Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751655AbdGZKDq (ORCPT ); Wed, 26 Jul 2017 06:03:46 -0400 Received: from mail-pf0-f176.google.com ([209.85.192.176]:34388 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751617AbdGZKDp (ORCPT ); Wed, 26 Jul 2017 06:03:45 -0400 Subject: Re: [PATCH v2] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES To: Marc Zyngier , Hanjun Guo , Thomas Gleixner Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, Ganapatrao Kulkarni , Lorenzo Pieralisi 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> <4e4c235c-c35c-10d8-8cb3-5a7ccad424b5@arm.com> From: Hanjun Guo Message-ID: <5db70933-807a-fba1-2f36-94c6b361c4cd@linaro.org> Date: Wed, 26 Jul 2017 18:03:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <4e4c235c-c35c-10d8-8cb3-5a7ccad424b5@arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4626 Lines: 117 On 2017/7/26 18:01, Marc Zyngier wrote: > 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. OK, thanks! Hanjun