From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Thu, 22 May 2014 00:42:40 +0000 (+1000)
Subject: smaps: redefine callback functions for page table walker
X-Git-Tag: next-20140530~2^2~397
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=75a5ee54ebb25896b0e388e6ecc93a0f621216fc;p=karo-tx-linux.git

smaps: redefine callback functions for page table walker

smaps_pte_range() connected to pmd_entry() does both of pmd loop and pte
loop.  So this patch moves pte part into smaps_pte() on pte_entry() as
expected by the name.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 442177b1119a..45aaf7616172 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -424,7 +424,6 @@ const struct file_operations proc_tid_maps_operations = {
 
 #ifdef CONFIG_PROC_PAGE_MONITOR
 struct mem_size_stats {
-	struct vm_area_struct *vma;
 	unsigned long resident;
 	unsigned long shared_clean;
 	unsigned long shared_dirty;
@@ -438,15 +437,16 @@ struct mem_size_stats {
 	u64 pss;
 };
 
-
-static void smaps_pte_entry(pte_t ptent, unsigned long addr,
-		unsigned long ptent_size, struct mm_walk *walk)
+static int smaps_pte(pte_t *pte, unsigned long addr, unsigned long end,
+			struct mm_walk *walk)
 {
 	struct mem_size_stats *mss = walk->private;
-	struct vm_area_struct *vma = mss->vma;
+	struct vm_area_struct *vma = walk->vma;
 	pgoff_t pgoff = linear_page_index(vma, addr);
 	struct page *page = NULL;
 	int mapcount;
+	pte_t ptent = *pte;
+	unsigned long ptent_size = end - addr;
 
 	if (pte_present(ptent)) {
 		page = vm_normal_page(vma, addr, ptent);
@@ -463,7 +463,7 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr,
 	}
 
 	if (!page)
-		return;
+		return 0;
 
 	if (PageAnon(page))
 		mss->anonymous += ptent_size;
@@ -489,35 +489,22 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr,
 			mss->private_clean += ptent_size;
 		mss->pss += (ptent_size << PSS_SHIFT);
 	}
+	return 0;
 }
 
-static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-			   struct mm_walk *walk)
+static int smaps_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
+			struct mm_walk *walk)
 {
 	struct mem_size_stats *mss = walk->private;
-	struct vm_area_struct *vma = mss->vma;
-	pte_t *pte;
 	spinlock_t *ptl;
 
-	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
-		smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_PMD_SIZE, walk);
+	if (pmd_trans_huge_lock(pmd, walk->vma, &ptl) == 1) {
+		smaps_pte((pte_t *)pmd, addr, addr + HPAGE_PMD_SIZE, walk);
 		spin_unlock(ptl);
 		mss->anonymous_thp += HPAGE_PMD_SIZE;
-		return 0;
+		/* don't call smaps_pte() */
+		walk->skip = 1;
 	}
-
-	if (pmd_trans_unstable(pmd))
-		return 0;
-	/*
-	 * 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);
-	pte_unmap_unlock(pte - 1, ptl);
-	cond_resched();
 	return 0;
 }
 
@@ -582,16 +569,16 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 	struct vm_area_struct *vma = v;
 	struct mem_size_stats mss;
 	struct mm_walk smaps_walk = {
-		.pmd_entry = smaps_pte_range,
+		.pmd_entry = smaps_pmd,
+		.pte_entry = smaps_pte,
 		.mm = vma->vm_mm,
+		.vma = vma,
 		.private = &mss,
 	};
 
 	memset(&mss, 0, sizeof mss);
-	mss.vma = vma;
 	/* mmap_sem is held in m_start */
-	if (vma->vm_mm && !is_vm_hugetlb_page(vma))
-		walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
+	walk_page_vma(vma, &smaps_walk);
 
 	show_map_vma(m, vma, is_pid);