From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: question on freeze and aio Date: Tue, 13 Feb 2007 16:54:44 +0100 Message-ID: <200702131654.44748.rjw@sisk.pl> References: <1171056576.1484.41.camel@nigel.suspend2.net> <20070213101753.GC12996@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20070213101753.GC12996@elf.ucw.cz> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Tuesday, 13 February 2007 11:17, Pavel Machek wrote: > Hi! > = > > > > can there be running aio requests if all tasks are frozen? > > > = > > > Since tasks are frozen, no new aio requests would be submitted. We do= a > > > sync to ssek to complete existing requests; I haven't looked to see > > > whether that would need extending to flush aio as well, but don't thi= nk > > > that would be the case. Given everyone else's silence, so far, you mi= ght > > > be better to ask the author(s) of the aio code. > > = > > I believe Nigel is basically correct. However sync will only flush aio = > > for block devices. Other types of aio will remain active. > > = > > aio callbacks are interrupt-driven and execute in a workqueue (see > > fs/aio.c), and as far as I can tell that workqueue doesn't freeze. = > > Unless some general facility freezes all workqueues... > = > If this is so... we need to make that particular workqueue > freezeable. (And we should really make most workqueues freezeable). Except for the ones that are needed to save the image. Do we know which ones they are? Rafael