Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751501AbdGZJsN (ORCPT ); Wed, 26 Jul 2017 05:48:13 -0400 Received: from mail-pg0-f48.google.com ([74.125.83.48]:38690 "EHLO mail-pg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421AbdGZJsL (ORCPT ); Wed, 26 Jul 2017 05:48:11 -0400 Subject: Re: [PATCH v2] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES To: John Garry , Hanjun Guo , Thomas Gleixner , Marc Zyngier Cc: Lorenzo Pieralisi , linux-kernel@vger.kernel.org, linuxarm@huawei.com, linux-acpi@vger.kernel.org, Ganapatrao Kulkarni , linux-arm-kernel@lists.infradead.org References: <1500695652-27025-1-git-send-email-guohanjun@huawei.com> From: Hanjun Guo Message-ID: Date: Wed, 26 Jul 2017 17:47:56 +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: 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: 2937 Lines: 80 On 2017/7/25 19:02, John Garry wrote: > On 22/07/2017 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; > > Question: Does !its_srat_maps always imply its_in_srat == 0, so we could > just fall through the for loop and return NUMA_NO_NODE without this check? > > Or should we be safe/explicit/or falling through loops is a bad coding > style? Hmm, you are right, I missed that point, its_in_srat will always be 0 if its_srat_maps be NULL, removed the NULL check and tested it on D03 (without ITS NUMA) and D03 boots OK, will remove the check in the new version. Thanks Hanjun