From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422758AbWJFRKN (ORCPT ); Fri, 6 Oct 2006 13:10:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422754AbWJFRKM (ORCPT ); Fri, 6 Oct 2006 13:10:12 -0400 Received: from nf-out-0910.google.com ([64.233.182.191]:34037 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S1422758AbWJFRKL (ORCPT ); Fri, 6 Oct 2006 13:10:11 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=PmO4jC0u35UxIDOZO9V4qAqMe4HYkp7ZvdojoYDwRo6tPwIebGKjFBydla7T2QolCEIfISbhJoZ7blJF84ntk8ZGnILhZGoHVswZKTADOllu+nV5TmfVLiM9ml622WYHL45YFv+IPg4xuymkG+ZgoECrfOdrpE/ZdlJViorp8oA= Message-ID: <513a5e60610061010k2fb0b8cex245f009d8d79de69@mail.gmail.com> Date: Fri, 6 Oct 2006 12:10:09 -0500 From: "Madhu Saravana Sibi Govindan" To: "Jan Engelhardt" Subject: Re: Using "Asynchronous Notifications" within an interrupt handler Cc: linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <513a5e60610051727t7f7c7b78u62410c4b8f8502a7@mail.gmail.com> <513a5e60610051753o1dd828c4i52b8ba563601694a@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the information. I have another quick question: my device driver can expect up to 4 different interrupts (from 4 hardware devices). Can I send a posix real-time signal (SIGRTMIN) using the kill_async interface and expect the kernel to queue these signals for delievery to the sleeping process? (Because if I use SIGIO it is possible that an incoming interrupt is lost because the kernel doesn't queue up normal signals, right?). Thanks, G.Sibi On 10/6/06, Jan Engelhardt wrote: > > > > My question is: is it safe to use the asynchronous notification > > mechanism within an interrupt handler? I see that this call acquires a > > bunch of locks before sending the signal to the process. Would this > > cause any deadlocking situations? Or should I resort to the top and > > bottom half approach for interrupt handling and handle the > > notification in the bottom half? > > It may be possible - I have an old driver for custom hardware lying > around here, and it does this in the irq handler: > > kill_fasync(&global.fasync_ptr, SIGIO, POLL_IN); > > > > -`J' > -- >