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Message-Id: <1407978746-20587-1-git-send-email-minchan@kernel.org> Date: Thu, 14 Aug 2014 10:12:24 +0900 From: Minchan Kim <minchan@...nel.org> To: Andrew Morton <akpm@...ux-foundation.org> Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org, Sergey Senozhatsky <sergey.senozhatsky@...il.com>, Jerome Marchand <jmarchan@...hat.com>, juno.choi@....com, seungho1.park@....com, Luigi Semenzato <semenzato@...gle.com>, Nitin Gupta <ngupta@...are.org>, Seth Jennings <sjennings@...iantweb.net>, Dan Streetman <ddstreet@...e.org>, ds2horner@...il.com, Minchan Kim <minchan@...nel.org> Subject: [PATCH 1/3] zsmalloc: move pages_allocated to zs_pool Pages_allocated has counted in size_class structure and when user want to see total_size_bytes, it gathers all of value 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. Even, this patch moves the variable from size_class to zs_pool so it reduces memory footprint (from [255 * 8byte] to [sizeof(atomic_t)]) but it introduce new atomic opearation but it's not a big deal because atomic operation is called on slow path of zsmalloc where it allocates/free zspage unit, not object. Signed-off-by: Minchan Kim <minchan@...nel.org> --- mm/zsmalloc.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 4e2fc83cb394..2f21ea8921dc 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_t pages_allocated; }; /* @@ -1027,8 +1025,8 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size) return 0; set_zspage_mapping(first_page, class->index, ZS_EMPTY); + atomic_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; @@ -1081,14 +1079,12 @@ 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_sub(class->pages_per_zspage, &pool->pages_allocated); free_zspage(first_page); + } } EXPORT_SYMBOL_GPL(zs_free); @@ -1184,12 +1180,9 @@ 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; + npages = atomic_read(&pool->pages_allocated); return npages << PAGE_SHIFT; } EXPORT_SYMBOL_GPL(zs_get_total_size_bytes); -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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