From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:45653) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDz2U-0004h0-1I for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:44:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TDz2T-0001Fg-27 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:44:37 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:41104) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDz2S-0001Fc-Sg for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:44:36 -0400 Received: by pbbrp12 with SMTP id rp12so138307pbb.4 for ; Tue, 18 Sep 2012 07:44:35 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <505888CC.8070207@redhat.com> Date: Tue, 18 Sep 2012 16:44:28 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1347968442-8860-1-git-send-email-kwolf@redhat.com> <1347968442-8860-16-git-send-email-kwolf@redhat.com> In-Reply-To: <1347968442-8860-16-git-send-email-kwolf@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 15/16] qcow2: Cancel COW when overwritten List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org Il 18/09/2012 13:40, Kevin Wolf ha scritto: > + qemu_co_mutex_unlock(&s->lock); > + qemu_co_rwlock_wrlock(&m->l2_writeback_lock); Can anybody else take the lock as reader again at this point? If not, I wonder if this is more clear if you write it as a CoQueue. Paolo > + has_wr_lock = true; > + qemu_co_mutex_lock(&s->lock);