[PATCH v7 1/4] arm64, numa: adding numa support for arm64 platforms.
Ganapatrao Kulkarni
gpkulkarni at gmail.com
Tue Dec 22 01:34:48 PST 2015
Hi Will,
On Fri, Dec 18, 2015 at 12:00 AM, Ganapatrao Kulkarni
<gpkulkarni at gmail.com> wrote:
> Thanks Will for the review.
>
> On Thu, Dec 17, 2015 at 10:41 PM, Will Deacon <will.deacon at arm.com> wrote:
>> Hello,
>>
>> This all looks pretty reasonable, but I'd like to see an Ack from a
>> devicetree maintainer on the binding before I merge anything (and I see
>> that there are outstanding comments from Rutland on that).
> IIUC, there are no open comments for the binding.
> Mark Rutland: please let me know, if there any open comments.
> otherwise, can you please Ack the binding.
>>
>> On Tue, Nov 17, 2015 at 10:50:40PM +0530, Ganapatrao Kulkarni wrote:
>>> Adding numa support for arm64 based platforms.
>>> This patch adds by default the dummy numa node and
>>> maps all memory and cpus to node 0.
>>> using this patch, numa can be simulated on single node arm64 platforms.
>>>
>>> Reviewed-by: Robert Richter <rrichter at cavium.com>
>>> Signed-off-by: Ganapatrao Kulkarni <gkulkarni at caviumnetworks.com>
>>> ---
>>> arch/arm64/Kconfig | 25 +++
>>> arch/arm64/include/asm/mmzone.h | 17 ++
>>> arch/arm64/include/asm/numa.h | 47 +++++
>>> arch/arm64/kernel/setup.c | 4 +
>>> arch/arm64/kernel/smp.c | 2 +
>>> arch/arm64/mm/Makefile | 1 +
>>> arch/arm64/mm/init.c | 30 +++-
>>> arch/arm64/mm/numa.c | 384 ++++++++++++++++++++++++++++++++++++++++
>>> 8 files changed, 506 insertions(+), 4 deletions(-)
>>> create mode 100644 arch/arm64/include/asm/mmzone.h
>>> create mode 100644 arch/arm64/include/asm/numa.h
>>> create mode 100644 arch/arm64/mm/numa.c
>>>
>>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>>> index 9ac16a4..7d8fb42 100644
>>> --- a/arch/arm64/Kconfig
>>> +++ b/arch/arm64/Kconfig
>>> @@ -71,6 +71,7 @@ config ARM64
>>> select HAVE_GENERIC_DMA_COHERENT
>>> select HAVE_HW_BREAKPOINT if PERF_EVENTS
>>> select HAVE_MEMBLOCK
>>> + select HAVE_MEMBLOCK_NODE_MAP if NUMA
>>> select HAVE_PATA_PLATFORM
>>> select HAVE_PERF_EVENTS
>>> select HAVE_PERF_REGS
>>> @@ -482,6 +483,30 @@ config HOTPLUG_CPU
>>> Say Y here to experiment with turning CPUs off and on. CPUs
>>> can be controlled through /sys/devices/system/cpu.
>>>
>>> +# Common NUMA Features
>>> +config NUMA
>>> + bool "Numa Memory Allocation and Scheduler Support"
>>> + depends on SMP
>>> + help
>>> + Enable NUMA (Non Uniform Memory Access) support.
>>> +
>>> + The kernel will try to allocate memory used by a CPU on the
>>> + local memory controller of the CPU and add some more
>>> + NUMA awareness to the kernel.
>>
>> I appreciate that this is copied from x86, but what exactly do you mean
>> by "memory controller" here?
> ok, it is fair enough to say local memory.
>>
>>> diff --git a/arch/arm64/include/asm/mmzone.h b/arch/arm64/include/asm/mmzone.h
>>> new file mode 100644
>>> index 0000000..6ddd468
>>> --- /dev/null
>>> +++ b/arch/arm64/include/asm/mmzone.h
>>> @@ -0,0 +1,17 @@
>>> +#ifndef __ASM_ARM64_MMZONE_H_
>>> +#define __ASM_ARM64_MMZONE_H_
>>
>> Please try to follow the standard naming for header guards under arm64
>> (yes, it's not perfect, but we've made some effort for consistency).
> sure, will follow as in other code.
>>
>>> +
>>> +#ifdef CONFIG_NUMA
>>> +
>>> +#include <linux/mmdebug.h>
>>> +#include <linux/types.h>
>>> +
>>> +#include <asm/smp.h>
>>> +#include <asm/numa.h>
>>> +
>>> +extern struct pglist_data *node_data[];
>>> +
>>> +#define NODE_DATA(nid) (node_data[(nid)])
>>
>> This is the same as m32r, metag, parisc, powerpc, s390, sh, sparc, tile
>> and x86. Can we make this the default in the core code instead and then
>> replace this header file with asm-generic or something?
> IIUC, it is same in most but not in all arch.
>>
>>> +
>>> +#endif /* CONFIG_NUMA */
>>> +#endif /* __ASM_ARM64_MMZONE_H_ */
>>> diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
>>> new file mode 100644
>>> index 0000000..c00f3a4
>>> --- /dev/null
>>> +++ b/arch/arm64/include/asm/numa.h
>>> @@ -0,0 +1,47 @@
>>> +#ifndef _ASM_NUMA_H
>>> +#define _ASM_NUMA_H
>>
>> Same comment on the guards.
> ok
>>
>>> +#include <linux/nodemask.h>
>>> +#include <asm/topology.h>
>>> +
>>> +#ifdef CONFIG_NUMA
>>> +
>>> +#define NR_NODE_MEMBLKS (MAX_NUMNODES * 2)
>>
>> This is only used by the ACPI code afaict, so maybe include it when you
>> add that?
> ok
>>
>>> +#define ZONE_ALIGN (1UL << (MAX_ORDER + PAGE_SHIFT))
>>
>> Where is this used?
> sorry, was used in v6, missed to delete.
>>
>>> +
>>> +/* currently, arm64 implements flat NUMA topology */
>>> +#define parent_node(node) (node)
>>> +
>>> +extern int __node_distance(int from, int to);
>>> +#define node_distance(a, b) __node_distance(a, b)
>>> +
>>> +/* dummy definitions for pci functions */
>>> +#define pcibus_to_node(node) 0
>>> +#define cpumask_of_pcibus(bus) 0
>>
>> There's a bunch of these dummy definitions already available in
>> asm-generic/topology.h. Can we use those instead of rolling our own
>> please?
these are dummy in this patch, and i will post separate patch for numa-pci.
>>
>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>>> index 17bf39a..8dc9c5d 100644
>>> --- a/arch/arm64/mm/init.c
>>> +++ b/arch/arm64/mm/init.c
>>> @@ -37,6 +37,7 @@
>>>
>>> #include <asm/fixmap.h>
>>> #include <asm/memory.h>
>>> +#include <asm/numa.h>
>>> #include <asm/sections.h>
>>> #include <asm/setup.h>
>>> #include <asm/sizes.h>
>>> @@ -77,6 +78,19 @@ static phys_addr_t max_zone_dma_phys(void)
>>> return min(offset + (1ULL << 32), memblock_end_of_DRAM());
>>> }
>>>
>>> +#ifdef CONFIG_NUMA
>>> +static void __init zone_sizes_init(unsigned long min, unsigned long max)
>>> +{
>>> + unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
>>> +
>>> + if (IS_ENABLED(CONFIG_ZONE_DMA))
>>> + max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
>>> + max_zone_pfns[ZONE_NORMAL] = max;
>>> +
>>> + free_area_init_nodes(max_zone_pfns);
>>> +}
>>
>> This is certainly more readable then the non-numa zone_sizes_init. Is
>> there a reason we can't always select HAVE_MEMBLOCK_NODE_MAP and avoid
>> having to handle the zone holds explicitly?
> yes, i can think off to have select HAVE_MEMBLOCK_NODE_MAP always
> instead of for only numa.
> i can experiment to have the zone_sizes_init of numa to non-numa case
> also and delete the current zone_sizes_init.
if i enable HAVE_MEMBLOCK_NODE_MAP for non-numa case, i see issues in
sparse_init and could be some dependency due to explicit call of
memory_present(note sure) in non-numa.
IMO, this needs to be worked out as a separate patch.
>
>>
>> Also, I couldn't find any calls to memblock_add_node, which seem to be
>> expected. What am I missing?
> memblks are added much before numa in dt or acpi parsing.
> memblock_set_node is used to set the node.
>>
>>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
>>> new file mode 100644
>>> index 0000000..e3afbf8
>>> --- /dev/null
>>> +++ b/arch/arm64/mm/numa.c
>>> @@ -0,0 +1,384 @@
>>> +/*
>>> + * NUMA support, based on the x86 implementation.
>>> + *
>>> + * Copyright (C) 2015 Cavium Inc.
>>> + * Author: Ganapatrao Kulkarni <gkulkarni at cavium.com>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#include <linux/bootmem.h>
>>> +#include <linux/ctype.h>
>>> +#include <linux/init.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/mm.h>
>>> +#include <linux/memblock.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mmzone.h>
>>> +#include <linux/nodemask.h>
>>> +#include <linux/sched.h>
>>> +#include <linux/string.h>
>>> +#include <linux/topology.h>
>>> +
>>> +#include <asm/smp_plat.h>
>>> +
>>> +struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
>>> +EXPORT_SYMBOL(node_data);
>>> +nodemask_t numa_nodes_parsed __initdata;
>>> +int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
>>> +
>>> +static int numa_off;
>>> +static int numa_distance_cnt;
>>> +static u8 *numa_distance;
>>> +
>>> +static __init int numa_parse_early_param(char *opt)
>>> +{
>>> + if (!opt)
>>> + return -EINVAL;
>>> + if (!strncmp(opt, "off", 3)) {
>>> + pr_info("%s\n", "NUMA turned off");
>>> + numa_off = 1;
>>
>> There's a patch kicking around to add this to strtobool:
> will change once it is in upstream. dont want to have dependency for this.
>>
>> https://lkml.org/lkml/2015/12/9/802
>>
>> but I can't see it in next :(
>>
>>> + }
>>> + return 0;
>>> +}
>>> +early_param("numa", numa_parse_early_param);
>>> +
>>> +cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
>>> +EXPORT_SYMBOL(node_to_cpumask_map);
>>> +
>>> +#ifdef CONFIG_DEBUG_PER_CPU_MAPS
>>> +/*
>>> + * Returns a pointer to the bitmask of CPUs on Node 'node'.
>>> + */
>>> +const struct cpumask *cpumask_of_node(int node)
>>> +{
>>> +
>>> + if (WARN_ON(node >= nr_node_ids))
>>> + return cpu_none_mask;
>>> +
>>> + if (WARN_ON(node_to_cpumask_map[node] == NULL))
>>> + return cpu_online_mask;
>>> +
>>> + return node_to_cpumask_map[node];
>>> +}
>>> +EXPORT_SYMBOL(cpumask_of_node);
>>> +#endif
>>> +
>>> +static void map_cpu_to_node(unsigned int cpu, int nid)
>>> +{
>>> + set_cpu_numa_node(cpu, nid);
>>> + if (nid >= 0)
>>> + cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
>>> +}
>>> +
>>> +static void unmap_cpu_to_node(unsigned int cpu)
>>> +{
>>> + int nid = cpu_to_node(cpu);
>>> +
>>> + if (nid >= 0)
>>> + cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
>>> + set_cpu_numa_node(cpu, NUMA_NO_NODE);
>>> +}
>>> +
>>> +void numa_clear_node(unsigned int cpu)
>>> +{
>>> + unmap_cpu_to_node(cpu);
>>> +}
>>> +
>>> +/*
>>> + * Allocate node_to_cpumask_map based on number of available nodes
>>> + * Requires node_possible_map to be valid.
>>> + *
>>> + * Note: cpumask_of_node() is not valid until after this is done.
>>> + * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
>>> + */
>>> +static void __init setup_node_to_cpumask_map(void)
>>> +{
>>> + unsigned int cpu;
>>> + int node;
>>> +
>>> + /* setup nr_node_ids if not done yet */
>>> + if (nr_node_ids == MAX_NUMNODES)
>>> + setup_nr_node_ids();
>>> +
>>> + /* allocate and clear the mapping */
>>> + for (node = 0; node < nr_node_ids; node++) {
>>> + alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
>>> + cpumask_clear(node_to_cpumask_map[node]);
>>> + }
>>> +
>>> + for_each_possible_cpu(cpu)
>>> + set_cpu_numa_node(cpu, NUMA_NO_NODE);
>>> +
>>> + /* cpumask_of_node() will now work */
>>> + pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
>>> +}
>>> +
>>> +/*
>>> + * Set the cpu to node and mem mapping
>>> + */
>>> +void numa_store_cpu_info(unsigned int cpu)
>>> +{
>>> + map_cpu_to_node(cpu, numa_off ? 0 : cpu_to_node_map[cpu]);
>>> +}
>>> +
>>> +/**
>>> + * numa_add_memblk - Set node id to memblk
>>> + * @nid: NUMA node ID of the new memblk
>>> + * @start: Start address of the new memblk
>>> + * @size: Size of the new memblk
>>> + *
>>> + * RETURNS:
>>> + * 0 on success, -errno on failure.
>>> + */
>>> +int __init numa_add_memblk(int nid, u64 start, u64 size)
>>> +{
>>> + int ret;
>>> +
>>> + ret = memblock_set_node(start, size, &memblock.memory, nid);
>>> + if (ret < 0) {
>>> + pr_err("NUMA: memblock [0x%llx - 0x%llx] failed to add on node %d\n",
>>> + start, (start + size - 1), nid);
>>> + return ret;
>>> + }
>>> +
>>> + node_set(nid, numa_nodes_parsed);
>>> + pr_info("NUMA: Adding memblock [0x%llx - 0x%llx] on node %d\n",
>>> + start, (start + size - 1), nid);
>>> + return ret;
>>> +}
>>> +EXPORT_SYMBOL(numa_add_memblk);
>>> +
>>> +/* Initialize NODE_DATA for a node on the local memory */
>>> +static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
>>> +{
>>> + const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
>>> + u64 nd_pa;
>>> + void *nd;
>>> + int tnid;
>>> +
>>> + pr_info("Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
>>> + nid, start_pfn << PAGE_SHIFT,
>>> + (end_pfn << PAGE_SHIFT) - 1);
>>> +
>>> + nd_pa = memblock_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
>>> + nd = __va(nd_pa);
>>> +
>>> + /* report and initialize */
>>> + pr_info(" NODE_DATA [mem %#010Lx-%#010Lx]\n",
>>> + nd_pa, nd_pa + nd_size - 1);
>>> + tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
>>> + if (tnid != nid)
>>> + pr_info(" NODE_DATA(%d) on node %d\n", nid, tnid);
>>> +
>>> + node_data[nid] = nd;
>>> + memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
>>> + NODE_DATA(nid)->node_id = nid;
>>> + NODE_DATA(nid)->node_start_pfn = start_pfn;
>>> + NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
>>> +}
>>> +
>>> +/**
>>> + * numa_reset_distance - Reset NUMA distance table
>>> + *
>>> + * The current table is freed.
>>> + * The next numa_set_distance() call will create a new one.
>>> + */
>>> +void __init numa_reset_distance(void)
>>> +{
>>> + size_t size;
>>> +
>>> + if (!numa_distance)
>>> + return;
>>> +
>>> + size = numa_distance_cnt * numa_distance_cnt *
>>> + sizeof(numa_distance[0]);
>>> +
>>> + memblock_free(__pa(numa_distance), size);
>>> + numa_distance_cnt = 0;
>>> + numa_distance = NULL;
>>> +}
>>> +
>>> +static int __init numa_alloc_distance(void)
>>> +{
>>> + size_t size;
>>> + u64 phys;
>>> + int i, j;
>>> +
>>> + size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
>>> + phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
>>> + size, PAGE_SIZE);
>>> + if (WARN_ON(!phys))
>>> + return -ENOMEM;
>>> +
>>> + memblock_reserve(phys, size);
>>> +
>>> + numa_distance = __va(phys);
>>> + numa_distance_cnt = nr_node_ids;
>>> +
>>> + /* fill with the default distances */
>>> + for (i = 0; i < numa_distance_cnt; i++)
>>> + for (j = 0; j < numa_distance_cnt; j++)
>>> + numa_distance[i * numa_distance_cnt + j] = i == j ?
>>> + LOCAL_DISTANCE : REMOTE_DISTANCE;
>>> +
>>> + pr_debug("NUMA: Initialized distance table, cnt=%d\n",
>>> + numa_distance_cnt);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * numa_set_distance - Set NUMA distance from one NUMA to another
>>> + * @from: the 'from' node to set distance
>>> + * @to: the 'to' node to set distance
>>> + * @distance: NUMA distance
>>> + *
>>> + * Set the distance from node @from to @to to @distance. If distance table
>>> + * doesn't exist, one which is large enough to accommodate all the currently
>>> + * known nodes will be created.
>>> + *
>>> + * If such table cannot be allocated, a warning is printed and further
>>> + * calls are ignored until the distance table is reset with
>>> + * numa_reset_distance().
>>> + *
>>> + * If @from or @to is higher than the highest known node or lower than zero
>>> + * at the time of table creation or @distance doesn't make sense, the call
>>> + * is ignored.
>>> + * This is to allow simplification of specific NUMA config implementations.
>>> + */
>>> +void __init numa_set_distance(int from, int to, int distance)
>>> +{
>>> + if (!numa_distance)
>>> + return;
>>> +
>>> + if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
>>> + from < 0 || to < 0) {
>>> + pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
>>> + from, to, distance);
>>> + return;
>>> + }
>>> +
>>> + if ((u8)distance != distance ||
>>> + (from == to && distance != LOCAL_DISTANCE)) {
>>> + pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
>>> + from, to, distance);
>>> + return;
>>> + }
>>> +
>>> + numa_distance[from * numa_distance_cnt + to] = distance;
>>> +}
>>> +EXPORT_SYMBOL(numa_set_distance);
>>> +
>>> +int __node_distance(int from, int to)
>>> +{
>>> + if (from >= numa_distance_cnt || to >= numa_distance_cnt)
>>> + return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
>>> + return numa_distance[from * numa_distance_cnt + to];
>>> +}
>>> +EXPORT_SYMBOL(__node_distance);
>>
>> Much of this is simply a direct copy/paste from x86. Why can't it be
>> moved to common code? I don't see anything arch-specific here.
> not same for all arch.
>>
>>> +static int __init numa_register_nodes(void)
>>> +{
>>> + int nid;
>>> + struct memblock_region *mblk;
>>> +
>>> + /* Check that valid nid is set to memblks */
>>> + for_each_memblock(memory, mblk)
>>> + if (mblk->nid == NUMA_NO_NODE || mblk->nid >= MAX_NUMNODES)
>>> + return -EINVAL;
>>> +
>>> + /* Finally register nodes. */
>>> + for_each_node_mask(nid, numa_nodes_parsed) {
>>> + unsigned long start_pfn, end_pfn;
>>> +
>>> + get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
>>> + setup_node_data(nid, start_pfn, end_pfn);
>>> + node_set_online(nid);
>>> + }
>>> +
>>> + /* Setup online nodes to actual nodes*/
>>> + node_possible_map = numa_nodes_parsed;
>>> +
>>> + /* Dump memblock with node info and return. */
>>> + memblock_dump_all();
>>
>> We already call this from arm64_memblock_init. If that's now too early
>> to be of any use, we should move it to after bootmem_init, but we should
>> probably avoid calling it twice.
> sure, will do changes to have called once.
>>
>>> + return 0;
>>> +}
>>> +
>>> +static int __init numa_init(int (*init_func)(void))
>>> +{
>>> + int ret;
>>> +
>>> + nodes_clear(numa_nodes_parsed);
>>> + nodes_clear(node_possible_map);
>>> + nodes_clear(node_online_map);
>>> + numa_reset_distance();
>>> +
>>> + ret = init_func();
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + if (nodes_empty(numa_nodes_parsed))
>>> + return -EINVAL;
>>> +
>>> + ret = numa_register_nodes();
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + ret = numa_alloc_distance();
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + setup_node_to_cpumask_map();
>>> +
>>> + /* init boot processor */
>>> + cpu_to_node_map[0] = 0;
>>> + map_cpu_to_node(0, 0);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * dummy_numa_init - Fallback dummy NUMA init
>>> + *
>>> + * Used if there's no underlying NUMA architecture, NUMA initialization
>>> + * fails, or NUMA is disabled on the command line.
>>> + *
>>> + * Must online at least one node and add memory blocks that cover all
>>> + * allowed memory. This function must not fail.
>>
>> Why can't it fail? It looks like the return value is ignored by numa_init.
> this function adds all memblocks to node 0. which is unlikely that it will fail.
>
>
>>
>> Will
> thanks
> Ganapat
thanks
Ganapat
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