Use a folio in migrate_misplaced_page() to save compound_head() calls.
Signed-off-by: Kefeng Wang <[email protected]>
---
mm/migrate.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 281eafdf8e63..fc728f9a383f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2521,17 +2521,18 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
int node)
{
pg_data_t *pgdat = NODE_DATA(node);
+ struct folio *folio = page_folio(page);
int isolated;
int nr_remaining;
unsigned int nr_succeeded;
LIST_HEAD(migratepages);
- int nr_pages = thp_nr_pages(page);
+ int nr_pages = folio_nr_pages(folio);
/*
* Don't migrate file pages that are mapped in multiple processes
* with execute permissions as they are probably shared libraries.
*/
- if (page_mapcount(page) != 1 && page_is_file_lru(page) &&
+ if (page_mapcount(page) != 1 && folio_is_file_lru(folio) &&
(vma->vm_flags & VM_EXEC))
goto out;
@@ -2539,29 +2540,29 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
* Also do not migrate dirty pages as not all filesystems can move
* dirty pages in MIGRATE_ASYNC mode which is a waste of cycles.
*/
- if (page_is_file_lru(page) && PageDirty(page))
+ if (folio_is_file_lru(folio) && folio_test_dirty(folio))
goto out;
- isolated = numamigrate_isolate_folio(pgdat, page_folio(page));
+ isolated = numamigrate_isolate_folio(pgdat, folio);
if (!isolated)
goto out;
- list_add(&page->lru, &migratepages);
+ list_add(&folio->lru, &migratepages);
nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_folio,
NULL, node, MIGRATE_ASYNC,
MR_NUMA_MISPLACED, &nr_succeeded);
if (nr_remaining) {
if (!list_empty(&migratepages)) {
- list_del(&page->lru);
- mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
- page_is_file_lru(page), -nr_pages);
- putback_lru_page(page);
+ list_del(&folio->lru);
+ node_stat_mod_folio(folio, NR_ISOLATED_ANON +
+ folio_is_file_lru(folio), -nr_pages);
+ folio_putback_lru(folio);
}
isolated = 0;
}
if (nr_succeeded) {
count_vm_numa_events(NUMA_PAGE_MIGRATE, nr_succeeded);
- if (!node_is_toptier(page_to_nid(page)) && node_is_toptier(node))
+ if (!node_is_toptier(folio_nid(folio)) && node_is_toptier(node))
mod_node_page_state(pgdat, PGPROMOTE_SUCCESS,
nr_succeeded);
}
@@ -2569,7 +2570,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
return isolated;
out:
- put_page(page);
+ folio_put(folio);
return 0;
}
#endif /* CONFIG_NUMA_BALANCING */
--
2.41.0
On 2023/8/29 10:10, Matthew Wilcox wrote:
> On Tue, Aug 29, 2023 at 08:49:31AM +0800, Huang, Ying wrote:
>> Zi Yan <[email protected]> writes:
>>
>>> On 21 Aug 2023, at 7:56, Kefeng Wang wrote:
>>>
>>>> Use a folio in migrate_misplaced_page() to save compound_head() calls.
>>>>
>>>> Signed-off-by: Kefeng Wang <[email protected]>
>>>> ---
>>>> mm/migrate.c | 23 ++++++++++++-----------
>>>> 1 file changed, 12 insertions(+), 11 deletions(-)
>>>
>>> LGTM. And a comment below. Reveiwed-by: Zi Yan <[email protected]>
>>>
>>>>
>>>> diff --git a/mm/migrate.c b/mm/migrate.c
>>>> index 281eafdf8e63..fc728f9a383f 100644
>>>> --- a/mm/migrate.c
>>>> +++ b/mm/migrate.c
>>>> @@ -2521,17 +2521,18 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
>>>> int node)
>>>> {
>>>> pg_data_t *pgdat = NODE_DATA(node);
>>>> + struct folio *folio = page_folio(page);
>>>> int isolated;
>>>> int nr_remaining;
>>>> unsigned int nr_succeeded;
>>>> LIST_HEAD(migratepages);
>>>> - int nr_pages = thp_nr_pages(page);
>>>> + int nr_pages = folio_nr_pages(folio);
>>>>
>>>> /*
>>>> * Don't migrate file pages that are mapped in multiple processes
>>>> * with execute permissions as they are probably shared libraries.
>>>> */
>>>> - if (page_mapcount(page) != 1 && page_is_file_lru(page) &&
>>>> + if (page_mapcount(page) != 1 && folio_is_file_lru(folio) &&
>>>
>>> page_mapcount() is not converted, since folio_mapcount() is not equivalent
>>> to page_mapcount(). It can be converted and this function can be converted
>>> to migrate_misplaced_folio() once we have something like folio_num_sharers().
>>
>> It seems that we can use folio_estimated_sharers() here.
>
> So, funny thing, page_mapcount() was always wrong here. We have two
> callers, do_huge_pmd_numa_page() and do_numa_page(). do_numa_page()
> has a check for PageCompound() (and /* TODO: handle PTE-mapped THP */).
> do_huge_pmd_numa_page() returns pfn_to_page(), after it got the pfn
> fromm pmd_pfn(pmd).
for PMD-mapped page，do_huge_pmd_numa_page() return head page
unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
page = vm_normal_page_pmd(vma, haddr, pmd);
do_numa_page() only handle base page with PageCompound() check， so we
could use folio_estimated_sharers()， I am not clear why page_mapcount
is wrong here, could you explain more, thank.
>
> That makes folio_estimated_sharers() an improvement, possibly even
> a bugfix. Also, we should look at removing the PageCompound() check
> in do_numa_page().
Yes, for pte-mapped thp and the large folio numa migrate support, we
need remove the check, we could do it in another patchset.
>
>