![Naoya Horiguchi](/assets/img/avatar_default.png)
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>
182 lines
4 KiB
C
182 lines
4 KiB
C
/*
|
|
* IA-32 Huge TLB Page Support for Kernel.
|
|
*
|
|
* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/err.h>
|
|
#include <linux/sysctl.h>
|
|
#include <asm/mman.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgalloc.h>
|
|
|
|
#if 0 /* This is just for testing */
|
|
struct page *
|
|
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
|
|
{
|
|
unsigned long start = address;
|
|
int length = 1;
|
|
int nr;
|
|
struct page *page;
|
|
struct vm_area_struct *vma;
|
|
|
|
vma = find_vma(mm, addr);
|
|
if (!vma || !is_vm_hugetlb_page(vma))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
pte = huge_pte_offset(mm, address);
|
|
|
|
/* hugetlb should be locked, and hence, prefaulted */
|
|
WARN_ON(!pte || pte_none(*pte));
|
|
|
|
page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
|
|
|
|
WARN_ON(!PageHead(page));
|
|
|
|
return page;
|
|
}
|
|
|
|
int pmd_huge(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int pud_huge(pud_t pud)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
struct page *
|
|
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int write)
|
|
{
|
|
return NULL;
|
|
}
|
|
#else
|
|
|
|
struct page *
|
|
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
|
|
{
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
int pmd_huge(pmd_t pmd)
|
|
{
|
|
return !!(pmd_val(pmd) & _PAGE_PSE);
|
|
}
|
|
|
|
int pud_huge(pud_t pud)
|
|
{
|
|
return !!(pud_val(pud) & _PAGE_PSE);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
|
|
unsigned long addr, unsigned long len,
|
|
unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct hstate *h = hstate_file(file);
|
|
struct vm_unmapped_area_info info;
|
|
|
|
info.flags = 0;
|
|
info.length = len;
|
|
info.low_limit = current->mm->mmap_legacy_base;
|
|
info.high_limit = TASK_SIZE;
|
|
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
|
|
info.align_offset = 0;
|
|
return vm_unmapped_area(&info);
|
|
}
|
|
|
|
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
|
|
unsigned long addr0, unsigned long len,
|
|
unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct hstate *h = hstate_file(file);
|
|
struct vm_unmapped_area_info info;
|
|
unsigned long addr;
|
|
|
|
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
|
|
info.length = len;
|
|
info.low_limit = PAGE_SIZE;
|
|
info.high_limit = current->mm->mmap_base;
|
|
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
|
|
info.align_offset = 0;
|
|
addr = vm_unmapped_area(&info);
|
|
|
|
/*
|
|
* A failed mmap() very likely causes application failure,
|
|
* so fall back to the bottom-up function here. This scenario
|
|
* can happen with large stack limits and large mmap()
|
|
* allocations.
|
|
*/
|
|
if (addr & ~PAGE_MASK) {
|
|
VM_BUG_ON(addr != -ENOMEM);
|
|
info.flags = 0;
|
|
info.low_limit = TASK_UNMAPPED_BASE;
|
|
info.high_limit = TASK_SIZE;
|
|
addr = vm_unmapped_area(&info);
|
|
}
|
|
|
|
return addr;
|
|
}
|
|
|
|
unsigned long
|
|
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
|
unsigned long len, unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct hstate *h = hstate_file(file);
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
|
|
if (len & ~huge_page_mask(h))
|
|
return -EINVAL;
|
|
if (len > TASK_SIZE)
|
|
return -ENOMEM;
|
|
|
|
if (flags & MAP_FIXED) {
|
|
if (prepare_hugepage_range(file, addr, len))
|
|
return -EINVAL;
|
|
return addr;
|
|
}
|
|
|
|
if (addr) {
|
|
addr = ALIGN(addr, huge_page_size(h));
|
|
vma = find_vma(mm, addr);
|
|
if (TASK_SIZE - len >= addr &&
|
|
(!vma || addr + len <= vma->vm_start))
|
|
return addr;
|
|
}
|
|
if (mm->get_unmapped_area == arch_get_unmapped_area)
|
|
return hugetlb_get_unmapped_area_bottomup(file, addr, len,
|
|
pgoff, flags);
|
|
else
|
|
return hugetlb_get_unmapped_area_topdown(file, addr, len,
|
|
pgoff, flags);
|
|
}
|
|
#endif /* CONFIG_HUGETLB_PAGE */
|
|
|
|
#ifdef CONFIG_X86_64
|
|
static __init int setup_hugepagesz(char *opt)
|
|
{
|
|
unsigned long ps = memparse(opt, &opt);
|
|
if (ps == PMD_SIZE) {
|
|
hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
|
|
} else if (ps == PUD_SIZE && cpu_has_gbpages) {
|
|
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
|
|
} else {
|
|
printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n",
|
|
ps >> 20);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
__setup("hugepagesz=", setup_hugepagesz);
|
|
#endif
|