From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35023) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dv01F-00059n-MB for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:51:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dv01A-0001zb-QU for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:51:49 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:50840) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dv01A-0001zC-JQ for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:51:44 -0400 Received: by mail-wm0-f44.google.com with SMTP id b195so1028019wmb.5 for ; Thu, 21 Sep 2017 04:51:44 -0700 (PDT) References: <20170921085110.25598-1-aik@ozlabs.ru> <20170921085110.25598-5-aik@ozlabs.ru> From: Paolo Bonzini Message-ID: Date: Thu, 21 Sep 2017 13:51:40 +0200 MIME-Version: 1.0 In-Reply-To: <20170921085110.25598-5-aik@ozlabs.ru> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH qemu v5 04/18] memory: Move AddressSpaceDispatch from AddressSpace to FlatView List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org On 21/09/2017 10:50, Alexey Kardashevskiy wrote: > * since FlatView::rcu is used now to dispose FV, call_rcu() in > address_space_update_topology() is replaced with direct call to > flatview_unref() Hmm, this is not correct, as you could have thread 1 thread 2 RCU thread ------------------------------------------------------------- rcu_read_lock read as->current_map set as->current_map flatview_unref '--> call_rcu flatview_ref rcu_read_unlock flatview_destroy I need to think a bit more about this (and possibly ask Paul...). Paolo