 c177c81e09
			
		
	
	
	c177c81e09
	
	
	
		
			
			Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			74 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			74 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * arch/arm64/mm/hugetlbpage.c
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|  *
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|  * Copyright (C) 2013 Linaro Ltd.
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|  *
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|  * Based on arch/x86/mm/hugetlbpage.c.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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|  */
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| 
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| #include <linux/init.h>
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| #include <linux/fs.h>
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| #include <linux/mm.h>
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| #include <linux/hugetlb.h>
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| #include <linux/pagemap.h>
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| #include <linux/err.h>
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| #include <linux/sysctl.h>
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| #include <asm/mman.h>
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| #include <asm/tlb.h>
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| #include <asm/tlbflush.h>
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| #include <asm/pgalloc.h>
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| 
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| #ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
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| int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
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| {
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| 	return 0;
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| }
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| #endif
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| 
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| struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
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| 			      int write)
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| {
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| 	return ERR_PTR(-EINVAL);
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| }
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| 
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| int pmd_huge(pmd_t pmd)
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| {
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| 	return !(pmd_val(pmd) & PMD_TABLE_BIT);
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| }
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| 
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| int pud_huge(pud_t pud)
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| {
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| #ifndef __PAGETABLE_PMD_FOLDED
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| 	return !(pud_val(pud) & PUD_TABLE_BIT);
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| #else
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| 	return 0;
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| #endif
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| }
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| 
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| static __init int setup_hugepagesz(char *opt)
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| {
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| 	unsigned long ps = memparse(opt, &opt);
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| 	if (ps == PMD_SIZE) {
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| 		hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
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| 	} else if (ps == PUD_SIZE) {
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| 		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
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| 	} else {
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| 		pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
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| 		return 0;
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| 	}
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| 	return 1;
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| }
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| __setup("hugepagesz=", setup_hugepagesz);
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