[PATCH v5 1/4] zsmalloc: move pages_allocated to zs_pool
From: Minchan Kim <minchan@kernel.org>
Date: 2014-08-25 00:05:28
Also in:
lkml
Subsystem:
memory management, the rest, zsmalloc compressed slab memory allocator · Maintainers:
Andrew Morton, Linus Torvalds, Minchan Kim, Sergey Senozhatsky
pages_allocated has counted in size_class structure and when user of zsmalloc want to see total_size_bytes, it should gather all of count from each size_class to report the sum. it's not bad if user don't see the value often but if user start to see the value frequently, it would be not a good deal for performance pov. This patch moves the count from size_class to zs_pool so it could reduce memory footprint (from [255 * 8byte] to [sizeof(atomic_long_t)]). Reviewed-by: Dan Streetman <redacted> Signed-off-by: Minchan Kim <minchan@kernel.org> --- mm/zsmalloc.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 94f38fac5e81..2a4acf400846 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c@@ -199,9 +199,6 @@ struct size_class { spinlock_t lock; - /* stats */ - u64 pages_allocated; - struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; };
@@ -220,6 +217,7 @@ struct zs_pool { struct size_class size_class[ZS_SIZE_CLASSES]; gfp_t flags; /* allocation flags used when growing pool */ + atomic_long_t pages_allocated; }; /*
@@ -1028,8 +1026,9 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size) return 0; set_zspage_mapping(first_page, class->index, ZS_EMPTY); + atomic_long_add(class->pages_per_zspage, + &pool->pages_allocated); spin_lock(&class->lock); - class->pages_allocated += class->pages_per_zspage; } obj = (unsigned long)first_page->freelist;
@@ -1082,14 +1081,13 @@ void zs_free(struct zs_pool *pool, unsigned long obj) first_page->inuse--; fullness = fix_fullness_group(pool, first_page); - - if (fullness == ZS_EMPTY) - class->pages_allocated -= class->pages_per_zspage; - spin_unlock(&class->lock); - if (fullness == ZS_EMPTY) + if (fullness == ZS_EMPTY) { + atomic_long_sub(class->pages_per_zspage, + &pool->pages_allocated); free_zspage(first_page); + } } EXPORT_SYMBOL_GPL(zs_free);
@@ -1185,12 +1183,7 @@ EXPORT_SYMBOL_GPL(zs_unmap_object); u64 zs_get_total_size_bytes(struct zs_pool *pool) { - int i; - u64 npages = 0; - - for (i = 0; i < ZS_SIZE_CLASSES; i++) - npages += pool->size_class[i].pages_allocated; - + u64 npages = atomic_long_read(&pool->pages_allocated); return npages << PAGE_SHIFT; } EXPORT_SYMBOL_GPL(zs_get_total_size_bytes);
--
2.0.0
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