linux/arch/ia64/mm/hugetlbpage.c

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/*
* IA-64 Huge TLB Page Support for Kernel.
*
* Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
* Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
*
* Sep, 2003: add numa support
* Feb, 2004: dynamic hugetlb page size via boot parameter
*/
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/log2.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT;
pte_t *
huge_pte_alloc (struct mm_struct *mm, unsigned long addr)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, taddr);
pud = pud_alloc(mm, pgd, taddr);
if (pud) {
pmd = pmd_alloc(mm, pud, taddr);
if (pmd)
pte = pte_alloc_map(mm, pmd, taddr);
}
return pte;
}
pte_t *
huge_pte_offset (struct mm_struct *mm, unsigned long addr)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, taddr);
if (pgd_present(*pgd)) {
pud = pud_offset(pgd, taddr);
if (pud_present(*pud)) {
pmd = pmd_offset(pud, taddr);
if (pmd_present(*pmd))
pte = pte_offset_map(pmd, taddr);
}
}
return pte;
}
[PATCH] shared page table for hugetlb page Following up with the work on shared page table done by Dave McCracken. This set of patch target shared page table for hugetlb memory only. The shared page table is particular useful in the situation of large number of independent processes sharing large shared memory segments. In the normal page case, the amount of memory saved from process' page table is quite significant. For hugetlb, the saving on page table memory is not the primary objective (as hugetlb itself already cuts down page table overhead significantly), instead, the purpose of using shared page table on hugetlb is to allow faster TLB refill and smaller cache pollution upon TLB miss. With PT sharing, pte entries are shared among hundreds of processes, the cache consumption used by all the page table is smaller and in return, application gets much higher cache hit ratio. One other effect is that cache hit ratio with hardware page walker hitting on pte in cache will be higher and this helps to reduce tlb miss latency. These two effects contribute to higher application performance. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Dave McCracken <dmccr@us.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Adam Litke <agl@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 04:32:03 +00:00
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
return 0;
}
#define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
/*
[PATCH] hugepage: is_aligned_hugepage_range() cleanup Quite a long time back, prepare_hugepage_range() replaced is_aligned_hugepage_range() as the callback from mm/mmap.c to arch code to verify if an address range is suitable for a hugepage mapping. is_aligned_hugepage_range() stuck around, but only to implement prepare_hugepage_range() on archs which didn't implement their own. Most archs (everything except ia64 and powerpc) used the same implementation of is_aligned_hugepage_range(). On powerpc, which implements its own prepare_hugepage_range(), the custom version was never used. In addition, "is_aligned_hugepage_range()" was a bad name, because it suggests it returns true iff the given range is a good hugepage range, whereas in fact it returns 0-or-error (so the sense is reversed). This patch cleans up by abolishing is_aligned_hugepage_range(). Instead prepare_hugepage_range() is defined directly. Most archs use the default version, which simply checks the given region is aligned to the size of a hugepage. ia64 and powerpc define custom versions. The ia64 one simply checks that the range is in the correct address space region in addition to being suitably aligned. The powerpc version (just as previously) checks for suitable addresses, and if necessary performs low-level MMU frobbing to set up new areas for use by hugepages. No libhugetlbfs testsuite regressions on ppc64 (POWER5 LPAR). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 08:09:01 +00:00
* Don't actually need to do any preparation, but need to make sure
* the address is in the right region.
*/
int prepare_hugepage_range(unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
if (REGION_NUMBER(addr) != RGN_HPAGE)
return -EINVAL;
return 0;
}
struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
{
struct page *page;
pte_t *ptep;
if (REGION_NUMBER(addr) != RGN_HPAGE)
return ERR_PTR(-EINVAL);
ptep = huge_pte_offset(mm, addr);
if (!ptep || pte_none(*ptep))
return NULL;
page = pte_page(*ptep);
page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
return page;
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
{
return NULL;
}
void hugetlb_free_pgd_range(struct mmu_gather **tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
/*
* This is called to free hugetlb page tables.
*
* The offset of these addresses from the base of the hugetlb
* region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
* the standard free_pgd_range will free the right page tables.
*
* If floor and ceiling are also in the hugetlb region, they
* must likewise be scaled down; but if outside, left unchanged.
*/
addr = htlbpage_to_page(addr);
end = htlbpage_to_page(end);
if (REGION_NUMBER(floor) == RGN_HPAGE)
floor = htlbpage_to_page(floor);
if (REGION_NUMBER(ceiling) == RGN_HPAGE)
ceiling = htlbpage_to_page(ceiling);
free_pgd_range(tlb, addr, end, floor, ceiling);
}
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct vm_area_struct *vmm;
if (len > RGN_MAP_LIMIT)
return -ENOMEM;
if (len & ~HPAGE_MASK)
return -EINVAL;
/* Handle MAP_FIXED */
if (flags & MAP_FIXED) {
if (prepare_hugepage_range(addr, len))
return -EINVAL;
return addr;
}
/* This code assumes that RGN_HPAGE != 0. */
if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
addr = HPAGE_REGION_BASE;
else
addr = ALIGN(addr, HPAGE_SIZE);
for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
/* At this point: (!vmm || addr < vmm->vm_end). */
if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
return -ENOMEM;
if (!vmm || (addr + len) <= vmm->vm_start)
return addr;
addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
}
}
static int __init hugetlb_setup_sz(char *str)
{
u64 tr_pages;
unsigned long long size;
if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
/*
* shouldn't happen, but just in case.
*/
tr_pages = 0x15557000UL;
size = memparse(str, &str);
if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
size <= PAGE_SIZE ||
size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
printk(KERN_WARNING "Invalid huge page size specified\n");
return 1;
}
hpage_shift = __ffs(size);
/*
* boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
* override here with new page shift.
*/
ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
Do not depend on MAX_ORDER when grouping pages by mobility Currently mobility grouping works at the MAX_ORDER_NR_PAGES level. This makes sense for the majority of users where this is also the huge page size. However, on platforms like ia64 where the huge page size is runtime configurable it is desirable to group at a lower order. On x86_64 and occasionally on x86, the hugepage size may not always be MAX_ORDER_NR_PAGES. This patch groups pages together based on the value of HUGETLB_PAGE_ORDER. It uses a compile-time constant if possible and a variable where the huge page size is runtime configurable. It is assumed that grouping should be done at the lowest sensible order and that the user would not want to override this. If this is not true, page_block order could be forced to a variable initialised via a boot-time kernel parameter. One potential issue with this patch is that IA64 now parses hugepagesz with early_param() instead of __setup(). __setup() is called after the memory allocator has been initialised and the pageblock bitmaps already setup. In tests on one IA64 there did not seem to be any problem with using early_param() and in fact may be more correct as it guarantees the parameter is handled before the parsing of hugepages=. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 08:26:01 +00:00
return 0;
}
Do not depend on MAX_ORDER when grouping pages by mobility Currently mobility grouping works at the MAX_ORDER_NR_PAGES level. This makes sense for the majority of users where this is also the huge page size. However, on platforms like ia64 where the huge page size is runtime configurable it is desirable to group at a lower order. On x86_64 and occasionally on x86, the hugepage size may not always be MAX_ORDER_NR_PAGES. This patch groups pages together based on the value of HUGETLB_PAGE_ORDER. It uses a compile-time constant if possible and a variable where the huge page size is runtime configurable. It is assumed that grouping should be done at the lowest sensible order and that the user would not want to override this. If this is not true, page_block order could be forced to a variable initialised via a boot-time kernel parameter. One potential issue with this patch is that IA64 now parses hugepagesz with early_param() instead of __setup(). __setup() is called after the memory allocator has been initialised and the pageblock bitmaps already setup. In tests on one IA64 there did not seem to be any problem with using early_param() and in fact may be more correct as it guarantees the parameter is handled before the parsing of hugepages=. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 08:26:01 +00:00
early_param("hugepagesz", hugetlb_setup_sz);