Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751534AbdGZKBN (ORCPT ); Wed, 26 Jul 2017 06:01:13 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:58486 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750964AbdGZKBK (ORCPT ); Wed, 26 Jul 2017 06:01:10 -0400 Subject: Re: [PATCH v2] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES To: Hanjun Guo , Hanjun Guo , Thomas Gleixner References: <1500695652-27025-1-git-send-email-guohanjun@huawei.com> <91588872-441b-88c0-07e3-452c2998d173@arm.com> <998a03b4-89b1-7407-45ea-83a3128d66ed@arm.com> <3677255d-d8c9-0e01-df60-8c194397e384@linaro.org> Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, Ganapatrao Kulkarni , Lorenzo Pieralisi From: Marc Zyngier Organization: ARM Ltd Message-ID: <4e4c235c-c35c-10d8-8cb3-5a7ccad424b5@arm.com> Date: Wed, 26 Jul 2017 11:01:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <3677255d-d8c9-0e01-df60-8c194397e384@linaro.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4476 Lines: 116 On 26/07/17 10:55, Hanjun Guo wrote: > On 2017/7/26 16:00, Marc Zyngier wrote: >> On 26/07/17 08:52, Hanjun Guo wrote: >>> On 2017/7/25 18:30, Marc Zyngier wrote: >>>> On 22/07/17 04:54, Hanjun Guo wrote: >>>>> From: Hanjun Guo >>>>> >>>>> When running 4.13-rc1 on top of D05, I got the boot log: >>>>> >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1 >>>>> [ 0.000000] SRAT: ITS affinity exceeding max count[4] >>>>> >>>>> This is wrong on D05 as we have 8 ITSes with 4 NUMA nodes. >>>>> >>>>> So dynamically alloc the memory needed instead of using >>>>> its_srat_maps[MAX_NUMNODES], which count the number of >>>>> ITS entry(ies) in SRAT and alloc its_srat_maps as needed, >>>>> then build the mapping of numa node to ITS ID. Of course, >>>>> its_srat_maps will be freed after ITS probing because >>>>> we don't need that after boot. >>>>> >>>>> After doing this, I got what I wanted: >>>>> >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0 >>>>> [ 0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1 >>>>> [ 0.000000] SRAT: PXM 2 -> ITS 4 -> Node 2 >>>>> [ 0.000000] SRAT: PXM 2 -> ITS 5 -> Node 2 >>>>> [ 0.000000] SRAT: PXM 2 -> ITS 6 -> Node 2 >>>>> [ 0.000000] SRAT: PXM 3 -> ITS 7 -> Node 3 >>>>> >>>>> Fixes: dbd2b8267233 ("irqchip/gic-v3-its: Add ACPI NUMA node mapping") >>>>> Signed-off-by: Hanjun Guo >>>>> Cc: Ganapatrao Kulkarni >>>>> Cc: Lorenzo Pieralisi >>>>> Cc: Marc Zyngier >>>>> --- >>>>> >>>>> v1->v2: >>>>> - Add NULL check in acpi_get_its_numa_node() for no ITS affinity case; >>>>> - Free the its_srat_maps after ITS probing. >>>>> >>>>> drivers/irqchip/irq-gic-v3-its.c | 39 ++++++++++++++++++++++++++++++++------- >>>>> 1 file changed, 32 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c >>>>> index 3ccdf76..1d692aa 100644 >>>>> --- a/drivers/irqchip/irq-gic-v3-its.c >>>>> +++ b/drivers/irqchip/irq-gic-v3-its.c >>>>> @@ -1847,13 +1847,16 @@ struct its_srat_map { >>>>> u32 its_id; >>>>> }; >>>>> >>>>> -static struct its_srat_map its_srat_maps[MAX_NUMNODES] __initdata; >>>>> +static struct its_srat_map *its_srat_maps __initdata; >>>>> static int its_in_srat __initdata; >>>>> >>>>> static int __init acpi_get_its_numa_node(u32 its_id) >>>>> { >>>>> int i; >>>>> >>>>> + if (!its_srat_maps) >>>>> + return NUMA_NO_NODE; >>>>> + >>>>> for (i = 0; i < its_in_srat; i++) { >>>>> if (its_id == its_srat_maps[i].its_id) >>>>> return its_srat_maps[i].numa_node; >>>>> @@ -1861,6 +1864,12 @@ static int __init acpi_get_its_numa_node(u32 its_id) >>>>> return NUMA_NO_NODE; >>>>> } >>>>> >>>>> +static int __init gic_acpi_match_srat_its(struct acpi_subtable_header *header, >>>>> + const unsigned long end) >>>>> +{ >>>>> + return 0; >>>>> +} >>>>> + >>>>> static int __init gic_acpi_parse_srat_its(struct acpi_subtable_header *header, >>>>> const unsigned long end) >>>>> { >>>>> @@ -1877,12 +1886,6 @@ static int __init gic_acpi_parse_srat_its(struct acpi_subtable_header *header, >>>>> return -EINVAL; >>>>> } >>>>> >>>>> - if (its_in_srat >= MAX_NUMNODES) { >>>>> - pr_err("SRAT: ITS affinity exceeding max count[%d]\n", >>>>> - MAX_NUMNODES); >>>>> - return -EINVAL; >>>>> - } >>>>> - >>>> >>>> So you're getting rid of that message when overflowing the array... >>> >>> This overflowing will not happen, because I scan the SRAT >>> to count the entry(ies) of ITS affinity first to alloc the >>> array, and then parse the same SRAT again to setup the mapping >>> of NUMA node to ITS, so is it fine for us to just remove the >>> check here? >> >> Removing that check is fine, as long as you make sure the allocation >> hasn't failed. > > Sorry, just want to make sure I understand correctly. This function will > not be called if allocation failure, so do you mean we can keep the code > as it is? No. I mean adding this warning when the allocation fails, so that we know that our NUMA topology is screwed. M. -- Jazz is not dead. It just smells funny...