diff options
Diffstat (limited to 'mm/swap.c')
| -rw-r--r-- | mm/swap.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/mm/swap.c b/mm/swap.c index 38c3fa4308e2..5341ae93861f 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -373,9 +373,16 @@ static void __lru_cache_activate_page(struct page *page) void mark_page_accessed(struct page *page) { page = compound_head(page); - if (!PageActive(page) && !PageUnevictable(page) && - PageReferenced(page)) { + if (!PageReferenced(page)) { + SetPageReferenced(page); + } else if (PageUnevictable(page)) { + /* + * Unevictable pages are on the "LRU_UNEVICTABLE" list. But, + * this list is never rotated or maintained, so marking an + * evictable page accessed has no effect. + */ + } else if (!PageActive(page)) { /* * If the page is on the LRU, queue it for activation via * activate_page_pvecs. Otherwise, assume the page is on a @@ -389,8 +396,6 @@ void mark_page_accessed(struct page *page) ClearPageReferenced(page); if (page_is_file_cache(page)) workingset_activation(page); - } else if (!PageReferenced(page)) { - SetPageReferenced(page); } if (page_is_idle(page)) clear_page_idle(page); @@ -708,9 +713,10 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) */ void lru_add_drain_all(void) { + static seqcount_t seqcount = SEQCNT_ZERO(seqcount); static DEFINE_MUTEX(lock); static struct cpumask has_work; - int cpu; + int cpu, seq; /* * Make sure nobody triggers this path before mm_percpu_wq is fully @@ -719,7 +725,19 @@ void lru_add_drain_all(void) if (WARN_ON(!mm_percpu_wq)) return; + seq = raw_read_seqcount_latch(&seqcount); + mutex_lock(&lock); + + /* + * Piggyback on drain started and finished while we waited for lock: + * all pages pended at the time of our enter were drained from vectors. + */ + if (__read_seqcount_retry(&seqcount, seq)) + goto done; + + raw_write_seqcount_latch(&seqcount); + cpumask_clear(&has_work); for_each_online_cpu(cpu) { @@ -740,6 +758,7 @@ void lru_add_drain_all(void) for_each_cpu(cpu, &has_work) flush_work(&per_cpu(lru_add_drain_work, cpu)); +done: mutex_unlock(&lock); } #else |