[v4 08/15] mm: zero struct pages during initialization
From: Pavel Tatashin <hidden>
Date: 2017-08-02 20:39:57
Also in:
linux-arm-kernel, linux-mm, lkml, sparclinux
Subsystem:
memory management, memory management - core, memory management - page allocator, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Linus Torvalds
Add struct page zeroing as a part of initialization of other fields in __init_single_page(). Signed-off-by: Pavel Tatashin <redacted> Reviewed-by: Steven Sistare <redacted> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Bob Picco <redacted> --- include/linux/mm.h | 9 +++++++++ mm/page_alloc.c | 1 + 2 files changed, 10 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 46b9ac5e8569..183ac5e733db 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -94,6 +94,15 @@ extern int mmap_rnd_compat_bits __read_mostly; #endif /* + * On some architectures it is expensive to call memset() for small sizes. + * Those architectures should provide their own implementation of "struct page" + * zeroing by defining this macro in <asm/pgtable.h>. + */ +#ifndef mm_zero_struct_page +#define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) +#endif + +/* * Default maximum number of active map areas, this limits the number of vmas * per mm struct. Users can overwrite this number by sysctl but there is a * problem.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 99b9e2e06319..debea7c0febb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -1168,6 +1168,7 @@ static void free_one_page(struct zone *zone, static void __meminit __init_single_page(struct page *page, unsigned long pfn, unsigned long zone, int nid) { + mm_zero_struct_page(page); set_page_links(page, zone, nid, pfn); init_page_count(page); page_mapcount_reset(page);
--
2.13.3