From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757553Ab0DFSxH (ORCPT ); Tue, 6 Apr 2010 14:53:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56962 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757084Ab0DFSw5 (ORCPT ); Tue, 6 Apr 2010 14:52:57 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20100406170903.GH5288@laptop> References: <20100406170903.GH5288@laptop> <23428.1270570789@redhat.com> To: Nick Piggin Cc: dhowells@redhat.com, paulmck@linux.vnet.ibm.com, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-cachefs@redhat.com Subject: Re: An incorrect assumption over radix_tree_tag_get() Date: Tue, 06 Apr 2010 19:52:45 +0100 Message-ID: <25610.1270579965@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nick Piggin wrote: > It is safe. Synchronization requirements for using the radix tree API > are documented. I presume you mean the big comment on it in radix-tree.h. According to that, it is not safe: * - any function _modifying_ the tree or tags (inserting or deleting * items, setting or clearing tags) must exclude other modifications, and * exclude any functions reading the tree. David