Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 22e057c5 authored by Dave Hansen's avatar Dave Hansen Committed by Linus Torvalds
Browse files

smaps: teach smaps_pte_range() about THP pmds 



This adds code to explicitly detect and handle pmd_trans_huge() pmds.  It
then passes HPAGE_SIZE units in to the smap_pte_entry() function instead
of PAGE_SIZE.

This means that using /proc/$pid/smaps now will no longer cause THPs to be
broken down in to small pages.

Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: default avatarEric B Munson <emunson@mgebm.net>
Tested-by: default avatarEric B Munson <emunson@mgebm.net>
Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3c9acc78

fs/proc/task_mmu.c

+21 −2
Original line number Diff line number Diff line 
#include <linux/mm.h>

#include <linux/hugetlb.h>

#include <linux/huge_mm.h>

#include <linux/mount.h>

#include <linux/seq_file.h>

#include <linux/highmem.h>
@@ -7,6 +8,7 @@ 
#include <linux/slab.h>

#include <linux/pagemap.h>

#include <linux/mempolicy.h>

#include <linux/rmap.h>

#include <linux/swap.h>

#include <linux/swapops.h>
@@ -385,8 +387,25 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 
	pte_t *pte;

	spinlock_t *ptl;



	split_huge_page_pmd(walk->mm, pmd);



	spin_lock(&walk->mm->page_table_lock);

	if (pmd_trans_huge(*pmd)) {

		if (pmd_trans_splitting(*pmd)) {

			spin_unlock(&walk->mm->page_table_lock);

			wait_split_huge_page(vma->anon_vma, pmd);

		} else {

			smaps_pte_entry(*(pte_t *)pmd, addr,

					HPAGE_PMD_SIZE, walk);

			spin_unlock(&walk->mm->page_table_lock);

			return 0;

		}

	} else {

		spin_unlock(&walk->mm->page_table_lock);

	}

	/*

	 * The mmap_sem held all the way back in m_start() is what

	 * keeps khugepaged out of here and from collapsing things

	 * in here.

	 */

	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);

	for (; addr != end; pte++, addr += PAGE_SIZE)

		smaps_pte_entry(*pte, addr, PAGE_SIZE, walk);