From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214AbdLFBBD (ORCPT ); Tue, 5 Dec 2017 20:01:03 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:46195 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753326AbdLFAmL (ORCPT ); Tue, 5 Dec 2017 19:42:11 -0500 From: Matthew Wilcox Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 30/73] mm: Convert workingset to XArray Date: Tue, 5 Dec 2017 16:41:16 -0800 Message-Id: <20171206004159.3755-31-willy@infradead.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20171206004159.3755-1-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox We construct a fake XA_STATE and use it to delete the node with xa_store() rather than adding a special function for this unique use case. Signed-off-by: Matthew Wilcox --- include/linux/swap.h | 4 ++-- mm/workingset.c | 48 ++++++++++++++++++++---------------------------- 2 files changed, 22 insertions(+), 30 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index c2b8128799c1..e4a8afcb214c 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -300,12 +300,12 @@ bool workingset_refault(void *shadow); void workingset_activation(struct page *page); /* Do not use directly, use workingset_lookup_update */ -void workingset_update_node(struct radix_tree_node *node); +void workingset_update_node(struct xa_node *node); /* Returns workingset_update_node() if the mapping has shadow entries. */ #define workingset_lookup_update(mapping) \ ({ \ - radix_tree_update_node_t __helper = workingset_update_node; \ + xa_update_node_t __helper = workingset_update_node; \ if (dax_mapping(mapping) || shmem_mapping(mapping)) \ __helper = NULL; \ __helper; \ diff --git a/mm/workingset.c b/mm/workingset.c index 0a3465700d5f..e51deb274d2f 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -148,7 +148,7 @@ * and activations is maintained (node->inactive_age). * * On eviction, a snapshot of this counter (along with some bits to - * identify the node) is stored in the now empty page cache radix tree + * identify the node) is stored in the now empty page cache * slot of the evicted page. This is called a shadow entry. * * On cache misses for which there are shadow entries, an eligible @@ -162,7 +162,7 @@ /* * Eviction timestamps need to be able to cover the full range of - * actionable refaults. However, bits are tight in the radix tree + * actionable refaults. However, bits are tight in the xarray * entry, and after storing the identifier for the lruvec there might * not be enough left to represent every single actionable refault. In * that case, we have to sacrifice granularity for distance, and group @@ -338,7 +338,7 @@ void workingset_activation(struct page *page) static struct list_lru shadow_nodes; -void workingset_update_node(struct radix_tree_node *node) +void workingset_update_node(struct xa_node *node) { /* * Track non-empty nodes that contain only shadow entries; @@ -370,7 +370,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, local_irq_enable(); /* - * Approximate a reasonable limit for the radix tree nodes + * Approximate a reasonable limit for the nodes * containing shadow entries. We don't need to keep more * shadow entries than possible pages on the active list, * since refault distances bigger than that are dismissed. @@ -385,11 +385,11 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, * worst-case density of 1/8th. Below that, not all eligible * refaults can be detected anymore. * - * On 64-bit with 7 radix_tree_nodes per page and 64 slots + * On 64-bit with 7 xa_nodes per page and 64 slots * each, this will reclaim shadow entries when they consume * ~1.8% of available memory: * - * PAGE_SIZE / radix_tree_nodes / node_entries * 8 / PAGE_SIZE + * PAGE_SIZE / xa_nodes / node_entries * 8 / PAGE_SIZE */ if (sc->memcg) { cache = mem_cgroup_node_nr_lru_pages(sc->memcg, sc->nid, @@ -410,9 +410,9 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg) { + XA_STATE(xas, NULL, 0); struct address_space *mapping; - struct radix_tree_node *node; - unsigned int i; + struct xa_node *node; int ret; /* @@ -420,14 +420,14 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, * the shadow node LRU under the mapping->pages.xa_lock and the * lru_lock. Because the page cache tree is emptied before * the inode can be destroyed, holding the lru_lock pins any - * address_space that has radix tree nodes on the LRU. + * address_space that has nodes on the LRU. * * We can then safely transition to the mapping->pages.xa_lock to * pin only the address_space of the particular node we want * to reclaim, take the node off-LRU, and drop the lru_lock. */ - node = container_of(item, struct radix_tree_node, private_list); + node = container_of(item, struct xa_node, private_list); mapping = container_of(node->root, struct address_space, pages); /* Coming from the list, invert the lock order */ @@ -449,25 +449,17 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, goto out_invalid; if (WARN_ON_ONCE(node->count != node->exceptional)) goto out_invalid; - for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { - if (node->slots[i]) { - if (WARN_ON_ONCE(!xa_is_value(node->slots[i]))) - goto out_invalid; - if (WARN_ON_ONCE(!node->exceptional)) - goto out_invalid; - if (WARN_ON_ONCE(!mapping->nrexceptional)) - goto out_invalid; - node->slots[i] = NULL; - node->exceptional--; - node->count--; - mapping->nrexceptional--; - } - } - if (WARN_ON_ONCE(node->exceptional)) - goto out_invalid; + mapping->nrexceptional -= node->exceptional; + xas.xa = node->root; + xas.xa_node = node->parent; + xas.xa_offset = node->offset; + xas.xa_update = workingset_update_node; + /* + * We could store a shadow entry here which was the minimum of the + * shadow entries we were tracking ... + */ + xas_store(&xas, NULL); inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM); - __radix_tree_delete_node(&mapping->pages, node, - workingset_lookup_update(mapping)); out_invalid: xa_unlock(&mapping->pages); -- 2.15.0