From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1a7Isj-0007I4-2I for user-mode-linux-devel@lists.sourceforge.net; Fri, 11 Dec 2015 08:16:49 +0000 Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1a7Ish-0002i1-QN for user-mode-linux-devel@lists.sourceforge.net; Fri, 11 Dec 2015 08:16:49 +0000 References: <564F0C6D.8000806@kot-begemot.co.uk> <566A73FF.6080306@kot-begemot.co.uk> From: Richard Weinberger Message-ID: <566A8667.1040808@nod.at> Date: Fri, 11 Dec 2015 09:16:39 +0100 MIME-Version: 1.0 In-Reply-To: <566A73FF.6080306@kot-begemot.co.uk> List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net Subject: Re: [uml-devel] IRQ handler reentrancy To: Anton Ivanov Cc: "user-mode-linux-devel@lists.sourceforge.net" Am 11.12.2015 um 07:58 schrieb Anton Ivanov: >>> 2. I cannot catch what is wrong with the current code in signal.c. When >>> I read it, it should not produce re-entrancy. But it does. >> Sorry for the delay. Until now I did not find the time to dig into that. >> Did you find the offending code in signal.c? > > Yes. > > Unblock signals is logically incorrect - it will re-trigger an > interrupts even if there is an interrupt in flight whose processing has > not been finished. > > I tried several approaches both with the original poll() controller and > with my epoll() based version, some show promise. > > I had to put it aside until next Friday as I have some stuff due at work > so I cannot spare time to work on it until then. Once I get that out of > the way I should be able to spare it a day or two which should be enough > to finish it. > > Ditto for the UBD improvements. One thing we have to consider is that's legit to have SIGIO nested. I'm currently investigating whether we use do_IRQ() correctly. Thanks, //richard ------------------------------------------------------------------------------ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel