 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -390,7 +390,6 @@ static void __init bootmem_init(void)
/* Register lowmem ranges */
free_bootmem(PFN_PHYS(start), size<< PAGE_SHIFT);
- memory_present(0, start, end);
}
/*
@@ -402,6 +401,23 @@ static void __init bootmem_init(void)
* Reserve initrd memory if needed.
*/
finalize_initrd();
+
+ /*
+ * Call memory_present() on all valid ranges, for SPARSEMEM.
+ * This must be done after setting up bootmem, since memory_present()
+ * may allocate bootmem.
+ */
+ for (i = 0; i< boot_mem_map.nr_map; i++) {
+ unsigned long start, end;
+
+ if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
+ continue;
+
+ start = PFN_UP(boot_mem_map.map[i].addr);
+ end = PFN_DOWN(boot_mem_map.map[i].addr
+ + boot_mem_map.map[i].size);
+ memory_present(0, start, end);
+ }
}
#endif /* CONFIG_SGI_IP27 */
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 279599e..78a4cf2 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -392,6 +392,9 @@ void __init mem_init(void)
for (tmp = highstart_pfn; tmp< highend_pfn; tmp++) {
struct page *page = pfn_to_page(tmp);
+ if (!pfn_valid(tmp))
+ continue;
+
if (!page_is_ram(tmp)) {
SetPageReserved(page);
continue;
