From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: question on freeze and aio Date: Tue, 13 Feb 2007 11:17:53 +0100 Message-ID: <20070213101753.GC12996@elf.ucw.cz> References: <1171056576.1484.41.camel@nigel.suspend2.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: 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: Alan Stern Cc: linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org 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 think > > that would be the case. Given everyone else's silence, so far, you might > > 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). Pavel -- = (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html