All of lore.kernel.org
 help / color / mirror / Atom feed
From: cgel.zte@gmail.com
To: akpm@linux-foundation.org, yang.shi@linux.alibaba.com,
	ying.huang@intel.com
Cc: dave.hansen@linux.intel.com, yang.yang29@zte.com.cn,
	minchan@kernel.org, saravanand@fb.com,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH] mm/vmstat: add events for THP max_ptes_* exceeds
Date: Sat, 25 Dec 2021 09:40:37 +0000	[thread overview]
Message-ID: <20211225094036.574157-1-yang.yang29@zte.com.cn> (raw)

From: Yang Yang <yang.yang29@zte.com.cn>

There are interfaces to adjust max_ptes_none, max_ptes_swap,
max_ptes_shared values, see
/sys/kernel/mm/transparent_hugepage/khugepaged/.

But system administrator maynot know which value is the best. So
Add those events to support adjusting max_ptes_* to suitable values.

For example, if default max_ptes_swap value causes too much failures,
and system uses zram whose IO is fast, administrator could increase
max_ptes_swap until THP_SCAN_EXCEED_SWAP_PTE not increase anymore.

Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
---
 include/linux/vm_event_item.h | 3 +++
 mm/khugepaged.c               | 7 +++++++
 mm/vmstat.c                   | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index a185cc75ff52..7b2363388bfa 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -98,6 +98,9 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 		THP_SPLIT_PAGE_FAILED,
 		THP_DEFERRED_SPLIT_PAGE,
 		THP_SPLIT_PMD,
+		THP_SCAN_EXCEED_NONE_PTE,
+		THP_SCAN_EXCEED_SWAP_PTE,
+		THP_SCAN_EXCEED_SHARED_PTE,
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 		THP_SPLIT_PUD,
 #endif
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 7720189a2da7..abcd6bd8b97a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -618,6 +618,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 				continue;
 			} else {
 				result = SCAN_EXCEED_NONE_PTE;
+				count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
 				goto out;
 			}
 		}
@@ -636,6 +637,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 		if (page_mapcount(page) > 1 &&
 				++shared > khugepaged_max_ptes_shared) {
 			result = SCAN_EXCEED_SHARED_PTE;
+			count_vm_event(THP_SCAN_EXCEED_SHARED_PTE);
 			goto out;
 		}
 
@@ -1253,6 +1255,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 				continue;
 			} else {
 				result = SCAN_EXCEED_SWAP_PTE;
+				count_vm_event(THP_SCAN_EXCEED_SWAP_PTE);
 				goto out_unmap;
 			}
 		}
@@ -1262,6 +1265,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 				continue;
 			} else {
 				result = SCAN_EXCEED_NONE_PTE;
+				count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
 				goto out_unmap;
 			}
 		}
@@ -1290,6 +1294,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 		if (page_mapcount(page) > 1 &&
 				++shared > khugepaged_max_ptes_shared) {
 			result = SCAN_EXCEED_SHARED_PTE;
+			count_vm_event(THP_SCAN_EXCEED_SHARED_PTE);
 			goto out_unmap;
 		}
 
@@ -2006,6 +2011,7 @@ static void khugepaged_scan_file(struct mm_struct *mm,
 		if (xa_is_value(page)) {
 			if (++swap > khugepaged_max_ptes_swap) {
 				result = SCAN_EXCEED_SWAP_PTE;
+				count_vm_event(THP_SCAN_EXCEED_SWAP_PTE);
 				break;
 			}
 			continue;
@@ -2056,6 +2062,7 @@ static void khugepaged_scan_file(struct mm_struct *mm,
 	if (result == SCAN_SUCCEED) {
 		if (present < HPAGE_PMD_NR - khugepaged_max_ptes_none) {
 			result = SCAN_EXCEED_NONE_PTE;
+			count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
 		} else {
 			node = khugepaged_find_target_node();
 			collapse_file(mm, file, start, hpage, node);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index d701c335628c..4057372745d0 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1353,6 +1353,9 @@ const char * const vmstat_text[] = {
 	"thp_split_page_failed",
 	"thp_deferred_split_page",
 	"thp_split_pmd",
+	"thp_scan_exceed_none_pte",
+	"thp_scan_exceed_swap_pte",
+	"thp_scan_exceed_share_pte",
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 	"thp_split_pud",
 #endif
-- 
2.25.1


             reply	other threads:[~2021-12-25  9:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-25  9:40 cgel.zte [this message]
2021-12-27  3:19 ` [PATCH] mm/vmstat: add events for THP max_ptes_* exceeds Huang, Ying
2021-12-27  3:59   ` CGEL

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211225094036.574157-1-yang.yang29@zte.com.cn \
    --to=cgel.zte@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=dave.hansen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=minchan@kernel.org \
    --cc=saravanand@fb.com \
    --cc=yang.shi@linux.alibaba.com \
    --cc=yang.yang29@zte.com.cn \
    --cc=ying.huang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.