From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50520) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUGX7-0002qt-Lk for qemu-devel@nongnu.org; Fri, 12 Feb 2016 11:25:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aUGX2-0008D9-NP for qemu-devel@nongnu.org; Fri, 12 Feb 2016 11:25:25 -0500 Received: from mx2.parallels.com ([199.115.105.18]:52384) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUGX2-0008D1-HE for qemu-devel@nongnu.org; Fri, 12 Feb 2016 11:25:20 -0500 References: <1455259174-3384-1-git-send-email-den@openvz.org> <1455259174-3384-3-git-send-email-den@openvz.org> <20160212125035.GA4920@work-vm> <56BDD62C.5030605@redhat.com> From: "Denis V. Lunev" Message-ID: <56BE0764.7080401@openvz.org> Date: Fri, 12 Feb 2016 19:25:08 +0300 MIME-Version: 1.0 In-Reply-To: <56BDD62C.5030605@redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] migration: move bdrv_invalidate_cache_all of of coroutine context List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , "Dr. David Alan Gilbert" Cc: Amit Shah , qemu-devel@nongnu.org, Juan Quintela On 02/12/2016 03:55 PM, Paolo Bonzini wrote: > > On 12/02/2016 13:50, Dr. David Alan Gilbert wrote: >> I'll admit to not really understanding what the difference is >> between bh and coroutine context; I'd thought if it was all >> in the main thread stuff was safe. > It's arguably a bug in the block layer code. It assumes that all code > called from a coroutine wants not to block. Moving stuff to a bottom > half tells the block layer that you want bdrv_invalidate_cache_all to block. > > Paolo cool description! Really short and exhaustive!