The patch titled Subject: mm: setup pageblock_order before it's used by sparsemem has been removed from the -mm tree. Its filename was mm-setup-pageblock_order-before-its-used-by-sparsemem.patch
This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Xishi Qiu <qiuxi...@huawei.com> Subject: mm: setup pageblock_order before it's used by sparsemem On architectures with CONFIG_HUGETLB_PAGE_SIZE_VARIABLE set, such as Itanium, pageblock_order is a variable with default value of 0. It's set to the right value by set_pageblock_order() in function free_area_init_core(). But pageblock_order may be used by sparse_init() before free_area_init_core() is called along path: sparse_init() ->sparse_early_usemaps_alloc_node() ->usemap_size() ->SECTION_BLOCKFLAGS_BITS ->((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) The uninitialized pageblock_size will cause memory wasting because usemap_size() returns a much bigger value then it's really needed. For example, on an Itanium platform, sparse_init() pageblock_order=0 usemap_size=24576 free_area_init_core() before pageblock_order=0, usemap_size=24576 free_area_init_core() after pageblock_order=12, usemap_size=8 That means 24K memory has been wasted for each section, so fix it by calling set_pageblock_order() from sparse_init(). Signed-off-by: Xishi Qiu <qiuxi...@huawei.com> Signed-off-by: Jiang Liu <liu...@gmail.com> Cc: Tony Luck <tony.l...@intel.com> Cc: Yinghai Lu <ying...@kernel.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hir...@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com> Cc: David Rientjes <rient...@google.com> Cc: Keping Chen <chenkep...@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> --- mm/internal.h | 2 ++ mm/page_alloc.c | 4 ++-- mm/sparse.c | 3 +++ 3 files changed, 7 insertions(+), 2 deletions(-) diff -puN mm/internal.h~mm-setup-pageblock_order-before-its-used-by-sparsemem mm/internal.h --- a/mm/internal.h~mm-setup-pageblock_order-before-its-used-by-sparsemem +++ a/mm/internal.h @@ -353,3 +353,5 @@ extern u32 hwpoison_filter_enable; extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); + +extern void set_pageblock_order(void); diff -puN mm/page_alloc.c~mm-setup-pageblock_order-before-its-used-by-sparsemem mm/page_alloc.c --- a/mm/page_alloc.c~mm-setup-pageblock_order-before-its-used-by-sparsemem +++ a/mm/page_alloc.c @@ -4304,7 +4304,7 @@ static inline void setup_usemap(struct p #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ -static inline void __init set_pageblock_order(void) +void __init set_pageblock_order(void) { unsigned int order; @@ -4332,7 +4332,7 @@ static inline void __init set_pageblock_ * include/linux/pageblock-flags.h for the values of pageblock_order based on * the kernel config */ -static inline void set_pageblock_order(void) +void __init set_pageblock_order(void) { } diff -puN mm/sparse.c~mm-setup-pageblock_order-before-its-used-by-sparsemem mm/sparse.c --- a/mm/sparse.c~mm-setup-pageblock_order-before-its-used-by-sparsemem +++ a/mm/sparse.c @@ -493,6 +493,9 @@ void __init sparse_init(void) struct page **map_map; #endif + /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */ + set_pageblock_order(); + /* * map is using big page (aka 2M in x86 64 bit) * usemap is less one page (aka 24 bytes) _ Patches currently in -mm which might be from qiuxi...@huawei.com are origin.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html