Commit 81ab4201 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
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mm: add VM counters for transparent hugepages 



I found it difficult to make sense of transparent huge pages without
having any counters for its actions.  Add some counters to vmstat for
allocation of transparent hugepages and fallback to smaller pages.

Optional patch, but useful for development and understanding the system.

Contains improvements from Andrea Arcangeli and Johannes Weiner

[akpm@linux-foundation.org: coding-style fixes]
[hannes@cmpxchg.org: fix vmstat_text[] entries]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c897401b

include/linux/vmstat.h

+7 −0
Original line number Diff line number Diff line
@@ -58,6 +58,13 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, 
		UNEVICTABLE_PGCLEARED,	/* on COW, page truncate */

		UNEVICTABLE_PGSTRANDED,	/* unable to isolate on unlock */

		UNEVICTABLE_MLOCKFREED,

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

		THP_FAULT_ALLOC,

		THP_FAULT_FALLBACK,

		THP_COLLAPSE_ALLOC,

		THP_COLLAPSE_ALLOC_FAILED,

		THP_SPLIT,

#endif

		NR_VM_EVENT_ITEMS

};

mm/huge_memory.c

+21 −4
Original line number Diff line number Diff line
@@ -680,8 +680,11 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, 
			return VM_FAULT_OOM;

		page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),

					  vma, haddr, numa_node_id(), 0);

		if (unlikely(!page))

		if (unlikely(!page)) {

			count_vm_event(THP_FAULT_FALLBACK);

			goto out;

		}

		count_vm_event(THP_FAULT_ALLOC);

		if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {

			put_page(page);

			goto out;
@@ -909,11 +912,13 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, 
		new_page = NULL;



	if (unlikely(!new_page)) {

		count_vm_event(THP_FAULT_FALLBACK);

		ret = do_huge_pmd_wp_page_fallback(mm, vma, address,

						   pmd, orig_pmd, page, haddr);

		put_page(page);

		goto out;

	}

	count_vm_event(THP_FAULT_ALLOC);



	if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {

		put_page(new_page);
@@ -1390,6 +1395,7 @@ int split_huge_page(struct page *page) 


	BUG_ON(!PageSwapBacked(page));

	__split_huge_page(page, anon_vma);

	count_vm_event(THP_SPLIT);



	BUG_ON(PageCompound(page));

out_unlock:
@@ -1784,9 +1790,11 @@ static void collapse_huge_page(struct mm_struct *mm, 
				      node, __GFP_OTHER_NODE);

	if (unlikely(!new_page)) {

		up_read(&mm->mmap_sem);

		count_vm_event(THP_COLLAPSE_ALLOC_FAILED);

		*hpage = ERR_PTR(-ENOMEM);

		return;

	}

	count_vm_event(THP_COLLAPSE_ALLOC);

	if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {

		up_read(&mm->mmap_sem);

		put_page(new_page);
@@ -2151,9 +2159,12 @@ static void khugepaged_do_scan(struct page **hpage) 
#ifndef CONFIG_NUMA

		if (!*hpage) {

			*hpage = alloc_hugepage(khugepaged_defrag());

			if (unlikely(!*hpage))

			if (unlikely(!*hpage)) {

				count_vm_event(THP_COLLAPSE_ALLOC_FAILED);

				break;

			}

			count_vm_event(THP_COLLAPSE_ALLOC);

		}

#else

		if (IS_ERR(*hpage))

			break;
@@ -2192,8 +2203,11 @@ static struct page *khugepaged_alloc_hugepage(void) 


	do {

		hpage = alloc_hugepage(khugepaged_defrag());

		if (!hpage)

		if (!hpage) {

			count_vm_event(THP_COLLAPSE_ALLOC_FAILED);

			khugepaged_alloc_sleep();

		} else

			count_vm_event(THP_COLLAPSE_ALLOC);

	} while (unlikely(!hpage) &&

		 likely(khugepaged_enabled()));

	return hpage;
@@ -2210,8 +2224,11 @@ static void khugepaged_loop(void) 
	while (likely(khugepaged_enabled())) {

#ifndef CONFIG_NUMA

		hpage = khugepaged_alloc_hugepage();

		if (unlikely(!hpage))

		if (unlikely(!hpage)) {

			count_vm_event(THP_COLLAPSE_ALLOC_FAILED);

			break;

		}

		count_vm_event(THP_COLLAPSE_ALLOC);

#else

		if (IS_ERR(hpage)) {

			khugepaged_alloc_sleep();

mm/vmstat.c

+9 −0
Original line number Diff line number Diff line
@@ -948,7 +948,16 @@ static const char * const vmstat_text[] = { 
	"unevictable_pgs_cleared",

	"unevictable_pgs_stranded",

	"unevictable_pgs_mlockfreed",



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	"thp_fault_alloc",

	"thp_fault_fallback",

	"thp_collapse_alloc",

	"thp_collapse_alloc_failed",

	"thp_split",

#endif



#endif /* CONFIG_VM_EVENTS_COUNTERS */

};



static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,

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