From: Shakeel Butt Date: Fri, 26 Aug 2022 23:06:42 +0000 (+0000) Subject: mm: deduplicate cacheline padding code X-Git-Tag: v6.6.17~6355^2~314 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e6ad640bc404eb298dd1880113131768ddf5c6a8;p=platform%2Fkernel%2Flinux-rpi.git mm: deduplicate cacheline padding code There are three users (mmzone.h, memcontrol.h, page_counter.h) using similar code for forcing cacheline padding between fields of different structures. Dedup that code. Link: https://lkml.kernel.org/r/20220826230642.566725-1-shakeelb@google.com Signed-off-by: Shakeel Butt Suggested-by: Feng Tang Reviewed-by: Feng Tang Acked-by: Michal Hocko Signed-off-by: Andrew Morton --- diff --git a/include/linux/cache.h b/include/linux/cache.h index d742c57..5da1bbd 100644 --- a/include/linux/cache.h +++ b/include/linux/cache.h @@ -85,4 +85,17 @@ #define cache_line_size() L1_CACHE_BYTES #endif +/* + * Helper to add padding within a struct to ensure data fall into separate + * cachelines. + */ +#if defined(CONFIG_SMP) +struct cacheline_padding { + char x[0]; +} ____cacheline_internodealigned_in_smp; +#define CACHELINE_PADDING(name) struct cacheline_padding name +#else +#define CACHELINE_PADDING(name) +#endif + #endif /* __LINUX_CACHE_H */ diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 344022f10..60545e4 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -185,15 +185,6 @@ struct mem_cgroup_thresholds { struct mem_cgroup_threshold_ary *spare; }; -#if defined(CONFIG_SMP) -struct memcg_padding { - char x[0]; -} ____cacheline_internodealigned_in_smp; -#define MEMCG_PADDING(name) struct memcg_padding name -#else -#define MEMCG_PADDING(name) -#endif - /* * Remember four most recent foreign writebacks with dirty pages in this * cgroup. Inode sharing is expected to be uncommon and, even if we miss @@ -304,7 +295,7 @@ struct mem_cgroup { spinlock_t move_lock; unsigned long move_lock_flags; - MEMCG_PADDING(_pad1_); + CACHELINE_PADDING(_pad1_); /* memory.stat */ struct memcg_vmstats vmstats; @@ -326,7 +317,7 @@ struct mem_cgroup { struct list_head objcg_list; #endif - MEMCG_PADDING(_pad2_); + CACHELINE_PADDING(_pad2_); /* * set > 0 if pages under this cgroup are moving to other cgroup. diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index e335a49..c69c081 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -121,20 +121,6 @@ static inline bool free_area_empty(struct free_area *area, int migratetype) struct pglist_data; -/* - * Add a wild amount of padding here to ensure data fall into separate - * cachelines. There are very few zone structures in the machine, so space - * consumption is not a concern here. - */ -#if defined(CONFIG_SMP) -struct zone_padding { - char x[0]; -} ____cacheline_internodealigned_in_smp; -#define ZONE_PADDING(name) struct zone_padding name; -#else -#define ZONE_PADDING(name) -#endif - #ifdef CONFIG_NUMA enum numa_stat_item { NUMA_HIT, /* allocated in intended node */ @@ -837,7 +823,7 @@ struct zone { int initialized; /* Write-intensive fields used from the page allocator */ - ZONE_PADDING(_pad1_) + CACHELINE_PADDING(_pad1_); /* free areas of different sizes */ struct free_area free_area[MAX_ORDER]; @@ -849,7 +835,7 @@ struct zone { spinlock_t lock; /* Write-intensive fields used by compaction and vmstats. */ - ZONE_PADDING(_pad2_) + CACHELINE_PADDING(_pad2_); /* * When free pages are below this point, additional steps are taken @@ -886,7 +872,7 @@ struct zone { bool contiguous; - ZONE_PADDING(_pad3_) + CACHELINE_PADDING(_pad3_); /* Zone statistics */ atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; @@ -1196,7 +1182,7 @@ typedef struct pglist_data { #endif /* CONFIG_NUMA */ /* Write-intensive fields used by page reclaim */ - ZONE_PADDING(_pad1_) + CACHELINE_PADDING(_pad1_); #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* @@ -1241,7 +1227,7 @@ typedef struct pglist_data { struct lru_gen_mm_walk mm_walk; #endif - ZONE_PADDING(_pad2_) + CACHELINE_PADDING(_pad2_); /* Per-node vmstats */ struct per_cpu_nodestat __percpu *per_cpu_nodestats; diff --git a/include/linux/page_counter.h b/include/linux/page_counter.h index 78a1c93..c141ea9 100644 --- a/include/linux/page_counter.h +++ b/include/linux/page_counter.h @@ -7,22 +7,13 @@ #include #include -#if defined(CONFIG_SMP) -struct pc_padding { - char x[0]; -} ____cacheline_internodealigned_in_smp; -#define PC_PADDING(name) struct pc_padding name -#else -#define PC_PADDING(name) -#endif - struct page_counter { /* * Make sure 'usage' does not share cacheline with any other field. The * memcg->memory.usage is a hot member of struct mem_cgroup. */ atomic_long_t usage; - PC_PADDING(_pad1_); + CACHELINE_PADDING(_pad1_); /* effective memory.min and memory.min usage tracking */ unsigned long emin; @@ -38,7 +29,7 @@ struct page_counter { unsigned long failcnt; /* Keep all the read most fields in a separete cacheline. */ - PC_PADDING(_pad2_); + CACHELINE_PADDING(_pad2_); unsigned long min; unsigned long low;