From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f69.google.com (mail-pa0-f69.google.com [209.85.220.69]) by kanga.kvack.org (Postfix) with ESMTP id A1873828DF for ; Thu, 14 Apr 2016 10:18:30 -0400 (EDT) Received: by mail-pa0-f69.google.com with SMTP id vv3so93346619pab.2 for ; Thu, 14 Apr 2016 07:18:30 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id uk4si9817724pab.234.2016.04.14.07.18.29 for ; Thu, 14 Apr 2016 07:18:29 -0700 (PDT) From: Matthew Wilcox Subject: [PATCH v2 23/29] radix-tree: Rewrite radix_tree_tag_get Date: Thu, 14 Apr 2016 10:16:44 -0400 Message-Id: <1460643410-30196-24-git-send-email-willy@linux.intel.com> In-Reply-To: <1460643410-30196-1-git-send-email-willy@linux.intel.com> References: <1460643410-30196-1-git-send-email-willy@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, Andrew Morton Cc: Ross Zwisler , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Konstantin Khlebnikov , Kirill Shutemov , Jan Kara , Neil Brown , Matthew Wilcox From: Ross Zwisler Use the new multi-order support functions to rewrite radix_tree_tag_get() Signed-off-by: Ross Zwisler Signed-off-by: Matthew Wilcox --- lib/radix-tree.c | 44 ++++++++++++++++++-------------------------- 1 file changed, 18 insertions(+), 26 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index ee56562..b1ca744 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -831,45 +831,37 @@ EXPORT_SYMBOL(radix_tree_tag_clear); int radix_tree_tag_get(struct radix_tree_root *root, unsigned long index, unsigned int tag) { - unsigned int height, shift; - struct radix_tree_node *node; + struct radix_tree_node *node, *parent; + unsigned long maxindex; + unsigned int shift; - /* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; - node = rcu_dereference_raw(root->rnode); + shift = radix_tree_load_root(root, &node, &maxindex); + if (index > maxindex) + return 0; if (node == NULL) return 0; - if (!radix_tree_is_indirect_ptr(node)) - return (index == 0); - node = indirect_to_ptr(node); - - height = node->path & RADIX_TREE_HEIGHT_MASK; - if (index > radix_tree_maxindex(height)) - return 0; + while (radix_tree_is_indirect_ptr(node)) { + int offset; - shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + shift -= RADIX_TREE_MAP_SHIFT; + offset = (index >> shift) & RADIX_TREE_MAP_MASK; - for ( ; ; ) { - int offset; + parent = indirect_to_ptr(node); + offset = radix_tree_descend(parent, &node, offset); - if (node == NULL) + if (!node) return 0; - node = indirect_to_ptr(node); - - offset = (index >> shift) & RADIX_TREE_MAP_MASK; - if (!tag_get(node, tag, offset)) + if (!tag_get(parent, tag, offset)) return 0; - if (height == 1) - return 1; - node = rcu_dereference_raw(node->slots[offset]); - if (!radix_tree_is_indirect_ptr(node)) - return 1; - shift -= RADIX_TREE_MAP_SHIFT; - height--; + if (node == RADIX_TREE_RETRY) + break; } + + return 1; } EXPORT_SYMBOL(radix_tree_tag_get); -- 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