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authorDave Hansen <dave@linux.vnet.ibm.com>2011-03-22 16:33:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-22 17:44:04 -0700
commit22e057c5923e60debad318cbeaee33033b110bc8 (patch)
tree7dd6d7b5ed93974263377cd458384b85b2847041 /fs/proc/task_mmu.c
parent3c9acc7849b1eab7ffc75e933404c5f32865d9a2 (diff)
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: Dave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: David 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
-rw-r--r--fs/proc/task_mmu.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index d7e2af334076..26f9cc00102c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1,5 +1,6 @@
#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);