From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 3/11] powerpc: convert to generic helpers for IPI function calls Date: Tue, 22 Apr 2008 14:13:16 +0200 Message-ID: <20080422121315.GE12774@kernel.dk> References: <1208851058-8500-1-git-send-email-jens.axboe@oracle.com> <1208851058-8500-4-git-send-email-jens.axboe@oracle.com> <18445.54284.194023.553595@cargo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <18445.54284.194023.553595-UYQwCShxghk5kJ7NmlRacFaTQe2KTcn/@public.gmane.org> Sender: linux-arch-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: To: Paul Mackerras Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, npiggin-l3A5Bk7waGM@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, anton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org On Tue, Apr 22 2008, Paul Mackerras wrote: > Jens Axboe writes: > > > This converts ppc to use the new helpers for smp_call_function() and > > friends, and adds support for smp_call_function_single(). > > Looks OK, and runs on a dual G5 powermac here. I'll try on some > bigger IBM boxes tomorrow, or maybe Anton can do that. Thanks a lot, Paul! > I notice that you have changed the semantics slightly in that > previously, the powerpc implementation would wait for the other cpus > to have taken the interrupt, and print a message if they didn't all > take the interrupt (this was different from the function of the `wait' > parameter, which said whether to wait for all cpus to finish executing > the specified function). > > Now the generic smp_call_function_mask doesn't wait for the other cpus > to take the interrupt. I don't think that's likely to be a problem, > but I do think that's worth mentioning in the patch description. > > It's probably also worth mentioning that smp_send_stop no longer has > the behaviour of doing its stuff even if someone is holding the lock, > but that is OK (presumably) because now the lock (call_function_lock > in the new code) is held for much shorter periods and there doesn't > appear to be much danger of other cpus getting stuck or panicking > while holding that lock. I touched on both of these points in the initial mail, but perhaps you missed it as I didn't CC everyone for the 0/11 part. I'll add the full explanation to the 1/11 patch as well. > You can put Acked-by: Paul Mackerras on the ppc > patch, but please extend the description a bit as outlined above. I'll add the ack, let me know if you still think I should do more on the changelog side. -- Jens Axboe From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from brick.kernel.dk ([87.55.233.238]:2163 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbYDVMNV (ORCPT ); Tue, 22 Apr 2008 08:13:21 -0400 Date: Tue, 22 Apr 2008 14:13:16 +0200 From: Jens Axboe Subject: Re: [PATCH 3/11] powerpc: convert to generic helpers for IPI function calls Message-ID: <20080422121315.GE12774@kernel.dk> References: <1208851058-8500-1-git-send-email-jens.axboe@oracle.com> <1208851058-8500-4-git-send-email-jens.axboe@oracle.com> <18445.54284.194023.553595@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18445.54284.194023.553595@cargo.ozlabs.ibm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Paul Mackerras Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, npiggin@suse.de, torvalds@linux-foundation.org, anton@samba.org Message-ID: <20080422121316.p5yjBC8pMUkMlW7u43-UhwbKBzyOsXqRMXve4icJpPg@z> On Tue, Apr 22 2008, Paul Mackerras wrote: > Jens Axboe writes: > > > This converts ppc to use the new helpers for smp_call_function() and > > friends, and adds support for smp_call_function_single(). > > Looks OK, and runs on a dual G5 powermac here. I'll try on some > bigger IBM boxes tomorrow, or maybe Anton can do that. Thanks a lot, Paul! > I notice that you have changed the semantics slightly in that > previously, the powerpc implementation would wait for the other cpus > to have taken the interrupt, and print a message if they didn't all > take the interrupt (this was different from the function of the `wait' > parameter, which said whether to wait for all cpus to finish executing > the specified function). > > Now the generic smp_call_function_mask doesn't wait for the other cpus > to take the interrupt. I don't think that's likely to be a problem, > but I do think that's worth mentioning in the patch description. > > It's probably also worth mentioning that smp_send_stop no longer has > the behaviour of doing its stuff even if someone is holding the lock, > but that is OK (presumably) because now the lock (call_function_lock > in the new code) is held for much shorter periods and there doesn't > appear to be much danger of other cpus getting stuck or panicking > while holding that lock. I touched on both of these points in the initial mail, but perhaps you missed it as I didn't CC everyone for the 0/11 part. I'll add the full explanation to the 1/11 patch as well. > You can put Acked-by: Paul Mackerras on the ppc > patch, but please extend the description a bit as outlined above. I'll add the ack, let me know if you still think I should do more on the changelog side. -- Jens Axboe