On 2017年08月15日 17:49, Mel Gorman wrote:
> On Tue, Aug 15, 2017 at 04:45:35PM +0800, Kemi Wang wrote:
>> In this patch, NUMA statistics is separated from zone statistics
>> framework, all the call sites of NUMA stats are changed to use
>> numa-stats-specific functions, it does not have any functionality change
>> except that the value of NUMA stats is shown behind zone page stats, and
>> the threshold size of NUMA stats is shown behind pcp threshold when users
>> *read* the zone info.
>>
>> E.g. cat /proc/zoneinfo
>> ***Base*** ***With this patch***
>> nr_free_pages 3976 nr_free_pages 3976
>> nr_zone_inactive_anon 0 nr_zone_inactive_anon 0
>> nr_zone_active_anon 0 nr_zone_active_anon 0
>> nr_zone_inactive_file 0 nr_zone_inactive_file 0
>> nr_zone_active_file 0 nr_zone_active_file 0
>> nr_zone_unevictable 0 nr_zone_unevictable 0
>> nr_zone_write_pending 0 nr_zone_write_pending 0
>> nr_mlock 0 nr_mlock 0
>> nr_page_table_pages 0 nr_page_table_pages 0
>> nr_kernel_stack 0 nr_kernel_stack 0
>> nr_bounce 0 nr_bounce 0
>> nr_zspages 0 nr_zspages 0
>> numa_hit 0 *nr_free_cma 0*
>> numa_miss 0 numa_hit 0
>> numa_foreign 0 numa_miss 0
>> numa_interleave 0 numa_foreign 0
>> numa_local 0 numa_interleave 0
>> numa_other 0 numa_local 0
>> *nr_free_cma 0* numa_other 0
>> ... ...
>> vm stats threshold: 10 vm stats threshold: 10
>> ... *vm numa stats threshold: 10*
>> ...
>>
>> The next patch updates the numa stats counter size and threshold.
>>
>> Signed-off-by: Kemi Wang <kemi.w...@intel.com>
>> ---
>> drivers/base/node.c | 22 ++++---
>> include/linux/mmzone.h | 25 +++++---
>> include/linux/vmstat.h | 29 +++++++++
>> mm/page_alloc.c | 10 +--
>> mm/vmstat.c | 167
>> +++++++++++++++++++++++++++++++++++++++++++++++--
>> 5 files changed, 227 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/base/node.c b/drivers/base/node.c
>> index d8dc830..12080c6 100644
>> --- a/drivers/base/node.c
>> +++ b/drivers/base/node.c
>> @@ -160,12 +160,12 @@ static ssize_t node_read_numastat(struct device *dev,
>> "interleave_hit %lu\n"
>> "local_node %lu\n"
>> "other_node %lu\n",
>> - sum_zone_node_page_state(dev->id, NUMA_HIT),
>> - sum_zone_node_page_state(dev->id, NUMA_MISS),
>> - sum_zone_node_page_state(dev->id, NUMA_FOREIGN),
>> - sum_zone_node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
>> - sum_zone_node_page_state(dev->id, NUMA_LOCAL),
>> - sum_zone_node_page_state(dev->id, NUMA_OTHER));
>> + sum_zone_node_numa_state(dev->id, NUMA_HIT),
>> + sum_zone_node_numa_state(dev->id, NUMA_MISS),
>> + sum_zone_node_numa_state(dev->id, NUMA_FOREIGN),
>> + sum_zone_node_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
>> + sum_zone_node_numa_state(dev->id, NUMA_LOCAL),
>> + sum_zone_node_numa_state(dev->id, NUMA_OTHER));
>> }
>
> The names are very similar and it would be preferred if the names were
> visually different like sum_zone_numa_stat() which is hard to confuse with
> the zone stat fields.
>
Agree. Thanks for your suggestion.
>> static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
>>
>> @@ -181,9 +181,17 @@ static ssize_t node_read_vmstat(struct device *dev,
>> n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
>> sum_zone_node_page_state(nid, i));
>>
>> - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
>> +#ifdef CONFIG_NUMA
>> + for (i = 0; i < NR_VM_ZONE_NUMA_STAT_ITEMS; i++)
>> n += sprintf(buf+n, "%s %lu\n",
>> vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
>> + sum_zone_node_numa_state(nid, i));
>> +#endif
>
> Similar with NR_VM_ZONE_NUMA_STAT_ITEMS, it's too similar to
> NR_VM_NODE_STAT_ITEMS>
How about NR_VM_NUMA_STAT_ITEMS? anyone has better idea?
>> +
>> + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
>> + n += sprintf(buf+n, "%s %lu\n",
>> + vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
>> + NR_VM_ZONE_NUMA_STAT_ITEMS],
>> node_page_state(pgdat, i));
>>
>> return n;
>> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
>> index fc14b8b..0b11ba7 100644
>> --- a/include/linux/mmzone.h
>> +++ b/include/linux/mmzone.h
>> @@ -114,6 +114,20 @@ struct zone_padding {
>> #define ZONE_PADDING(name)
>> #endif
>>
>> +#ifdef CONFIG_NUMA
>> +enum zone_numa_stat_item {
>> + NUMA_HIT, /* allocated in intended node */
>> + NUMA_MISS, /* allocated in non intended node */
>> + NUMA_FOREIGN, /* was intended here, hit elsewhere */
>> + NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
>> + NUMA_LOCAL, /* allocation from local node */
>> + NUMA_OTHER, /* allocation from other node */
>> + NR_VM_ZONE_NUMA_STAT_ITEMS
>> +};
>> +#else
>> +#define NR_VM_ZONE_NUMA_STAT_ITEMS 0
>> +#endif
>> +
>> enum zone_stat_item {
>> /* First 128 byte cacheline (assuming 64 bit words) */
>> NR_FREE_PAGES,
>> @@ -132,14 +146,6 @@ enum zone_stat_item {
>> #if IS_ENABLED(CONFIG_ZSMALLOC)
>> NR_ZSPAGES, /* allocated in zsmalloc */
>> #endif
>> -#ifdef CONFIG_NUMA
>> - NUMA_HIT, /* allocated in intended node */
>> - NUMA_MISS, /* allocated in non intended node */
>> - NUMA_FOREIGN, /* was intended here, hit elsewhere */
>> - NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
>> - NUMA_LOCAL, /* allocation from local node */
>> - NUMA_OTHER, /* allocation from other node */
>> -#endif
>> NR_FREE_CMA_PAGES,
>> NR_VM_ZONE_STAT_ITEMS };
>>
>> @@ -276,6 +282,8 @@ struct per_cpu_pageset {
>> struct per_cpu_pages pcp;
>> #ifdef CONFIG_NUMA
>> s8 expire;
>> + s8 numa_stat_threshold;
>> + s8 vm_numa_stat_diff[NR_VM_ZONE_NUMA_STAT_ITEMS];
>> #endif
>> #ifdef CONFIG_SMP
>> s8 stat_threshold;
>
> Ok. this slightly increases the size of the per_cpu_pageset due to
> numa_stat_threshold. The structure occupes 2 cache lines and still occupies
> 2 cache lines afterwards so that is ok but consider hard-coding the value
> of it. The locality stats are never used as part of a decision made by the
> kernel and they get summed when reading proc unconditionally. There is little
> benefit to tuning that threshold at all and there should be a very small
> performance gain if it's removed because it'll be a compile-time constant.
>
Agree, Thanks. I will remove numa_stat_threshold in next version.
> The rest of the patch is mostly mechanical.
>
