The patch titled
Fix boot problem with iSeries lacking hugepage support
has been added to the -mm tree. Its filename is
fix-boot-problem-with-iseries-lacking-hugepage-support.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Fix boot problem with iSeries lacking hugepage support
From: mel@xxxxxxxxx (Mel Gorman)
Ordinarily the size of a pageblock is determined at compile-time based on
the hugepage size. On PPC64, the hugepage size is determined at runtime
based on what is supported by the machine. With legacy machines such as
iSeries that do not support hugepages, HPAGE_SHIFT becomes 0. This results
in pageblock_order being set to -PAGE_SHIFT and a crash results shortly
afterwards.
This patch sets HUGETLB_PAGE_SIZE_VARIABLE for PPC64 and adds a function to
select a sensible value for pageblock order by default. It checks that
HPAGE_SHIFT is a sensible value before using the hugepage size; if it is
not MAX_ORDER-1 is used.
Credit goes to Stephen Rothwell for identifying the bug and testing
candidate patches. Additional credit goes to Andy Whitcroft for spotting a
problem with respects to IA-64 before releasing. Additional credit to
David Gibson for testing with the libhugetlbfs test suite.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Tested-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 5 +++++
mm/page_alloc.c | 14 ++++++++++++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff -puN arch/powerpc/Kconfig~fix-boot-problem-with-iseries-lacking-hugepage-support arch/powerpc/Kconfig
--- a/arch/powerpc/Kconfig~fix-boot-problem-with-iseries-lacking-hugepage-support
+++ a/arch/powerpc/Kconfig
@@ -187,6 +187,11 @@ config FORCE_MAX_ZONEORDER
default "9" if PPC_64K_PAGES
default "13"
+config HUGETLB_PAGE_SIZE_VARIABLE
+ bool
+ depends on HUGETLB_PAGE
+ default y
+
config MATH_EMULATION
bool "Math emulation"
depends on 4xx || 8xx || E200 || PPC_MPC832x || E500
diff -puN mm/page_alloc.c~fix-boot-problem-with-iseries-lacking-hugepage-support mm/page_alloc.c
--- a/mm/page_alloc.c~fix-boot-problem-with-iseries-lacking-hugepage-support
+++ a/mm/page_alloc.c
@@ -3266,6 +3266,16 @@ static void inline setup_usemap(struct p
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
+
+/* Return a sensible default order for the pageblock size. */
+static inline int __init pageblock_default_order(void)
+{
+ if (HPAGE_SHIFT > PAGE_SHIFT)
+ return HUGETLB_PAGE_ORDER;
+
+ return MAX_ORDER-1;
+}
+
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
static inline void __init set_pageblock_order(unsigned int order)
{
@@ -3281,7 +3291,7 @@ static inline void __init set_pageblock_
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
-/* Defined this way to avoid accidently referencing HUGETLB_PAGE_ORDER */
+#define pageblock_default_order(x) (0)
#define set_pageblock_order(x) do {} while (0)
#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
@@ -3366,7 +3376,7 @@ static void __meminit free_area_init_cor
if (!size)
continue;
- set_pageblock_order(HUGETLB_PAGE_ORDER);
+ set_pageblock_order(pageblock_default_order());
setup_usemap(pgdat, zone, size);
ret = init_currently_empty_zone(zone, zone_start_pfn,
size, MEMMAP_EARLY);
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
origin.patch
fix-boot-problem-with-iseries-lacking-hugepage-support.patch
fix-boot-problem-with-iseries-lacking-hugepage-support-fix.patch
mem-policy-fix-mempolicy-usage-in-pci-driver.patch
memory-hotplug-add-removable-to-sysfs-to-show-memblock-removability.patch
page-allocator-clean-up-pcp-draining-functions.patch
page-owner-tracking-leak-detector.patch
add-debugging-aid-for-memory-initialisation-problems.patch
-
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