From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id D3ADA6B0276 for ; Wed, 6 Apr 2016 17:29:40 -0400 (EDT) Received: by mail-pa0-f52.google.com with SMTP id bx7so24376132pad.3 for ; Wed, 06 Apr 2016 14:29:40 -0700 (PDT) Received: from mga04.intel.com (mga04.intel.com. [192.55.52.120]) by mx.google.com with ESMTP id o68si6894186pfj.173.2016.04.06.14.21.54 for ; Wed, 06 Apr 2016 14:21:54 -0700 (PDT) From: Matthew Wilcox Subject: [PATCH 17/30] radix-tree: Rewrite __radix_tree_lookup Date: Wed, 6 Apr 2016 17:21:26 -0400 Message-Id: <1459977699-2349-18-git-send-email-willy@linux.intel.com> In-Reply-To: <1459977699-2349-1-git-send-email-willy@linux.intel.com> References: <1459977699-2349-1-git-send-email-willy@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, Andrew Morton Cc: Matthew Wilcox , Ross Zwisler , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Konstantin Khlebnikov , Kirill Shutemov , Jan Kara , Neil Brown Use the new multi-order support functions to rewrite __radix_tree_lookup() Signed-off-by: Matthew Wilcox Reviewed-by: Ross Zwisler --- lib/radix-tree.c | 45 +++++++++++++++++---------------------------- 1 file changed, 17 insertions(+), 28 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 3dc52433a9cc..2ca2b416b476 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -634,44 +634,33 @@ void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, struct radix_tree_node **nodep, void ***slotp) { struct radix_tree_node *node, *parent; - unsigned int height, shift; + unsigned long maxindex; + unsigned int shift; void **slot; - node = rcu_dereference_raw(root->rnode); - if (node == NULL) + restart: + parent = NULL; + slot = (void **)&root->rnode; + shift = radix_tree_load_root(root, &node, &maxindex); + if (index > maxindex) return NULL; - if (!radix_tree_is_indirect_ptr(node)) { - if (index > 0) - return NULL; - - if (nodep) - *nodep = NULL; - if (slotp) - *slotp = (void **)&root->rnode; - return node; - } - node = indirect_to_ptr(node); - - height = node->path & RADIX_TREE_HEIGHT_MASK; - if (index > radix_tree_maxindex(height)) - return NULL; - - shift = (height-1) * RADIX_TREE_MAP_SHIFT; + for (;;) { + unsigned offset; - do { - parent = node; - slot = node->slots + ((index >> shift) & RADIX_TREE_MAP_MASK); - node = rcu_dereference_raw(*slot); - if (node == NULL) + if (!node) return NULL; + if (node == RADIX_TREE_RETRY) + goto restart; if (!radix_tree_is_indirect_ptr(node)) break; - node = indirect_to_ptr(node); + parent = indirect_to_ptr(node); shift -= RADIX_TREE_MAP_SHIFT; - height--; - } while (height > 0); + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + offset = radix_tree_descend(parent, &node, offset); + slot = parent->slots + offset; + } if (nodep) *nodep = parent; -- 2.8.0.rc3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org