6.1-stable review patch. If anyone has any objections, please let me know.
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From: Huang Ying ying.huang@intel.com
[ Upstream commit eaec4e639f11413ce75fbf38affd1aa5c40979e9 ]
Quite straightforward, the page functions are converted to corresponding folio functions. Same for comments.
THP specific code are converted to be large folio.
Link: https://lkml.kernel.org/r/20221109012348.93849-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" ying.huang@intel.com Reviewed-by: Baolin Wang baolin.wang@linux.alibaba.com Tested-by: Baolin Wang baolin.wang@linux.alibaba.com Cc: Zi Yan ziy@nvidia.com Cc: Yang Shi shy828301@gmail.com Cc: Oscar Salvador osalvador@suse.de Cc: Matthew Wilcox willy@infradead.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 35e41024c4c2 ("vmscan,migrate: fix page count imbalance on node stats when demoting pages") Signed-off-by: Sasha Levin sashal@kernel.org --- mm/migrate.c | 210 +++++++++++++++++++++++++++------------------------ 1 file changed, 112 insertions(+), 98 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 16b456b927c18..562f819dc6189 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1385,231 +1385,245 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, return rc; }
-static inline int try_split_thp(struct page *page, struct list_head *split_pages) +static inline int try_split_folio(struct folio *folio, struct list_head *split_folios) { int rc;
- lock_page(page); - rc = split_huge_page_to_list(page, split_pages); - unlock_page(page); + folio_lock(folio); + rc = split_folio_to_list(folio, split_folios); + folio_unlock(folio); if (!rc) - list_move_tail(&page->lru, split_pages); + list_move_tail(&folio->lru, split_folios);
return rc; }
/* - * migrate_pages - migrate the pages specified in a list, to the free pages + * migrate_pages - migrate the folios specified in a list, to the free folios * supplied as the target for the page migration * - * @from: The list of pages to be migrated. - * @get_new_page: The function used to allocate free pages to be used - * as the target of the page migration. - * @put_new_page: The function used to free target pages if migration + * @from: The list of folios to be migrated. + * @get_new_page: The function used to allocate free folios to be used + * as the target of the folio migration. + * @put_new_page: The function used to free target folios if migration * fails, or NULL if no special handling is necessary. * @private: Private data to be passed on to get_new_page() * @mode: The migration mode that specifies the constraints for - * page migration, if any. - * @reason: The reason for page migration. - * @ret_succeeded: Set to the number of normal pages migrated successfully if + * folio migration, if any. + * @reason: The reason for folio migration. + * @ret_succeeded: Set to the number of folios migrated successfully if * the caller passes a non-NULL pointer. * - * The function returns after 10 attempts or if no pages are movable any more - * because the list has become empty or no retryable pages exist any more. - * It is caller's responsibility to call putback_movable_pages() to return pages + * The function returns after 10 attempts or if no folios are movable any more + * because the list has become empty or no retryable folios exist any more. + * It is caller's responsibility to call putback_movable_pages() to return folios * to the LRU or free list only if ret != 0. * - * 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. + * Returns the number of {normal folio, large folio, hugetlb} that were not + * migrated, or an error code. The number of large folio splits will be + * considered as the number of non-migrated large folio, no matter how many + * split folios of the large folio 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, enum migrate_mode mode, int reason, unsigned int *ret_succeeded) { int retry = 1; + int large_retry = 1; int thp_retry = 1; int nr_failed = 0; int nr_failed_pages = 0; int nr_retry_pages = 0; int nr_succeeded = 0; int nr_thp_succeeded = 0; + int nr_large_failed = 0; int nr_thp_failed = 0; int nr_thp_split = 0; int pass = 0; + bool is_large = false; bool is_thp = false; - struct page *page; - struct page *page2; - int rc, nr_subpages; - LIST_HEAD(ret_pages); - LIST_HEAD(thp_split_pages); + struct folio *folio, *folio2; + int rc, nr_pages; + LIST_HEAD(ret_folios); + LIST_HEAD(split_folios); bool nosplit = (reason == MR_NUMA_MISPLACED); - bool no_subpage_counting = false; + bool no_split_folio_counting = false;
trace_mm_migrate_pages_start(mode, reason);
-thp_subpage_migration: - for (pass = 0; pass < 10 && (retry || thp_retry); pass++) { +split_folio_migration: + for (pass = 0; pass < 10 && (retry || large_retry); pass++) { retry = 0; + large_retry = 0; thp_retry = 0; nr_retry_pages = 0;
- list_for_each_entry_safe(page, page2, from, lru) { + list_for_each_entry_safe(folio, folio2, from, lru) { /* - * THP statistics is based on the source huge page. - * Capture required information that might get lost - * during migration. + * Large folio statistics is based on the source large + * folio. Capture required information that might get + * lost during migration. */ - is_thp = PageTransHuge(page) && !PageHuge(page); - nr_subpages = compound_nr(page); + is_large = folio_test_large(folio) && !folio_test_hugetlb(folio); + is_thp = is_large && folio_test_pmd_mappable(folio); + nr_pages = folio_nr_pages(folio); cond_resched();
- if (PageHuge(page)) + if (folio_test_hugetlb(folio)) rc = unmap_and_move_huge_page(get_new_page, - put_new_page, private, page, - pass > 2, mode, reason, - &ret_pages); + put_new_page, private, + &folio->page, pass > 2, mode, + reason, + &ret_folios); else rc = unmap_and_move(get_new_page, put_new_page, - private, page_folio(page), pass > 2, mode, - reason, &ret_pages); + private, folio, pass > 2, mode, + reason, &ret_folios); /* * The rules are: - * Success: non hugetlb page will be freed, hugetlb - * page will be put back + * Success: non hugetlb folio will be freed, hugetlb + * folio will be put back * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list * -ENOSYS: stay on the from list - * Other errno: put on ret_pages list then splice to + * Other errno: put on ret_folios list then splice to * from list */ switch(rc) { /* - * THP migration might be unsupported or the - * allocation could've failed so we should - * retry on the same page with the THP split - * to base pages. + * Large folio migration might be unsupported or + * the allocation could've failed so we should retry + * on the same folio with the large folio split + * to normal folios. * - * Sub-pages are put in thp_split_pages, and + * Split folios are put in split_folios, and * we will migrate them after the rest of the * list is processed. */ case -ENOSYS: - /* THP migration is unsupported */ - if (is_thp) { - nr_thp_failed++; - if (!try_split_thp(page, &thp_split_pages)) { - nr_thp_split++; + /* Large folio migration is unsupported */ + if (is_large) { + nr_large_failed++; + nr_thp_failed += is_thp; + if (!try_split_folio(folio, &split_folios)) { + nr_thp_split += is_thp; break; } /* Hugetlb migration is unsupported */ - } else if (!no_subpage_counting) { + } else if (!no_split_folio_counting) { nr_failed++; }
- nr_failed_pages += nr_subpages; - list_move_tail(&page->lru, &ret_pages); + nr_failed_pages += nr_pages; + list_move_tail(&folio->lru, &ret_folios); break; case -ENOMEM: /* * When memory is low, don't bother to try to migrate - * other pages, just exit. + * other folios, just exit. */ - if (is_thp) { - nr_thp_failed++; - /* THP NUMA faulting doesn't split THP to retry. */ + if (is_large) { + nr_large_failed++; + nr_thp_failed += is_thp; + /* Large folio NUMA faulting doesn't split to retry. */ if (!nosplit) { - int ret = try_split_thp(page, &thp_split_pages); + int ret = try_split_folio(folio, &split_folios);
if (!ret) { - nr_thp_split++; + nr_thp_split += is_thp; break; } else if (reason == MR_LONGTERM_PIN && ret == -EAGAIN) { /* - * Try again to split THP to mitigate - * the failure of longterm pinning. + * Try again to split large folio to + * mitigate the failure of longterm pinning. */ - thp_retry++; - nr_retry_pages += nr_subpages; + large_retry++; + thp_retry += is_thp; + nr_retry_pages += nr_pages; break; } } - } else if (!no_subpage_counting) { + } else if (!no_split_folio_counting) { nr_failed++; }
- nr_failed_pages += nr_subpages + nr_retry_pages; + nr_failed_pages += nr_pages + nr_retry_pages; /* - * There might be some subpages of fail-to-migrate THPs - * left in thp_split_pages list. Move them back to migration + * There might be some split folios of fail-to-migrate large + * folios left in split_folios list. Move them back to migration * list so that they could be put back to the right list by - * the caller otherwise the page refcnt will be leaked. + * the caller otherwise the folio refcnt will be leaked. */ - list_splice_init(&thp_split_pages, from); + list_splice_init(&split_folios, from); /* nr_failed isn't updated for not used */ + nr_large_failed += large_retry; nr_thp_failed += thp_retry; goto out; case -EAGAIN: - if (is_thp) - thp_retry++; - else if (!no_subpage_counting) + if (is_large) { + large_retry++; + thp_retry += is_thp; + } else if (!no_split_folio_counting) { retry++; - nr_retry_pages += nr_subpages; + } + nr_retry_pages += nr_pages; break; case MIGRATEPAGE_SUCCESS: - nr_succeeded += nr_subpages; - if (is_thp) - nr_thp_succeeded++; + nr_succeeded += nr_pages; + nr_thp_succeeded += is_thp; break; default: /* * Permanent failure (-EBUSY, etc.): - * unlike -EAGAIN case, the failed page is - * removed from migration page list and not + * unlike -EAGAIN case, the failed folio is + * removed from migration folio list and not * retried in the next outer loop. */ - if (is_thp) - nr_thp_failed++; - else if (!no_subpage_counting) + if (is_large) { + nr_large_failed++; + nr_thp_failed += is_thp; + } else if (!no_split_folio_counting) { nr_failed++; + }
- nr_failed_pages += nr_subpages; + nr_failed_pages += nr_pages; break; } } } nr_failed += retry; + nr_large_failed += large_retry; nr_thp_failed += thp_retry; nr_failed_pages += nr_retry_pages; /* - * Try to migrate subpages of fail-to-migrate THPs, no nr_failed - * counting in this round, since all subpages of a THP is counted - * as 1 failure in the first round. + * Try to migrate split folios of fail-to-migrate large folios, no + * nr_failed counting in this round, since all split folios of a + * large folio is counted as 1 failure in the first round. */ - if (!list_empty(&thp_split_pages)) { + if (!list_empty(&split_folios)) { /* - * Move non-migrated pages (after 10 retries) to ret_pages + * Move non-migrated folios (after 10 retries) to ret_folios * to avoid migrating them again. */ - list_splice_init(from, &ret_pages); - list_splice_init(&thp_split_pages, from); - no_subpage_counting = true; + list_splice_init(from, &ret_folios); + list_splice_init(&split_folios, from); + no_split_folio_counting = true; retry = 1; - goto thp_subpage_migration; + goto split_folio_migration; }
- rc = nr_failed + nr_thp_failed; + rc = nr_failed + nr_large_failed; out: /* - * Put the permanent failure page back to migration list, they + * Put the permanent failure folio back to migration list, they * will be put back to the right list by the caller. */ - list_splice(&ret_pages, from); + list_splice(&ret_folios, from);
/* - * Return 0 in case all subpages of fail-to-migrate THPs are - * migrated successfully. + * Return 0 in case all split folios of fail-to-migrate large folios + * are migrated successfully. */ if (list_empty(from)) rc = 0;