[PATCH v6 1/4] arm64, numa: adding numa support for arm64 platforms.
Ganapatrao Kulkarni
gpkulkarni at gmail.com
Sun Oct 25 22:45:07 PDT 2015
On Wed, Oct 21, 2015 at 2:24 PM, Ganapatrao Kulkarni
<gpkulkarni at gmail.com> wrote:
> On Tue, Oct 20, 2015 at 8:17 PM, Mark Rutland <mark.rutland at arm.com> wrote:
>> Hi,
>>
>> I'm away for the rest of this week and don't have the time to give this
>> a full review, but I've given this a first pass and have some high-level
>> comments:
>>
>> First, most of this is copy+paste from x86. We should try to share code
>> rather than duplicating it. Especially as it looks like there's cleanup
>> (and therefore divergence) that could happen.
> this is arch specific glue layer for numa.
> there might be some common functions and there will be arch specific
> hacks/exceptions.
> if we try to pull out common code then still will have some arch
> specific code or end up with unavoidable ifdefs.
> IMHO, this code better to be in arch (in single file).
>>
>> Second, this reimplements memblock to associate nids with memory
>> regions. I think we should keep memblock around for this (I'm under the
>> impression that Ard also wants that for memory attributes), rather than
>> creating a new memblock-like API that we then have to reconcile with
>> actual memblock information.
> thanks, this seems to be good idea to reuse the memblock code/infrastructures.
> will work on this.
this i have added and will be part of v7 patchset.
please review other changes.
>>
>> Third, NAK to the changes to /proc/cpuinfo, please drop that from the
>> patch. Further comments on that matter are inline below.
> ok.
>>
>> On Tue, Oct 20, 2015 at 04:15:28PM +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 | 63 +++++
>>> arch/arm64/kernel/setup.c | 9 +
>>> arch/arm64/kernel/smp.c | 2 +
>>> arch/arm64/mm/Makefile | 1 +
>>> arch/arm64/mm/init.c | 31 ++-
>>> arch/arm64/mm/numa.c | 531 ++++++++++++++++++++++++++++++++++++++++
>>> 8 files changed, 675 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 7d95663..0f9cdc7 100644
>>> --- a/arch/arm64/Kconfig
>>> +++ b/arch/arm64/Kconfig
>>> @@ -68,6 +68,7 @@ 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
>>> @@ -414,6 +415,30 @@ 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.
>>> +
>>> +config NODES_SHIFT
>>> + int "Maximum NUMA Nodes (as a power of 2)"
>>> + range 1 10
>>> + default "2"
>>> + depends on NEED_MULTIPLE_NODES
>>> + help
>>> + Specify the maximum number of NUMA Nodes available on the target
>>> + system. Increases memory reserved to accommodate various tables.
>>
>> How much memory do we end up requiring per node?
> not much. however it is proportional to number of max nodes supported
> by the system.
>>
>>> +
>>> +config USE_PERCPU_NUMA_NODE_ID
>>> + def_bool y
>>> + depends on NUMA
>>> +
>>> source kernel/Kconfig.preempt
>>>
>>> config HZ
>>> 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_
>>> +
>>> +#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)])
>>> +
>>> +#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..cadbd24
>>> --- /dev/null
>>> +++ b/arch/arm64/include/asm/numa.h
>>> @@ -0,0 +1,63 @@
>>> +#ifndef _ASM_NUMA_H
>>> +#define _ASM_NUMA_H
>>> +
>>> +#include <linux/nodemask.h>
>>> +#include <asm/topology.h>
>>> +
>>> +#ifdef CONFIG_NUMA
>>> +
>>> +#define NR_NODE_MEMBLKS (MAX_NUMNODES * 2)
>>> +#define ZONE_ALIGN (1UL << (MAX_ORDER + PAGE_SHIFT))
>>> +
>>> +/* 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
>>> +
>>> +struct __node_cpu_hwid {
>>> + int node_id; /* logical node containing this CPU */
>>> + u64 cpu_hwid; /* MPIDR for this CPU */
>>> +};
>>
>> We already have the MPIDR ID in the cpu_logical_map. Please don't
>> duplicate it here.
>>
>> As node_cpu_hwid seems to be indexed by logical ID, you can simlpy use
>> the same index for the logical map to get the MPIDR ID when necessary.
> thanks, this solves what we wanted to achieve with this mapping.
>>
>>> +
>>> +struct numa_memblk {
>>> + u64 start;
>>> + u64 end;
>>> + int nid;
>>> +};
>>> +
>>> +struct numa_meminfo {
>>> + int nr_blks;
>>> + struct numa_memblk blk[NR_NODE_MEMBLKS];
>>> +};
>>
>> I think we should keep the usual memblock around for this. It already
>> has some nid support.
> ok.
>>
>>> +
>>> +extern struct __node_cpu_hwid node_cpu_hwid[NR_CPUS];
>>> +extern nodemask_t numa_nodes_parsed __initdata;
>>> +
>>> +/* Mappings between node number and cpus on that node. */
>>> +extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
>>> +extern void numa_clear_node(unsigned int cpu);
>>> +#ifdef CONFIG_DEBUG_PER_CPU_MAPS
>>> +extern const struct cpumask *cpumask_of_node(int node);
>>> +#else
>>> +/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
>>> +static inline const struct cpumask *cpumask_of_node(int node)
>>> +{
>>> + return node_to_cpumask_map[node];
>>> +}
>>> +#endif
>>> +
>>> +void __init arm64_numa_init(void);
>>> +int __init numa_add_memblk(int nodeid, u64 start, u64 end);
>>> +void __init numa_set_distance(int from, int to, int distance);
>>> +void __init numa_reset_distance(void);
>>> +void numa_store_cpu_info(unsigned int cpu);
>>> +#else /* CONFIG_NUMA */
>>> +static inline void numa_store_cpu_info(unsigned int cpu) { }
>>> +static inline void arm64_numa_init(void) { }
>>> +#endif /* CONFIG_NUMA */
>>> +#endif /* _ASM_NUMA_H */
>>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
>>> index a2794da..4f3623d 100644
>>> --- a/arch/arm64/kernel/setup.c
>>> +++ b/arch/arm64/kernel/setup.c
>>> @@ -54,6 +54,7 @@
>>> #include <asm/elf.h>
>>> #include <asm/cpufeature.h>
>>> #include <asm/cpu_ops.h>
>>> +#include <asm/numa.h>
>>> #include <asm/sections.h>
>>> #include <asm/setup.h>
>>> #include <asm/smp_plat.h>
>>> @@ -485,6 +486,9 @@ static int __init topology_init(void)
>>> {
>>> int i;
>>>
>>> + for_each_online_node(i)
>>> + register_one_node(i);
>>> +
>>> for_each_possible_cpu(i) {
>>> struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
>>> cpu->hotpluggable = 1;
>>> @@ -557,7 +561,12 @@ static int c_show(struct seq_file *m, void *v)
>>> * online processors, looking for lines beginning with
>>> * "processor". Give glibc what it expects.
>>> */
>>> +#ifdef CONFIG_NUMA
>>> + seq_printf(m, "processor\t: %d", i);
>>> + seq_printf(m, " [nid: %d]\n", cpu_to_node(i));
>>> +#else
>>> seq_printf(m, "processor\t: %d\n", i);
>>> +#endif
>>
>> As above, NAK to a /proc/cpuinfo change.
>>
>> We don't have this on arch/arm and didn't previously have it on arm64,
>> so it could easily break existing software (both compat and native).
>> Having the format randomly change based on a config option is also not
>> great, and there's already been enough pain in this area.
>>
>> Additionally, other architctures don't have this, so it's clearly not
>> necessary.
> ok, will remove this.
>>
>> Surely there's a (portable/consistent) sysfs interface that provides the
>> NUMA information userspace requires? If not, we should add one that
>> works across architectures.
>>
>>>
>>> /*
>>> * Dump out the common processor features in a single line.
>>> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
>>> index dbdaacd..985ee04 100644
>>> --- a/arch/arm64/kernel/smp.c
>>> +++ b/arch/arm64/kernel/smp.c
>>> @@ -45,6 +45,7 @@
>>> #include <asm/cputype.h>
>>> #include <asm/cpu_ops.h>
>>> #include <asm/mmu_context.h>
>>> +#include <asm/numa.h>
>>> #include <asm/pgtable.h>
>>> #include <asm/pgalloc.h>
>>> #include <asm/processor.h>
>>> @@ -125,6 +126,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
>>> static void smp_store_cpu_info(unsigned int cpuid)
>>> {
>>> store_cpu_topology(cpuid);
>>> + numa_store_cpu_info(cpuid);
>>> }
>>>
>>> /*
>>> diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
>>> index 773d37a..bb92d41 100644
>>> --- a/arch/arm64/mm/Makefile
>>> +++ b/arch/arm64/mm/Makefile
>>> @@ -4,3 +4,4 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
>>> context.o proc.o pageattr.o
>>> obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
>>> obj-$(CONFIG_ARM64_PTDUMP) += dump.o
>>> +obj-$(CONFIG_NUMA) += numa.o
>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>>> index 697a6d0..81a0316 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 +78,20 @@ 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];
>>> +
>>> + memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
>>
>> You can make this simpler by initialising the variable when defining it:
>>
>> unsigned long max_zone_pfs[MAX_NR_ZONES] = { 0 };
> ok
>>
>>> + 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);
>>> +}
>>> +
>>> +#else
>>> static void __init zone_sizes_init(unsigned long min, unsigned long max)
>>> {
>>> struct memblock_region *reg;
>>> @@ -115,6 +130,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
>>>
>>> free_area_init_node(0, zone_size, min, zhole_size);
>>> }
>>> +#endif /* CONFIG_NUMA */
>>>
>>> #ifdef CONFIG_HAVE_ARCH_PFN_VALID
>>> int pfn_valid(unsigned long pfn)
>>> @@ -132,10 +148,15 @@ static void arm64_memory_present(void)
>>> static void arm64_memory_present(void)
>>> {
>>> struct memblock_region *reg;
>>> + int nid = 0;
>>>
>>> - for_each_memblock(memory, reg)
>>> - memory_present(0, memblock_region_memory_base_pfn(reg),
>>> - memblock_region_memory_end_pfn(reg));
>>> + for_each_memblock(memory, reg) {
>>> +#ifdef CONFIG_NUMA
>>> + nid = reg->nid;
>>> +#endif
>>> + memory_present(nid, memblock_region_memory_base_pfn(reg),
>>> + memblock_region_memory_end_pfn(reg));
>>> + }
>>> }
>>> #endif
>>>
>>> @@ -192,6 +213,9 @@ void __init bootmem_init(void)
>>>
>>> early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
>>>
>>> + max_pfn = max_low_pfn = max;
>>> +
>>> + arm64_numa_init();
>>> /*
>>> * Sparsemem tries to allocate bootmem in memory_present(), so must be
>>> * done after the fixed reservations.
>>> @@ -202,7 +226,6 @@ void __init bootmem_init(void)
>>> zone_sizes_init(min, max);
>>>
>>> high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
>>> - max_pfn = max_low_pfn = max;
>>> }
>>>
>>> #ifndef CONFIG_SPARSEMEM_VMEMMAP
>>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
>>> new file mode 100644
>>> index 0000000..4dd7436
>>> --- /dev/null
>>> +++ b/arch/arm64/mm/numa.c
>>> @@ -0,0 +1,531 @@
>>> +/*
>>> + * 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/kernel.h>
>>> +#include <linux/mm.h>
>>> +#include <linux/string.h>
>>> +#include <linux/init.h>
>>> +#include <linux/bootmem.h>
>>> +#include <linux/memblock.h>
>>> +#include <linux/ctype.h>
>>> +#include <linux/module.h>
>>> +#include <linux/nodemask.h>
>>> +#include <linux/sched.h>
>>> +#include <linux/topology.h>
>>> +#include <linux/mmzone.h>
>>
>> Nit: please sort these alphabetically.
> ok
>>
>>> +
>>> +#include <asm/smp_plat.h>
>>> +
>>> +struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
>>> +EXPORT_SYMBOL(node_data);
>>> +nodemask_t numa_nodes_parsed __initdata;
>>> +struct __node_cpu_hwid node_cpu_hwid[NR_CPUS];
>>> +
>>> +static int numa_off;
>>> +static int numa_distance_cnt;
>>> +static u8 *numa_distance;
>>> +static struct numa_meminfo numa_meminfo;
>>> +
>>> +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;
>>> + }
>>> + 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 (node >= nr_node_ids) {
>>> + pr_warn("cpumask_of_node(%d): node > nr_node_ids(%d)\n",
>>> + node, nr_node_ids);
>>> + dump_stack();
>>> + return cpu_none_mask;
>>> + }
>>
>> This can be:
>>
>> if (WARN_ON(node >= nr_node_ids))
>> return cpu_none_mask;
>>
> ok
>>> + if (node_to_cpumask_map[node] == NULL) {
>>> + pr_warn("cpumask_of_node(%d): no node_to_cpumask_map!\n",
>>> + node);
>>> + dump_stack();
>>> + return cpu_online_mask;
>>> + }
>>
>> Likewise:
>>
>> if (WARN_ON(!node_to_cpumask_map[node]))
>> return cpu_online_mask;
> ok.
>>
>>> + 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();
>>
>> Where would this be done otherwise?
> in function free_area_init_nodes
nr_node_ids is initialized to MAX_NUMANODE/node_possible_map.
setup_nr_node_ids is called to set to actual number of nodes.
>>
>> If we can initialise this earlier, what happens if we actually had
>> MAX_NUMNODES nodes?
> init of table for actual number of nodes, this is just to avoid
> uncesary table allocation.
>>
>>> +
>>> + /* allocate the map */
>>> + for (node = 0; node < nr_node_ids; node++)
>>> + alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
>>> +
>>> + /* Clear the mapping */
>>> + for (node = 0; node < nr_node_ids; node++)
>>> + cpumask_clear(node_to_cpumask_map[node]);
>>
>> Why not do these at the same time?
> ok, can be done.
>>
>> Can an allocation fail?
> most unlikely, however will add check.
>>
>>> +
>>> + 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 : node_cpu_hwid[cpu].node_id);
>>> +}
>>> +
>>> +/**
>>> + * numa_add_memblk_to - Add one numa_memblk to a numa_meminfo
>>> + */
>>> +
>>> +static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
>>> + struct numa_meminfo *mi)
>>> +{
>>> + /* ignore zero length blks */
>>> + if (start == end)
>>> + return 0;
>>> +
>>> + /* whine about and ignore invalid blks */
>>> + if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
>>> + pr_warn("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
>>> + nid, start, end - 1);
>>> + return 0;
>>> + }
>>
>> When would this happen?
> if acpi or dt binding is wrong/corrupt.
>>
>>> +
>>> + if (mi->nr_blks >= NR_NODE_MEMBLKS) {
>>> + pr_err("NUMA: too many memblk ranges\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + pr_info("NUMA: Adding memblock %d [0x%llx - 0x%llx] on node %d\n",
>>> + mi->nr_blks, start, end, nid);
>>> + mi->blk[mi->nr_blks].start = start;
>>> + mi->blk[mi->nr_blks].end = end;
>>> + mi->blk[mi->nr_blks].nid = nid;
>>> + mi->nr_blks++;
>>> + return 0;
>>> +}
>>
>> As I mentioned earlier, I think that we should keep the memblock
>> infrastructure around, and reuse it here.
> will try as said in the beginning.
>>
>>> +
>>> +/**
>>> + * numa_add_memblk - Add one numa_memblk to numa_meminfo
>>> + * @nid: NUMA node ID of the new memblk
>>> + * @start: Start address of the new memblk
>>> + * @end: End address of the new memblk
>>> + *
>>> + * Add a new memblk to the default numa_meminfo.
>>> + *
>>> + * RETURNS:
>>> + * 0 on success, -errno on failure.
>>> + */
>>> +#define MAX_PHYS_ADDR ((phys_addr_t)~0)
>>
>> We should probably rethink MAX_MEMBLOCK_ADDR and potentially make it
>> more generic so we can use it here and elsewhere. See commit
>> 8eafeb4802281651 ("of/fdt: make memblock maximum physical address arch
>> configurable").
>>
>> However, that might not matter if we're able to reuse memblock.
> ok
>>
>>> +
>>> +int __init numa_add_memblk(int nid, u64 base, u64 end)
>>> +{
>>> + const u64 phys_offset = __pa(PAGE_OFFSET);
>>> +
>>> + base &= PAGE_MASK;
>>> + end &= PAGE_MASK;
>>> +
>>> + if (base > MAX_PHYS_ADDR) {
>>> + pr_warn("NUMA: Ignoring memory block 0x%llx - 0x%llx\n",
>>> + base, base + end);
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + if (base + end > MAX_PHYS_ADDR) {
>>> + pr_info("NUMA: Ignoring memory range 0x%lx - 0x%llx\n",
>>> + ULONG_MAX, base + end);
>>> + end = MAX_PHYS_ADDR - base;
>>> + }
>>> +
>>> + if (base + end < phys_offset) {
>>> + pr_warn("NUMA: Ignoring memory block 0x%llx - 0x%llx\n",
>>> + base, base + end);
>>> + return -ENOMEM;
>>> + }
>>> + if (base < phys_offset) {
>>> + pr_info("NUMA: Ignoring memory range 0x%llx - 0x%llx\n",
>>> + base, phys_offset);
>>> + end -= phys_offset - base;
>>> + base = phys_offset;
>>> + }
>>> +
>>> + return numa_add_memblk_to(nid, base, base + end, &numa_meminfo);
>>> +}
>>> +EXPORT_SYMBOL(numa_add_memblk);
>>
>> I take it this is only used to look up the node for a given mermoy
>> region, rather than any region describe being usable by the kernel?
>> Otherwise that rounding of the base is worrying.
> yes this is to look up node for a memblock.
>>
>>> +
>>> +/* Initialize NODE_DATA for a node on the local memory */
>>> +static void __init setup_node_data(int nid, u64 start, u64 end)
>>> +{
>>> + const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
>>> + u64 nd_pa;
>>> + void *nd;
>>> + int tnid;
>>> +
>>> + start = roundup(start, ZONE_ALIGN);
>>> +
>>> + pr_info("Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
>>> + nid, start, end - 1);
>>> +
>>> + /*
>>> + * Allocate node data. Try node-local memory and then any node.
>>> + */
>>> + nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
>>
>> Why was nd_size rounded to PAGE_SIZE earlier if we only care about
> it is just aligned to pg_data_t too.
>> SMP_CACHE_BYTES alignment? I had assumed we wanted naturally-aligned
>> pages, but that doesn't seem to be the case given the above.
> what is the concern here?
>>
>>> + if (!nd_pa) {
>>> + nd_pa = __memblock_alloc_base(nd_size, SMP_CACHE_BYTES,
>>> + MEMBLOCK_ALLOC_ACCESSIBLE);
>>> + if (!nd_pa) {
>>> + pr_err("Cannot find %zu bytes in node %d\n",
>>> + nd_size, nid);
>>> + return;
>>> + }
>>> + }
>>> + nd = __va(nd_pa);
>>
>> Isn't memblock_alloc_try_nid sufficient for the above?
> thanks, will replace with memblock_alloc_try_nid.
>>
>>> +
>>> + /* 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 >> PAGE_SHIFT;
>>> + NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;
>>> +
>>> + node_set_online(nid);
>>> +}
>>> +
>>> +/*
>>> + * Set nodes, which have memory in @mi, in *@nodemask.
>>> + */
>>> +static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
>>> + const struct numa_meminfo *mi)
>>> +{
>>> + int i;
>>> +
>>> + for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
>>> + if (mi->blk[i].start != mi->blk[i].end &&
>>> + mi->blk[i].nid != NUMA_NO_NODE)
>>> + node_set(mi->blk[i].nid, *nodemask);
>>> +}
>>> +
>>> +/*
>>> + * Sanity check to catch more bad NUMA configurations (they are amazingly
>>> + * common). Make sure the nodes cover all memory.
>>> + */
>>
>> This comment is surprising, given this functionality is brand new.
> sorry. this is from x86, will remove it.
>>
>>> +static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
>>> +{
>>> + u64 numaram, totalram;
>>> + int i;
>>> +
>>> + numaram = 0;
>>> + for (i = 0; i < mi->nr_blks; i++) {
>>> + u64 s = mi->blk[i].start >> PAGE_SHIFT;
>>> + u64 e = mi->blk[i].end >> PAGE_SHIFT;
>>> +
>>> + numaram += e - s;
>>> + numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
>>> + if ((s64)numaram < 0)
>>> + numaram = 0;
>>> + }
>>> +
>>> + totalram = max_pfn - absent_pages_in_range(0, max_pfn);
>>> +
>>> + /* We seem to lose 3 pages somewhere. Allow 1M of slack. */
>>
>> We shouldn't rely on magic like this.
>>
>> Where and why are we "losing" pages, and why is that considered ok?
> need to experiment to know that is applicable still.
> will remove, if not relavant for us.
>>
>>> + if ((s64)(totalram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
>>> + pr_err("NUMA: nodes only cover %lluMB of your %lluMB Total RAM. Not used.\n",
>>> + (numaram << PAGE_SHIFT) >> 20,
>>> + (totalram << PAGE_SHIFT) >> 20);
>>> + return false;
>>> + }
>>> + return true;
>>> +}
>>> +
>>> +/**
>>> + * 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 = numa_distance_cnt * numa_distance_cnt *
>>> + sizeof(numa_distance[0]);
>>> +
>>> + /* numa_distance could be 1LU marking allocation failure, test cnt */
>>> + if (numa_distance_cnt)
>>> + memblock_free(__pa(numa_distance), size);
>>> + numa_distance_cnt = 0;
>>> + numa_distance = NULL; /* enable table creation */
>>> +}
>>> +
>>> +static int __init numa_alloc_distance(void)
>>> +{
>>> + nodemask_t nodes_parsed;
>>> + size_t size;
>>> + int i, j, cnt = 0;
>>> + u64 phys;
>>> +
>>> + /* size the new table and allocate it */
>>> + nodes_parsed = numa_nodes_parsed;
>>> + numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
>>> +
>>> + for_each_node_mask(i, nodes_parsed)
>>> + cnt = i;
>>> + cnt++;
>>> + size = cnt * cnt * sizeof(numa_distance[0]);
>>> +
>>> + phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
>>> + size, PAGE_SIZE);
>>> + if (!phys) {
>>> + pr_warn("NUMA: Warning: can't allocate distance table!\n");
>>> + /* don't retry until explicitly reset */
>>> + numa_distance = (void *)1LU;
>>
>> This doesn't look good. Why do we need to set this to a non-pointer
>> value?
> to avoid further attempts until unless table is reset.
>>
>> Thanks,
>> Mark.
>>
>>> + return -ENOMEM;
>>> + }
>>> + memblock_reserve(phys, size);
>>> +
>>> + numa_distance = __va(phys);
>>> + numa_distance_cnt = cnt;
>>> +
>>> + /* fill with the default distances */
>>> + for (i = 0; i < cnt; i++)
>>> + for (j = 0; j < cnt; j++)
>>> + numa_distance[i * cnt + j] = i == j ?
>>> + LOCAL_DISTANCE : REMOTE_DISTANCE;
>>> + pr_debug("NUMA: Initialized distance table, cnt=%d\n", 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 && numa_alloc_distance() < 0)
>>> + 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);
>>> +
>>> +static int __init numa_register_memblks(struct numa_meminfo *mi)
>>> +{
>>> + unsigned long uninitialized_var(pfn_align);
>>> + int i, nid;
>>> +
>>> + /* Account for nodes with cpus and no memory */
>>> + node_possible_map = numa_nodes_parsed;
>>> + numa_nodemask_from_meminfo(&node_possible_map, mi);
>>> + if (WARN_ON(nodes_empty(node_possible_map)))
>>> + return -EINVAL;
>>> +
>>> + for (i = 0; i < mi->nr_blks; i++) {
>>> + struct numa_memblk *mb = &mi->blk[i];
>>> +
>>> + memblock_set_node(mb->start, mb->end - mb->start,
>>> + &memblock.memory, mb->nid);
>>> + }
>>> +
>>> + /*
>>> + * If sections array is gonna be used for pfn -> nid mapping, check
>>> + * whether its granularity is fine enough.
>>> + */
>>> +#ifdef NODE_NOT_IN_PAGE_FLAGS
>>> + pfn_align = node_map_pfn_alignment();
>>> + if (pfn_align && pfn_align < PAGES_PER_SECTION) {
>>> + pr_warn("Node alignment %lluMB < min %lluMB, rejecting NUMA config\n",
>>> + PFN_PHYS(pfn_align) >> 20,
>>> + PFN_PHYS(PAGES_PER_SECTION) >> 20);
>>> + return -EINVAL;
>>> + }
>>> +#endif
>>> + if (!numa_meminfo_cover_memory(mi))
>>> + return -EINVAL;
>>> +
>>> + /* Finally register nodes. */
>>> + for_each_node_mask(nid, node_possible_map) {
>>> + u64 start = PFN_PHYS(max_pfn);
>>> + u64 end = 0;
>>> +
>>> + for (i = 0; i < mi->nr_blks; i++) {
>>> + if (nid != mi->blk[i].nid)
>>> + continue;
>>> + start = min(mi->blk[i].start, start);
>>> + end = max(mi->blk[i].end, end);
>>> + }
>>> +
>>> + if (start < end)
>>> + setup_node_data(nid, start, end);
>>> + }
>>> +
>>> + /* Dump memblock with node info and return. */
>>> + memblock_dump_all();
>>> + 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;
>>> +
>>> + ret = numa_register_memblks(&numa_meminfo);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + setup_node_to_cpumask_map();
>>> +
>>> + /* init boot processor */
>>> + 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.
>>> + */
>>> +static int __init dummy_numa_init(void)
>>> +{
>>> + pr_info("%s\n", "No NUMA configuration found");
>>> + pr_info("Faking a node at [mem %#018Lx-%#018Lx]\n",
>>> + 0LLU, PFN_PHYS(max_pfn) - 1);
>>> + node_set(0, numa_nodes_parsed);
>>> + numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
>>> + numa_off = 1;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * arm64_numa_init - Initialize NUMA
>>> + *
>>> + * Try each configured NUMA initialization method until one succeeds. The
>>> + * last fallback is dummy single node config encomapssing whole memory and
>>> + * never fails.
>>> + */
>>> +void __init arm64_numa_init(void)
>>> +{
>>> + numa_init(dummy_numa_init);
>>> +}
>>> --
>>> 1.8.1.4
>>>
> thanks
> Ganapat
thanks
Ganapat
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