From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id E454F8E004D for ; Tue, 11 Dec 2018 03:06:12 -0500 (EST) Received: by mail-ed1-f70.google.com with SMTP id c3so6667864eda.3 for ; Tue, 11 Dec 2018 00:06:12 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id i26-v6sor3478822ejz.40.2018.12.11.00.06.10 for (Google Transport Security); Tue, 11 Dec 2018 00:06:11 -0800 (PST) MIME-Version: 1.0 References: <20181206121152.GH1286@dhcp22.suse.cz> <20181207075322.GS1286@dhcp22.suse.cz> <20181207113044.GB1286@dhcp22.suse.cz> <20181207142240.GC1286@dhcp22.suse.cz> <20181207155627.GG1286@dhcp22.suse.cz> <20181210123738.GN1286@dhcp22.suse.cz> In-Reply-To: <20181210123738.GN1286@dhcp22.suse.cz> From: Pingfan Liu Date: Tue, 11 Dec 2018 16:05:58 +0800 Message-ID: Subject: Re: [PATCH] mm/alloc: fallback to first node if the wanted node offline Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org Cc: Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Mike Rapoport , Bjorn Helgaas , Jonathan Cameron On Mon, Dec 10, 2018 at 8:37 PM Michal Hocko wrote: > > On Fri 07-12-18 16:56:27, Michal Hocko wrote: > > On Fri 07-12-18 22:27:13, Pingfan Liu wrote: > > [...] > > > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > > > index 1308f54..4dc497d 100644 > > > --- a/arch/x86/mm/numa.c > > > +++ b/arch/x86/mm/numa.c > > > @@ -754,18 +754,23 @@ void __init init_cpu_to_node(void) > > > { > > > int cpu; > > > u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid); > > > + int node, nr; > > > > > > BUG_ON(cpu_to_apicid == NULL); > > > + nr = cpumask_weight(cpu_possible_mask); > > > + > > > + /* bring up all possible node, since dev->numa_node */ > > > + //should check acpi works for node possible, > > > + for_each_node(node) > > > + if (!node_online(node)) > > > + init_memory_less_node(node); > > > > I suspect there is no change if you replace for_each_node by > > for_each_node_mask(nid, node_possible_map) > > > > here. If that is the case then we are probably calling > > free_area_init_node too early. I do not see it yet though. > > OK, so it is not about calling it late or soon. It is just that > node_possible_map is a misnomer and it has a different semantic than > I've expected. numa_nodemask_from_meminfo simply considers only nodes > with some memory. So my patch didn't really make any difference and the > node stayed uninialized. > > In other words. Does the following work? I am sorry to wildguess this > way but I am not able to recreate your setups to play with this myself. > No problem. Yeah, in order to debug the patch, you need a numa machine with a memory-less node. And unlucky, the patch can not work either by grub bootup or kexec -l boot. There is nothing, just silent. I will dig into numa_register_memblks() to figure out the problem. Thanks, Pingfan > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > index 1308f5408bf7..d51643e10d00 100644 > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -216,8 +216,6 @@ static void __init alloc_node_data(int nid) > > node_data[nid] = nd; > memset(NODE_DATA(nid), 0, sizeof(pg_data_t)); > - > - node_set_online(nid); > } > > /** > @@ -527,6 +525,19 @@ static void __init numa_clear_kernel_node_hotplug(void) > } > } > > +static void __init init_memory_less_node(int nid) > +{ > + unsigned long zones_size[MAX_NR_ZONES] = {0}; > + unsigned long zholes_size[MAX_NR_ZONES] = {0}; > + > + free_area_init_node(nid, zones_size, 0, zholes_size); > + > + /* > + * All zonelists will be built later in start_kernel() after per cpu > + * areas are initialized. > + */ > +} > + > static int __init numa_register_memblks(struct numa_meminfo *mi) > { > unsigned long uninitialized_var(pfn_align); > @@ -570,7 +581,7 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) > return -EINVAL; > > /* Finally register nodes. */ > - for_each_node_mask(nid, node_possible_map) { > + for_each_node(nid) { > u64 start = PFN_PHYS(max_pfn); > u64 end = 0; > > @@ -592,6 +603,10 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) > continue; > > alloc_node_data(nid); > + if (!end) > + init_memory_less_node(nid); > + else > + node_set_online(nid); > } > > /* Dump memblock with node info and return. */ > @@ -721,21 +736,6 @@ void __init x86_numa_init(void) > numa_init(dummy_numa_init); > } > > -static void __init init_memory_less_node(int nid) > -{ > - unsigned long zones_size[MAX_NR_ZONES] = {0}; > - unsigned long zholes_size[MAX_NR_ZONES] = {0}; > - > - /* Allocate and initialize node data. Memory-less node is now online.*/ > - alloc_node_data(nid); > - free_area_init_node(nid, zones_size, 0, zholes_size); > - > - /* > - * All zonelists will be built later in start_kernel() after per cpu > - * areas are initialized. > - */ > -} > - > /* > * Setup early cpu_to_node. > * > @@ -763,9 +763,6 @@ void __init init_cpu_to_node(void) > if (node == NUMA_NO_NODE) > continue; > > - if (!node_online(node)) > - init_memory_less_node(node); > - > numa_set_node(cpu, node); > } > } > -- > Michal Hocko > SUSE Labs