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authorHans Rosenfeld <hans.rosenfeld@amd.com>2008-03-21 19:46:59 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-03-22 20:03:10 -0400
commitf16278c679aa72e28288435b313ba2d4494d6be5 (patch)
tree00bf8421f056748a5725f2aa165614f69672cc4e /fs/proc
parent51ec92e295d563dd5712d198a7e46c2ae5ccccb2 (diff)
Change pagemap output format to allow for future reporting of huge pages
Change pagemap output format to allow for future reporting of huge pages. (Format comment and minor cleanups: mpm@selenic.com) Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/task_mmu.c50
1 files changed, 34 insertions, 16 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 4206454734e0..9dfb5ff24209 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -527,13 +527,21 @@ struct pagemapread {
527 char __user *out, *end; 527 char __user *out, *end;
528}; 528};
529 529
530#define PM_ENTRY_BYTES sizeof(u64) 530#define PM_ENTRY_BYTES sizeof(u64)
531#define PM_RESERVED_BITS 3 531#define PM_STATUS_BITS 3
532#define PM_RESERVED_OFFSET (64 - PM_RESERVED_BITS) 532#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
533#define PM_RESERVED_MASK (((1LL<<PM_RESERVED_BITS)-1) << PM_RESERVED_OFFSET) 533#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
534#define PM_SPECIAL(nr) (((nr) << PM_RESERVED_OFFSET) & PM_RESERVED_MASK) 534#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
535#define PM_NOT_PRESENT PM_SPECIAL(1LL) 535#define PM_PSHIFT_BITS 6
536#define PM_SWAP PM_SPECIAL(2LL) 536#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
537#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
538#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
539#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
540#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
541
542#define PM_PRESENT PM_STATUS(4LL)
543#define PM_SWAP PM_STATUS(2LL)
544#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT)
537#define PM_END_OF_BUFFER 1 545#define PM_END_OF_BUFFER 1
538 546
539static int add_to_pagemap(unsigned long addr, u64 pfn, 547static int add_to_pagemap(unsigned long addr, u64 pfn,
@@ -574,7 +582,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
574u64 swap_pte_to_pagemap_entry(pte_t pte) 582u64 swap_pte_to_pagemap_entry(pte_t pte)
575{ 583{
576 swp_entry_t e = pte_to_swp_entry(pte); 584 swp_entry_t e = pte_to_swp_entry(pte);
577 return PM_SWAP | swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); 585 return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
578} 586}
579 587
580static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 588static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
@@ -588,9 +596,11 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
588 u64 pfn = PM_NOT_PRESENT; 596 u64 pfn = PM_NOT_PRESENT;
589 pte = pte_offset_map(pmd, addr); 597 pte = pte_offset_map(pmd, addr);
590 if (is_swap_pte(*pte)) 598 if (is_swap_pte(*pte))
591 pfn = swap_pte_to_pagemap_entry(*pte); 599 pfn = PM_PFRAME(swap_pte_to_pagemap_entry(*pte))
600 | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
592 else if (pte_present(*pte)) 601 else if (pte_present(*pte))
593 pfn = pte_pfn(*pte); 602 pfn = PM_PFRAME(pte_pfn(*pte))
603 | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
594 /* unmap so we're not in atomic when we copy to userspace */ 604 /* unmap so we're not in atomic when we copy to userspace */
595 pte_unmap(pte); 605 pte_unmap(pte);
596 err = add_to_pagemap(addr, pfn, pm); 606 err = add_to_pagemap(addr, pfn, pm);
@@ -611,12 +621,20 @@ static struct mm_walk pagemap_walk = {
611/* 621/*
612 * /proc/pid/pagemap - an array mapping virtual pages to pfns 622 * /proc/pid/pagemap - an array mapping virtual pages to pfns
613 * 623 *
614 * For each page in the address space, this file contains one 64-bit 624 * For each page in the address space, this file contains one 64-bit entry
615 * entry representing the corresponding physical page frame number 625 * consisting of the following:
616 * (PFN) if the page is present. If there is a swap entry for the 626 *
617 * physical page, then an encoding of the swap file number and the 627 * Bits 0-55 page frame number (PFN) if present
618 * page's offset into the swap file are returned. If no page is 628 * Bits 0-4 swap type if swapped
619 * present at all, PM_NOT_PRESENT is returned. This allows determining 629 * Bits 5-55 swap offset if swapped
630 * Bits 55-60 page shift (page size = 1<<page shift)
631 * Bit 61 reserved for future use
632 * Bit 62 page swapped
633 * Bit 63 page present
634 *
635 * If the page is not present but in swap, then the PFN contains an
636 * encoding of the swap file number and the page's offset into the
637 * swap. Unmapped pages return a null PFN. This allows determining
620 * precisely which pages are mapped (or in swap) and comparing mapped 638 * precisely which pages are mapped (or in swap) and comparing mapped
621 * pages between processes. 639 * pages between processes.
622 * 640 *