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mm: migrate: correct the hugetlb migration stats

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Correct the migration stats for hugetlb with using compound_nr() instead
of thp_nr_pages(), meanwhile change 'nr_failed_pages' to record the
number of normal pages failed to migrate, including THP and hugetlb, and
'nr_succeeded' will record the number of normal pages migrated
successfully.

[baolin.wang@linux.alibaba.com: fix docs, per Mike]
  Link: https://lkml.kernel.org/r/141bdfc6-f898-3cc3-f692-726c5f6cb74d@linux.alibaba.com

Link: https://lkml.kernel.org/r/71a4b6c22f208728fe8c78ad26375436c4ff9704.1636275127.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Baolin Wang 2022-01-14 14:08:37 -08:00 committed by Linus Torvalds
parent b5bade978e
commit 5d39a7ebc8
2 changed files with 14 additions and 15 deletions
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12
Documentation/vm/page_migration.rst
View File

@ -263,15 +263,15 @@ Monitoring Migration
The following events (counters) can be used to monitor page migration.
1. PGMIGRATE_SUCCESS: Normal page migration success. Each count means that a
page was migrated. If the page was a non-THP page, then this counter is
increased by one. If the page was a THP, then this counter is increased by
the number of THP subpages. For example, migration of a single 2MB THP that
has 4KB-size base pages (subpages) will cause this counter to increase by
512.
page was migrated. If the page was a non-THP and non-hugetlb page, then
this counter is increased by one. If the page was a THP or hugetlb, then
this counter is increased by the number of THP or hugetlb subpages.
For example, migration of a single 2MB THP that has 4KB-size base pages
(subpages) will cause this counter to increase by 512.
2. PGMIGRATE_FAIL: Normal page migration failure. Same counting rules as for
PGMIGRATE_SUCCESS, above: this will be increased by the number of subpages,
if it was a THP.
if it was a THP or hugetlb.
3. THP_MIGRATION_SUCCESS: A THP was migrated without being split.

17
mm/migrate.c
View File

@ -1429,9 +1429,9 @@ static inline int try_split_thp(struct page *page, struct page **page2,
* It is caller's responsibility to call putback_movable_pages() to return pages
* to the LRU or free list only if ret != 0.
*
* Returns the number of {normal page, THP} that were not migrated, or an error code.
* The number of THP splits will be considered as the number of non-migrated THP,
* no matter how many subpages of the THP are migrated successfully.
* Returns the number of {normal page, THP, hugetlb} that were not migrated, or
* an error code. The number of THP splits will be considered as the number of
* non-migrated THP, no matter how many subpages of the THP are migrated successfully.
*/
int migrate_pages(struct list_head *from, new_page_t get_new_page,
free_page_t put_new_page, unsigned long private,
@ -1474,7 +1474,7 @@ retry:
* during migration.
*/
is_thp = PageTransHuge(page) && !PageHuge(page);
nr_subpages = thp_nr_pages(page);
nr_subpages = compound_nr(page);
cond_resched();
if (PageHuge(page))
@ -1523,7 +1523,7 @@ retry:
/* Hugetlb migration is unsupported */
if (!no_subpage_counting)
nr_failed++;
nr_failed_pages++;
nr_failed_pages += nr_subpages;
break;
case -ENOMEM:
/*
@ -1544,7 +1544,7 @@ retry:
if (!no_subpage_counting)
nr_failed++;
nr_failed_pages++;
nr_failed_pages += nr_subpages;
goto out;
case -EAGAIN:
if (is_thp) {
@ -1554,12 +1554,11 @@ retry:
retry++;
break;
case MIGRATEPAGE_SUCCESS:
nr_succeeded += nr_subpages;
if (is_thp) {
nr_thp_succeeded++;
nr_succeeded += nr_subpages;
break;
}
nr_succeeded++;
break;
default:
/*
@ -1576,7 +1575,7 @@ retry:
if (!no_subpage_counting)
nr_failed++;
nr_failed_pages++;
nr_failed_pages += nr_subpages;
break;
}
}