Messages in this thread Patch in this message | | | Subject | [PATCH 4/5] teach smaps_pte_range() about THP pmds | From | Dave Hansen <> | Date | Wed, 09 Feb 2011 11:54:11 -0800 |
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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> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> ---
linux-2.6.git-dave/fs/proc/task_mmu.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff -puN fs/proc/task_mmu.c~teach-smaps_pte_range-about-thp-pmds fs/proc/task_mmu.c --- linux-2.6.git/fs/proc/task_mmu.c~teach-smaps_pte_range-about-thp-pmds 2011-02-09 11:41:43.919557155 -0800 +++ linux-2.6.git-dave/fs/proc/task_mmu.c 2011-02-09 11:41:43.927557149 -0800 @@ -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 +387,16 @@ static int smaps_pte_range(pmd_t *pmd, u pte_t *pte; spinlock_t *ptl; - split_huge_page_pmd(walk->mm, pmd); - + 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); + spin_lock(&walk->mm->page_table_lock); + } else { + smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_SIZE, walk); + return 0; + } + } 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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