From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41971) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S74sT-0004NN-8d for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:01:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S74sK-0000Ud-3N for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:01:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33716) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S74sJ-0000Tt-R8 for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:01:20 -0400 Message-ID: <4F5DF46F.9070006@redhat.com> Date: Mon, 12 Mar 2012 14:04:47 +0100 From: Kevin Wolf MIME-Version: 1.0 References: <1331226917-6658-1-git-send-email-pbonzini@redhat.com> <1331226917-6658-7-git-send-email-pbonzini@redhat.com> <4F5A31B2.3050701@redhat.com> <4F5A46A1.4000508@redhat.com> <1331402560.8577.46.camel@watermelon.coderich.net> <4F5DEBCE.3040409@redhat.com> In-Reply-To: <4F5DEBCE.3040409@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 06/17] block: use bdrv_{co, aio}_discard for write_zeroes operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Richard Laager , qemu-devel@nongnu.org Am 12.03.2012 13:27, schrieb Paolo Bonzini: > Il 10/03/2012 19:02, Richard Laager ha scritto: >> I propose adding the following behaviors in any event: >> * If a QEMU block device reports a discard_granularity > 0, it >> must be equal to 2^n (n >= 0), or QEMU's block core will change >> it to 0. (Non-power-of-two granularities are not likely to exist >> in the real world, and this assumption greatly simplifies >> ensuring correctness.) > > Yeah, I was considering this to be simply a bug in the block device. Block driver you mean? Yes, I think we can just assert() this. Kevin