From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <50349F8D.3080102@xenomai.org> Date: Wed, 22 Aug 2012 10:59:57 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Can we have nested interrupt handling in Xenomai? List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: ali hagigat Cc: Xenomai@xenomai.org On 08/22/2012 06:28 AM, ali hagigat wrote: > Can we have nested interrupt handling in Xenomai? Suppose we are in > the middle of an interrupt handler and a new interrupt comes in, CPU > will start executing the handler of the new interrupt completely? or > that interrupt is logged only for that domain to be serviced later? No, we do not support nested interrupt. You should note that the Linux kernel has stopped re-enabling hardware interrupts in the middle of the interrupt handlers for some time now: if an interrupt handler takes a long time to execute, then there is a bug in the interrupt handler. The interrupt handler has to be fixed, re-enabling interrupts is a bad workaround. > > As far as I understood, when an interrupt comes, that interrupt is > disabled and the domain pipeline is stalled and then the interrupt > handler is called. > When the interrupt handler returns, the domain pipeline is unstalled. > Is that correct? Not quite, it depends on which domain is current and which domain the interrupt is for. -- Gilles.