Re: [PATCH] Fix boot problem with iSeries lacking hugepage support
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2007-11-15 10:33:20
Also in:
linux-mm, lkml
On Thu, 15 Nov 2007 10:13:22 +0000 mel@skynet.ie (Mel Gorman) wrote:
This patch is a fix for 2.6.24. 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.
umm.
+ +/* Return a sensible default order for the pageblock size. */ +static inline int __init pageblock_default_order(void)
inline and __init doesn't make sense.
quoted hunk ↗ jump to hunk
+{ + 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) {@@ -3357,7 +3367,7 @@ 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)
that won't compile.
quoted hunk ↗ jump to hunk
#define set_pageblock_order(x) do {} while (0) #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */@@ -3442,7 +3452,7 @@ 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,
--- a/mm/page_alloc.c~fix-boot-problem-with-iseries-lacking-hugepage-support-fix
+++ a/mm/page_alloc.c@@ -3268,7 +3268,7 @@ static void inline setup_usemap(struct p #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE /* Return a sensible default order for the pageblock size. */ -static inline int __init pageblock_default_order(void) +static inline int pageblock_default_order(void) { if (HPAGE_SHIFT > PAGE_SHIFT) return HUGETLB_PAGE_ORDER;
@@ -3291,7 +3291,11 @@ static inline void __init set_pageblock_ } #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ -#define pageblock_default_order(x) (0) +static inline int pageblock_default_order(void) +{ + return 0; +} + #define set_pageblock_order(x) do {} while (0) #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
_ please avoid adding macros when C could have been used. C is nicer to look at and has typechecking and stuff.