From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LaEeK-0003ha-7x for qemu-devel@nongnu.org; Thu, 19 Feb 2009 14:33:32 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LaEeJ-0003fj-HC for qemu-devel@nongnu.org; Thu, 19 Feb 2009 14:33:31 -0500 Received: from [199.232.76.173] (port=59647 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LaEeJ-0003fZ-DG for qemu-devel@nongnu.org; Thu, 19 Feb 2009 14:33:31 -0500 Received: from mail2.shareable.org ([80.68.89.115]:33486) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LaEeI-000575-U2 for qemu-devel@nongnu.org; Thu, 19 Feb 2009 14:33:31 -0500 Received: from jamie by mail2.shareable.org with local (Exim 4.63) (envelope-from ) id 1LaEeC-0005pL-2j for qemu-devel@nongnu.org; Thu, 19 Feb 2009 19:33:24 +0000 Date: Thu, 19 Feb 2009 19:33:24 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] migration: adding migration to/from a file (v2) Message-ID: <20090219193324.GA22319@shareable.org> References: <499D4654.9000305@redhat.com> <499D652D.60803@codemonkey.ws> <499D8564.1070007@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <499D8564.1070007@redhat.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Uri Lublin wrote: > Your concern in the previous patch was that write() to a regular file might > block. That's why I'm calling select before calling write. Do you think > select will mark the fd as writeable but write would still block ? select() on a regular file _always_ marks the fd as writable. That's one of the rules of select(). For non-blocking file access you can only use threads or AIO, or a helper process. -- Jamie