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

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
#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);
......
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