From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> As with shmem_tag_pins(), hold the lock around the entire loop instead of acquiring & dropping it for each entry we're going to untag. Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> --- mm/shmem.c | 59 +++++++++++++++++++++++++---------------------------------- 1 file changed, 25 insertions(+), 34 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 302fcb62ba1f..e4d28743a666 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2636,9 +2636,7 @@ static void shmem_tag_pins(struct address_space *mapping) */ static int shmem_wait_for_pins(struct address_space *mapping) { - struct radix_tree_iter iter; - void **slot; - pgoff_t start; + XA_STATE(xas, 0); struct page *page; int error, scan; @@ -2646,7 +2644,9 @@ static int shmem_wait_for_pins(struct address_space *mapping) error = 0; for (scan = 0; scan <= LAST_SCAN; scan++) { - if (!radix_tree_tagged(&mapping->pages, SHMEM_TAG_PINNED)) + unsigned int tagged = 0; + + if (!xa_tagged(&mapping->pages, SHMEM_TAG_PINNED)) break; if (!scan) @@ -2654,45 +2654,36 @@ static int shmem_wait_for_pins(struct address_space *mapping) else if (schedule_timeout_killable((HZ << scan) / 200)) scan = LAST_SCAN; - start = 0; - rcu_read_lock(); - radix_tree_for_each_tagged(slot, &mapping->pages, &iter, - start, SHMEM_TAG_PINNED) { - - page = radix_tree_deref_slot(slot); - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - - page = NULL; - } - - if (page && - page_count(page) - page_mapcount(page) != 1) { - if (scan < LAST_SCAN) - goto continue_resched; - + xas_set(&xas, 0); + xa_lock_irq(&mapping->pages); + xas_for_each_tag(&mapping->pages, &xas, page, ULONG_MAX, + SHMEM_TAG_PINNED) { + bool clear = true; + if (xa_is_value(page)) + continue; + if (page_count(page) - page_mapcount(page) != 1) { /* * On the last scan, we clean up all those tags * we inserted; but make a note that we still * found pages pinned. */ - error = -EBUSY; + if (scan == LAST_SCAN) + error = -EBUSY; + else + clear = false; } + if (clear) + xas_clear_tag(&mapping->pages, &xas, + SHMEM_TAG_PINNED); + if (++tagged % XA_CHECK_SCHED) + continue; - xa_lock_irq(&mapping->pages); - radix_tree_tag_clear(&mapping->pages, - iter.index, SHMEM_TAG_PINNED); + xas_pause(&xas); xa_unlock_irq(&mapping->pages); -continue_resched: - if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); - cond_resched_rcu(); - } + cond_resched(); + xa_lock_irq(&mapping->pages); } - rcu_read_unlock(); + xa_unlock_irq(&mapping->pages); } return error; -- 2.15.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>