From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59725) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUDFk-0002tj-UD for qemu-devel@nongnu.org; Fri, 12 Feb 2016 07:55:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aUDFg-00076V-Tg for qemu-devel@nongnu.org; Fri, 12 Feb 2016 07:55:16 -0500 Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]:33968) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aUDFg-00076R-Mb for qemu-devel@nongnu.org; Fri, 12 Feb 2016 07:55:12 -0500 Received: by mail-wm0-x241.google.com with SMTP id p63so2539537wmp.1 for ; Fri, 12 Feb 2016 04:55:12 -0800 (PST) Sender: Paolo Bonzini References: <1455259174-3384-1-git-send-email-den@openvz.org> <1455259174-3384-3-git-send-email-den@openvz.org> <20160212125035.GA4920@work-vm> From: Paolo Bonzini Message-ID: <56BDD62C.5030605@redhat.com> Date: Fri, 12 Feb 2016 13:55:08 +0100 MIME-Version: 1.0 In-Reply-To: <20160212125035.GA4920@work-vm> Content-Type: text/plain; charset=windows-1252 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: "Dr. David Alan Gilbert" , "Denis V. Lunev" Cc: Amit Shah , qemu-devel@nongnu.org, Juan Quintela 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