From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755438AbZCCSwu (ORCPT ); Tue, 3 Mar 2009 13:52:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753367AbZCCSwm (ORCPT ); Tue, 3 Mar 2009 13:52:42 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:58495 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341AbZCCSwl (ORCPT ); Tue, 3 Mar 2009 13:52:41 -0500 Date: Tue, 3 Mar 2009 19:52:25 +0100 From: Ingo Molnar To: Dimitri Sivanich Cc: Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , john stultz , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6 v6] SGI RTC: add generic system interrupt Message-ID: <20090303185225.GA5057@elte.hu> References: <20090303151044.GA20016@sgi.com> <20090303151357.GA20120@sgi.com> <20090303153433.GA29454@elte.hu> <20090303173943.GA30012@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090303173943.GA30012@sgi.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Dimitri Sivanich wrote: > On Tue, Mar 03, 2009 at 04:34:33PM +0100, Ingo Molnar wrote: > > > > * Dimitri Sivanich wrote: > > > > > This patch allocates a system interrupt vector for various > > > platform specific uses. > > > > this is really ugly. > > > > Also, why are all these symbols exported? There's no need to > > build the UV RTC driver as a module. It's either built-in or not > > built-in - it's small enough. > > OK. > > > > > this stuff: > > > > > +/* Function pointer for generic interrupt vector handling */ > > > +static void (*generic_interrupt_extension)(void); > > > +static char generic_show_string[28]; > > > +static char generic_show_prefix[6]; > > > + > > > +int is_generic_interrupt_registered() > > > +{ > > > + if (generic_interrupt_extension) > > > + return 1; > > > + else > > > + return 0; > > > +} > > > + > > > +char *generic_interrupt_string(void) > > > +{ > > > + return generic_show_string; > > > +} > > > + > > > +char *generic_interrupt_prefix(void) > > > +{ > > > + return generic_show_prefix; > > > +} > > > > is SMP unsafe, etc. etc. - not something we should ever call > > from a module. We just shouldnt do it in this form. What > > necessiates it? > > I wanted a way to show specific strings when displaying irq statistics. We could show these in a more generic way I suppose. > > Any given platform should just be changing these once, hence the lack of need for locking. > > > > > All we need is: > > > > > + /* generic IPI for platform specific use */ > > > + alloc_intr_gate(GENERIC_INTERRUPT_VECTOR, generic_interrupt); > > > > plus one trivial callback function - and then the UV platform > > uses it for its own purpose. It's not like two platforms will be > > running at once so there's no locking needed, etc. > > Right. But still register the callback function as I have it > now? i'd suggest to just override that global function pointer from the UV detection routines. this way we have it in a minimalistically generic fashion, but with a minimum amount of fuss around it. Ingo