From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from az33egw01.freescale.net (az33egw01.freescale.net [192.88.158.102]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "az33egw01.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 522CADDF57 for ; Fri, 2 May 2008 02:14:57 +1000 (EST) Received: from az33smr01.freescale.net (az33smr01.freescale.net [10.64.34.199]) by az33egw01.freescale.net (8.12.11/az33egw01) with ESMTP id m41GEqtQ012665 for ; Thu, 1 May 2008 09:14:52 -0700 (MST) Received: from ld0162-tx32.am.freescale.net (ld0162-tx32.am.freescale.net [10.82.19.112]) by az33smr01.freescale.net (8.13.1/8.13.0) with ESMTP id m41GEp2X017057 for ; Thu, 1 May 2008 11:14:51 -0500 (CDT) Date: Thu, 1 May 2008 11:14:51 -0500 From: Scott Wood To: Kumar Gala Subject: Re: [PATCH] [POWERPC] Rework EXC_LEVEL_EXCEPTION_PROLOG code Message-ID: <20080501161451.GH17142@ld0162-tx32.am.freescale.net> References: <1209592495.18023.246.camel@pasglop> <12ECF63E-7CEA-48FD-9447-7D534C29271D@kernel.crashing.org> <18457.1279.401197.763726@cargo.ozlabs.ibm.com> <18457.32297.485053.356477@cargo.ozlabs.ibm.com> <2DF41779-732B-4477-9DAC-147CDC5C9885@kernel.crashing.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <2DF41779-732B-4477-9DAC-147CDC5C9885@kernel.crashing.org> Cc: linuxppc-dev@ozlabs.org, Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, May 01, 2008 at 08:17:07AM -0500, Kumar Gala wrote: > On May 1, 2008, at 3:24 AM, Paul Mackerras wrote: > >The most common cases are (a) something that ultimately generates > >input on a tty (e.g. a character arriving on a serial port) and that > >input turns out to be a ^C or similar, or (b) something that signals > >I/O completion and the program doing the I/O has requested > >notification by a SIGIO. But in general any driver code can send a > >signal to userspace if it wants. And, of course, SIGALRM and similar timer mechanisms. > ok. Was just wondering how the async exception know that the signal > it wanted to send belonged to the particular process that is running. > But I guess there are cases that the signal is really intended for who > ever is currently running? No, it knows based on its own data structures who it's intended for -- and sometimes that happens to be the currently running process. -Scott