revert "s390/mm: make hugepages_supported a boot time decision" (41318bfe) · Commits · 戴 / test

Heiko noticed that the current check for hugepage support on s390 is a little bit too harsh as systems which do not support will crash. The reason is that pageblock_order can now get negative when we set HPAGE_SHIFT to 0. To avoid all this and to avoid opening another can of worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best to simply allow architectures to define their own hugepages_supported(). Revert ("s390/mm: make hugepages_supported a boot time decision") in preparation. Signed-off-by:

Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by:

Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/include/asm/page.h

+4 −4

Original line number	Diff line number	Diff line
		@@ -17,10 +17,7 @@
		#define PAGE_DEFAULT_ACC 0
		#define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4)

		#include <asm/setup.h>
		#ifndef __ASSEMBLY__

		extern unsigned int HPAGE_SHIFT;
		#define HPAGE_SHIFT 20
		#define HPAGE_SIZE (1UL << HPAGE_SHIFT)
		#define HPAGE_MASK (~(HPAGE_SIZE - 1))
		#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
		@@ -30,6 +27,9 @@ extern unsigned int HPAGE_SHIFT;
		#define ARCH_HAS_PREPARE_HUGEPAGE
		#define ARCH_HAS_HUGEPAGE_CLEAR_FLUSH

		#include <asm/setup.h>
		#ifndef __ASSEMBLY__

		static inline void storage_key_init_range(unsigned long start, unsigned long end)
		{
		#if PAGE_DEFAULT_KEY

arch/s390/kernel/setup.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -885,8 +885,6 @@ void __init setup_arch(char **cmdline_p)
		*/
		setup_hwcaps();

		HPAGE_SHIFT = MACHINE_HAS_HPAGE ? 20 : 0;

		/*
		* Create kernel page tables and switch to virtual addressing.
		*/

arch/s390/mm/pgtable.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -31,8 +31,6 @@
		#define ALLOC_ORDER 2
		#define FRAG_MASK 0x03

		unsigned int HPAGE_SHIFT;

		unsigned long crst_table_alloc(struct mm_struct mm)
		{
		struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);

Admin message