From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964916AbcBQBPW (ORCPT ); Tue, 16 Feb 2016 20:15:22 -0500 Received: from mail-pa0-f41.google.com ([209.85.220.41]:36316 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932904AbcBQBPU (ORCPT ); Tue, 16 Feb 2016 20:15:20 -0500 Message-ID: <56C3C9A4.1040109@gmail.com> Date: Tue, 16 Feb 2016 17:15:16 -0800 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Ioan Nicu , Ralf Baechle , Thomas Gleixner CC: David Daney , Aleksey Makarov , Leonid Rosenboim , Jiang Liu , Marc Zyngier , Alexander Sverdlin , Uwe Duerr , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] MIPS: Octeon: do not change affinity for disabled irqs References: <20160215154513.GF25050@ulegcpding.emea.nsn-net.net> In-Reply-To: <20160215154513.GF25050@ulegcpding.emea.nsn-net.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/15/2016 07:45 AM, Ioan Nicu wrote: > Octeon sets the default irq affinity to value 1 in the early arch init > code, so by default all irqs get registered with their affinity set to > core 0. > > When setting one CPU ofline, octeon_irq_cpu_offline_ciu() calls > irq_set_affinity_locked(), but this function sets the IRQD_AFFINITY_SET bit > in the irq descriptor. This has the side effect that if one irq is > requested later, after putting one CPU offline, the affinity of this irq > would not be the default anymore, but rather forced to "all cores - the > offline core". > > This patch sets the IRQCHIP_ONOFFLINE_ENABLED flag in octeon irq > controllers, so that the kernel would call the irq_cpu_[on|off]line() > callbacks only for enabled irqs. If some other irq is requested after > setting one cpu offline, it would use the default irq affinity, same as it > would do in the normal case where there is no CPU hotplug operation. > > Signed-off-by: Ioan Nicu > Acked-by: Alexander Sverdlin In principle, I don't object. I would like to see what tglx has to say about this though. If we are worried about the IRQD_AFFINITY_SET bit, I am not convinced that this is the best place to be tweaking code. Are we papering over something that should be handled in a more general manner? I don't know. David Daney > --- > arch/mips/cavium-octeon/octeon-irq.c | 15 ++++++++++++--- > 1 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c > index 368eb49..684582e 100644 > --- a/arch/mips/cavium-octeon/octeon-irq.c > +++ b/arch/mips/cavium-octeon/octeon-irq.c > @@ -935,6 +935,7 @@ static struct irq_chip octeon_irq_chip_ciu_v2 = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity_v2, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -948,6 +949,7 @@ static struct irq_chip octeon_irq_chip_ciu_v2_edge = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity_v2, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -963,6 +965,7 @@ static struct irq_chip octeon_irq_chip_ciu_sum2 = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity_sum2, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -976,6 +979,7 @@ static struct irq_chip octeon_irq_chip_ciu_sum2_edge = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity_sum2, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -988,6 +992,7 @@ static struct irq_chip octeon_irq_chip_ciu = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -1001,6 +1006,7 @@ static struct irq_chip octeon_irq_chip_ciu_edge = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -1041,7 +1047,7 @@ static struct irq_chip octeon_irq_chip_ciu_gpio_v2 = { > .irq_set_affinity = octeon_irq_ciu_set_affinity_v2, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > #endif > - .flags = IRQCHIP_SET_TYPE_MASKED, > + .flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_ONOFFLINE_ENABLED, > }; > > static struct irq_chip octeon_irq_chip_ciu_gpio = { > @@ -1056,7 +1062,7 @@ static struct irq_chip octeon_irq_chip_ciu_gpio = { > .irq_set_affinity = octeon_irq_ciu_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > #endif > - .flags = IRQCHIP_SET_TYPE_MASKED, > + .flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_ONOFFLINE_ENABLED, > }; > > /* > @@ -1838,6 +1844,7 @@ static struct irq_chip octeon_irq_chip_ciu2 = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu2_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -1851,6 +1858,7 @@ static struct irq_chip octeon_irq_chip_ciu2_edge = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu2_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > > @@ -1886,7 +1894,7 @@ static struct irq_chip octeon_irq_chip_ciu2_gpio = { > .irq_set_affinity = octeon_irq_ciu2_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > #endif > - .flags = IRQCHIP_SET_TYPE_MASKED, > + .flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_ONOFFLINE_ENABLED, > }; > > static int octeon_irq_ciu2_xlat(struct irq_domain *d, > @@ -2537,6 +2545,7 @@ static struct irq_chip octeon_irq_chip_ciu3 = { > #ifdef CONFIG_SMP > .irq_set_affinity = octeon_irq_ciu3_set_affinity, > .irq_cpu_offline = octeon_irq_cpu_offline_ciu, > + .flags = IRQCHIP_ONOFFLINE_ENABLED, > #endif > }; > >