From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36797) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vkthe-00042R-2I for qemu-devel@nongnu.org; Mon, 25 Nov 2013 05:47:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VkthV-0005vX-Ld for qemu-devel@nongnu.org; Mon, 25 Nov 2013 05:47:42 -0500 Received: from mx.ipv6.kamp.de ([2a02:248:0:51::16]:55367 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VkthV-0005tc-Ap for qemu-devel@nongnu.org; Mon, 25 Nov 2013 05:47:33 -0500 Message-ID: <52932ACF.6090104@kamp.de> Date: Mon, 25 Nov 2013 11:47:43 +0100 From: Peter Lieven MIME-Version: 1.0 References: <1380728469-29435-1-git-send-email-pl@kamp.de> <524C3FCE.4090908@redhat.com> <20131008123315.GE25109@dhcp-200-207.str.redhat.com> <5253FC11.3010309@redhat.com> <20131008123908.GG25109@dhcp-200-207.str.redhat.com> In-Reply-To: <20131008123908.GG25109@dhcp-200-207.str.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] block/iscsi: introduce bdrv_co_{readv, writev, flush_to_disk} List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , Paolo Bonzini Cc: ronniesahlberg@gmail.com, qemu-devel@nongnu.org, stefanha@redhat.com On 08.10.2013 14:39, Kevin Wolf wrote: > Am 08.10.2013 um 14:35 hat Paolo Bonzini geschrieben: >> Il 08/10/2013 14:33, Kevin Wolf ha scritto: >>>>>>> this converts read, write and flush functions from aio to coroutines. >>>>> I'm not sure it's already the time for this... Cancellation sucks in >>>>> QEMU, and this is going to make things even worse. >>> Not sure what you're referring to. If you mean iscsi_aio_cancel(), isn't >>> it dead code anyway since we changed block.c to use coroutines for >>> everything? bdrv_co_io_em() even throws the acb away, so even if you >>> wanted, there's no way to cancel the request even today. >> SCSI tries to use cancellation, and this results in VCPU threads >> starving all other threads. So I would like to introduce cancellation >> points for coroutines. > Sounds like a nice thing to have, but it's unrelated to this patch. > Cancellation means waiting for request completion before and after the > patch. > > Kevin Can we proceed with the above patch for 1.8? Peter