From 70dea5346ea327499f9a71e77bec2732e4d422ed Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 17 Jun 2022 18:50:02 +0100 Subject: mm/swap: convert lru_add to a folio_batch When adding folios to the LRU for the first time, the LRU flag will already be clear, so skip the test-and-clear part of moving from one LRU to another. Removes 285 bytes from kernel text, mostly due to removing __pagevec_lru_add(). Link: https://lkml.kernel.org/r/20220617175020.717127-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/swap.c | 75 ++++++++++++++++++++++----------------------------------------- 1 file changed, 26 insertions(+), 49 deletions(-) (limited to 'mm/swap.c') diff --git a/mm/swap.c b/mm/swap.c index cab77a5c64c7..cb7669bea85b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -61,7 +61,7 @@ static DEFINE_PER_CPU(struct lru_rotate, lru_rotate) = { */ struct lru_pvecs { local_lock_t lock; - struct pagevec lru_add; + struct folio_batch lru_add; struct pagevec lru_deactivate_file; struct pagevec lru_deactivate; struct pagevec lru_lazyfree; @@ -228,14 +228,13 @@ static bool pagevec_add_and_need_flush(struct pagevec *pvec, struct page *page) typedef void (*move_fn_t)(struct lruvec *lruvec, struct folio *folio); -static void __pagevec_lru_add_fn(struct folio *folio, struct lruvec *lruvec) +static void lru_add_fn(struct lruvec *lruvec, struct folio *folio) { int was_unevictable = folio_test_clear_unevictable(folio); long nr_pages = folio_nr_pages(folio); VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); - folio_set_lru(folio); /* * Is an smp_mb__after_atomic() still required here, before * folio_evictable() tests PageMlocked, to rule out the possibility @@ -269,28 +268,6 @@ static void __pagevec_lru_add_fn(struct folio *folio, struct lruvec *lruvec) trace_mm_lru_insertion(folio); } -/* - * Add the passed pages to the LRU, then drop the caller's refcount - * on them. Reinitialises the caller's pagevec. - */ -static void __pagevec_lru_add(struct pagevec *pvec) -{ - int i; - struct lruvec *lruvec = NULL; - unsigned long flags = 0; - - for (i = 0; i < pagevec_count(pvec); i++) { - struct folio *folio = page_folio(pvec->pages[i]); - - lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags); - __pagevec_lru_add_fn(folio, lruvec); - } - if (lruvec) - unlock_page_lruvec_irqrestore(lruvec, flags); - release_pages(pvec->pages, pvec->nr); - pagevec_reinit(pvec); -} - static void folio_batch_move_lru(struct folio_batch *fbatch, move_fn_t move_fn) { int i; @@ -301,7 +278,7 @@ static void folio_batch_move_lru(struct folio_batch *fbatch, move_fn_t move_fn) struct folio *folio = fbatch->folios[i]; /* block memcg migration while the folio moves between lru */ - if (!folio_test_clear_lru(folio)) + if (move_fn != lru_add_fn && !folio_test_clear_lru(folio)) continue; lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags); @@ -473,26 +450,26 @@ static void folio_activate(struct folio *folio) static void __lru_cache_activate_folio(struct folio *folio) { - struct pagevec *pvec; + struct folio_batch *fbatch; int i; local_lock(&lru_pvecs.lock); - pvec = this_cpu_ptr(&lru_pvecs.lru_add); + fbatch = this_cpu_ptr(&lru_pvecs.lru_add); /* - * Search backwards on the optimistic assumption that the page being - * activated has just been added to this pagevec. Note that only - * the local pagevec is examined as a !PageLRU page could be in the + * Search backwards on the optimistic assumption that the folio being + * activated has just been added to this batch. Note that only + * the local batch is examined as a !LRU folio could be in the * process of being released, reclaimed, migrated or on a remote - * pagevec that is currently being drained. Furthermore, marking - * a remote pagevec's page PageActive potentially hits a race where - * a page is marked PageActive just after it is added to the inactive + * batch that is currently being drained. Furthermore, marking + * a remote batch's folio active potentially hits a race where + * a folio is marked active just after it is added to the inactive * list causing accounting errors and BUG_ON checks to trigger. */ - for (i = pagevec_count(pvec) - 1; i >= 0; i--) { - struct page *pagevec_page = pvec->pages[i]; + for (i = folio_batch_count(fbatch) - 1; i >= 0; i--) { + struct folio *batch_folio = fbatch->folios[i]; - if (pagevec_page == &folio->page) { + if (batch_folio == folio) { folio_set_active(folio); break; } @@ -551,16 +528,16 @@ EXPORT_SYMBOL(folio_mark_accessed); */ void folio_add_lru(struct folio *folio) { - struct pagevec *pvec; + struct folio_batch *fbatch; - VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio); + VM_BUG_ON_FOLIO(folio_test_active(folio) && + folio_test_unevictable(folio), folio); VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); folio_get(folio); local_lock(&lru_pvecs.lock); - pvec = this_cpu_ptr(&lru_pvecs.lru_add); - if (pagevec_add_and_need_flush(pvec, &folio->page)) - __pagevec_lru_add(pvec); + fbatch = this_cpu_ptr(&lru_pvecs.lru_add); + folio_batch_add_and_move(fbatch, folio, lru_add_fn); local_unlock(&lru_pvecs.lock); } EXPORT_SYMBOL(folio_add_lru); @@ -691,11 +668,11 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec) */ void lru_add_drain_cpu(int cpu) { - struct folio_batch *fbatch; - struct pagevec *pvec = &per_cpu(lru_pvecs.lru_add, cpu); + struct folio_batch *fbatch = &per_cpu(lru_pvecs.lru_add, cpu); + struct pagevec *pvec; - if (pagevec_count(pvec)) - __pagevec_lru_add(pvec); + if (folio_batch_count(fbatch)) + folio_batch_move_lru(fbatch, lru_add_fn); fbatch = &per_cpu(lru_rotate.fbatch, cpu); /* Disabling interrupts below acts as a compiler barrier. */ @@ -920,7 +897,7 @@ static inline void __lru_add_drain_all(bool force_all_cpus) for_each_online_cpu(cpu) { struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); - if (pagevec_count(&per_cpu(lru_pvecs.lru_add, cpu)) || + if (folio_batch_count(&per_cpu(lru_pvecs.lru_add, cpu)) || data_race(folio_batch_count(&per_cpu(lru_rotate.fbatch, cpu))) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) || @@ -1084,8 +1061,8 @@ EXPORT_SYMBOL(release_pages); * OK from a correctness point of view but is inefficient - those pages may be * cache-warm and we want to give them back to the page allocator ASAP. * - * So __pagevec_release() will drain those queues here. __pagevec_lru_add() - * and __pagevec_lru_add_active() call release_pages() directly to avoid + * So __pagevec_release() will drain those queues here. + * folio_batch_move_lru() calls folios_put() directly to avoid * mutual recursion. */ void __pagevec_release(struct pagevec *pvec) -- cgit v1.2.3