diff mbox series

[v3,2/2] mm/swap: remove swap_cache_info statistics

Message ID 20220625093346.48894-3-linmiaohe@huawei.com (mailing list archive)
State New
Headers show
Series A few cleanup and fixup patches for swap | expand

Commit Message

Miaohe Lin June 25, 2022, 9:33 a.m. UTC 
swap_cache_info are not statistics that could be easily used to tune system
performance because they are not easily accessile. Also they can't provide
really useful info when OOM occurs. Remove these statistics can also help
mitigate unneeded global swap_cache_info cacheline contention.

Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/swap_state.c | 17 -----------------
 1 file changed, 17 deletions(-)
diff mbox series

Patch

diff --git a/mm/swap_state.c b/mm/swap_state.c
index dd142624172b..e166051566f4 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -59,24 +59,11 @@  static bool enable_vma_readahead __read_mostly = true;
 #define GET_SWAP_RA_VAL(vma)					\
 	(atomic_long_read(&(vma)->swap_readahead_info) ? : 4)
 
-#define INC_CACHE_INFO(x)	data_race(swap_cache_info.x++)
-#define ADD_CACHE_INFO(x, nr)	data_race(swap_cache_info.x += (nr))
-
-static struct {
-	unsigned long add_total;
-	unsigned long del_total;
-	unsigned long find_success;
-	unsigned long find_total;
-} swap_cache_info;
-
 static atomic_t swapin_readahead_hits = ATOMIC_INIT(4);
 
 void show_swap_cache_info(void)
 {
 	printk("%lu pages in swap cache\n", total_swapcache_pages());
-	printk("Swap cache stats: add %lu, delete %lu, find %lu/%lu\n",
-		swap_cache_info.add_total, swap_cache_info.del_total,
-		swap_cache_info.find_success, swap_cache_info.find_total);
 	printk("Free swap  = %ldkB\n",
 		get_nr_swap_pages() << (PAGE_SHIFT - 10));
 	printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));
@@ -133,7 +120,6 @@  int add_to_swap_cache(struct page *page, swp_entry_t entry,
 		address_space->nrpages += nr;
 		__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
 		__mod_lruvec_page_state(page, NR_SWAPCACHE, nr);
-		ADD_CACHE_INFO(add_total, nr);
 unlock:
 		xas_unlock_irq(&xas);
 	} while (xas_nomem(&xas, gfp));
@@ -173,7 +159,6 @@  void __delete_from_swap_cache(struct folio *folio,
 	address_space->nrpages -= nr;
 	__node_stat_mod_folio(folio, NR_FILE_PAGES, -nr);
 	__lruvec_stat_mod_folio(folio, NR_SWAPCACHE, -nr);
-	ADD_CACHE_INFO(del_total, nr);
 }
 
 /**
@@ -349,12 +334,10 @@  struct page *lookup_swap_cache(swp_entry_t entry, struct vm_area_struct *vma,
 	page = find_get_page(swap_address_space(entry), swp_offset(entry));
 	put_swap_device(si);
 
-	INC_CACHE_INFO(find_total);
 	if (page) {
 		bool vma_ra = swap_use_vma_readahead();
 		bool readahead;
 
-		INC_CACHE_INFO(find_success);
 		/*
 		 * At the moment, we don't support PG_readahead for anon THP
 		 * so let's bail out rather than confusing the readahead stat.