From: "Matthew Wilcox (Oracle)" <willy@infradead.org> mainline inclusion from mainline-v6.9-rc1 commit 90491d87dd46a4c843dae775b9e72c91624c5a7b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9R3AY CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Iterate over a folio_batch rather than a linked list. This is easier for the CPU to prefetch and has a batch count naturally built in so we don't need to track it. Again, this lowers the maximum lock hold time from 32 folios to 15, but I do not expect this to have a significant effect. Link: https://lkml.kernel.org/r/20240227174254.710559-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: mm/page_alloc.c [ Conflicts with dynamic pool, fix the code in free_unref_page_list(). ] Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- mm/internal.h | 5 +++-- mm/page_alloc.c | 60 +++++++++++++++++++++++++++++-------------------- 2 files changed, 39 insertions(+), 26 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 6451747b7160..9d02b5a630e4 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -635,8 +635,9 @@ extern void dpool_prep_new_page(struct page *page, unsigned int order, #endif extern int user_min_free_kbytes; -extern void free_unref_page(struct page *page, unsigned int order); -extern void free_unref_page_list(struct list_head *list); +void free_unref_page(struct page *page, unsigned int order); +void free_unref_folios(struct folio_batch *fbatch); +void free_unref_page_list(struct list_head *list); extern void zone_pcp_reset(struct zone *zone); extern void zone_pcp_disable(struct zone *zone); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 27f13b34760a..4e0a11a0b62a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -32,6 +32,7 @@ #include <linux/sysctl.h> #include <linux/cpu.h> #include <linux/cpuset.h> +#include <linux/pagevec.h> #include <linux/memory_hotplug.h> #include <linux/nodemask.h> #include <linux/vmstat.h> @@ -2554,64 +2555,57 @@ void free_unref_page(struct page *page, unsigned int order) } /* - * Free a list of 0-order pages + * Free a batch of 0-order pages */ -void free_unref_page_list(struct list_head *list) +void free_unref_folios(struct folio_batch *folios) { unsigned long __maybe_unused UP_flags; - struct folio *folio, *next; struct per_cpu_pages *pcp = NULL; struct zone *locked_zone = NULL; - int batch_count = 0; - int migratetype; + int i, j, migratetype; - /* Prepare pages for freeing */ - list_for_each_entry_safe(folio, next, list, lru) { + /* Prepare folios for freeing */ + for (i = 0, j = 0; i < folios->nr; i++) { + struct folio *folio = folios->folios[i]; unsigned long pfn = folio_pfn(folio); if (page_from_dynamic_pool(&folio->page)) { - list_del(&folio->lru); dynamic_pool_free_page(&folio->page); continue; } - if (!free_unref_page_prepare(&folio->page, pfn, 0)) { - list_del(&folio->lru); + if (!free_unref_page_prepare(&folio->page, pfn, 0)) continue; - } /* - * Free isolated pages directly to the allocator, see + * Free isolated folios directly to the allocator, see * comment in free_unref_page. */ migratetype = get_pcppage_migratetype(&folio->page); if (unlikely(is_migrate_isolate(migratetype))) { - list_del(&folio->lru); free_one_page(folio_zone(folio), &folio->page, pfn, 0, migratetype, FPI_NONE); continue; } + if (j != i) + folios->folios[j] = folio; + j++; } + folios->nr = j; - list_for_each_entry_safe(folio, next, list, lru) { + for (i = 0; i < folios->nr; i++) { + struct folio *folio = folios->folios[i]; struct zone *zone = folio_zone(folio); - list_del(&folio->lru); migratetype = get_pcppage_migratetype(&folio->page); - /* - * Either different zone requiring a different pcp lock or - * excessive lock hold times when freeing a large list of - * folios. - */ - if (zone != locked_zone || batch_count == SWAP_CLUSTER_MAX) { + /* Different zone requires a different pcp lock */ + if (zone != locked_zone) { if (pcp) { pcp_spin_unlock(pcp); pcp_trylock_finish(UP_flags); } - batch_count = 0; - /* * trylock is necessary as folios may be getting freed * from IRQ or SoftIRQ context after an IO completion. @@ -2638,13 +2632,31 @@ void free_unref_page_list(struct list_head *list) trace_mm_page_free_batched(&folio->page); free_unref_page_commit(zone, pcp, &folio->page, migratetype, 0); - batch_count++; } if (pcp) { pcp_spin_unlock(pcp); pcp_trylock_finish(UP_flags); } + folio_batch_reinit(folios); +} + +void free_unref_page_list(struct list_head *list) +{ + struct folio_batch fbatch; + + folio_batch_init(&fbatch); + while (!list_empty(list)) { + struct folio *folio = list_first_entry(list, struct folio, lru); + + list_del(&folio->lru); + if (folio_batch_add(&fbatch, folio) > 0) + continue; + free_unref_folios(&fbatch); + } + + if (fbatch.nr) + free_unref_folios(&fbatch); } /* -- 2.25.1