From 307c5971c972ef2bfd541d2850b36a692c6354c9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 29 Jun 2016 03:05:10 +0200 Subject: [PATCH] PM / hibernate: Recycle safe pages after image restoration One of the memory bitmaps used by the hibernation image restoration code is freed after the image has been loaded. That is not quite efficient, though, because the memory pages used for building that bitmap are known to be safe (ie. they were not used by the image kernel before hibernation) and the arch-specific code finalizing the image restoration may need them. In that case it needs to allocate those pages again via the memory management subsystem, check if they are really safe again by consulting the other bitmaps and so on. To avoid that, recycle those pages by putting them into the global list of known safe pages so that they can be given to the arch code right away when necessary. Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 40 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 39bbad5fac5a..94b6fe6c9ae3 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -158,6 +158,14 @@ static struct page *alloc_image_page(gfp_t gfp_mask) return page; } +static void recycle_safe_page(void *page_address) +{ + struct linked_page *lp = page_address; + + lp->next = safe_pages_list; + safe_pages_list = lp; +} + /** * free_image_page - free page represented by @addr, allocated with * get_image_page (page flags set by it must be cleared) @@ -852,6 +860,34 @@ struct nosave_region { static LIST_HEAD(nosave_regions); +static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone) +{ + struct rtree_node *node; + + list_for_each_entry(node, &zone->nodes, list) + recycle_safe_page(node->data); + + list_for_each_entry(node, &zone->leaves, list) + recycle_safe_page(node->data); +} + +static void memory_bm_recycle(struct memory_bitmap *bm) +{ + struct mem_zone_bm_rtree *zone; + struct linked_page *p_list; + + list_for_each_entry(zone, &bm->zones, list) + recycle_zone_bm_rtree(zone); + + p_list = bm->p_list; + while (p_list) { + struct linked_page *lp = p_list; + + p_list = lp->next; + recycle_safe_page(lp); + } +} + /** * register_nosave_region - register a range of page frames the contents * of which should not be saved during the suspend (to be used in the early @@ -2542,9 +2578,9 @@ void snapshot_write_finalize(struct snapshot_handle *handle) /* Restore page key for data page (s390 only). */ page_key_write(handle->buffer); page_key_free(); - /* Free only if we have loaded the image entirely */ + /* Do that only if we have loaded the image entirely */ if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) { - memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR); + memory_bm_recycle(&orig_bm); free_highmem_data(); } } -- 2.20.1