From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: [PATCH 2/2] mm/page_alloc: use a single function to free page Date: Mon, 5 Nov 2018 16:58:20 +0800 Message-ID: <20181105085820.6341-2-aaron.lu@intel.com> References: <20181105085820.6341-1-aaron.lu@intel.com> Cc: Andrew Morton , =?UTF-8?q?Pawe=C5=82=20Staszewski?= , Jesper Dangaard Brouer , Eric Dumazet , Tariq Toukan , Ilias Apalodimas , Yoel Caspersen , Mel Gorman , Saeed Mahameed , Michal Hocko , Vlastimil Babka , Dave Hansen To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: Received: from mga07.intel.com ([134.134.136.100]:46184 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbeKESRF (ORCPT ); Mon, 5 Nov 2018 13:17:05 -0500 In-Reply-To: <20181105085820.6341-1-aaron.lu@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: We have multiple places of freeing a page, most of them doing similar things and a common function can be used to reduce code duplicate. It also avoids bug fixed in one function and left in another. Signed-off-by: Aaron Lu --- mm/page_alloc.c | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 91a9a6af41a2..2b330296e92a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4425,9 +4425,17 @@ unsigned long get_zeroed_page(gfp_t gfp_mask) } EXPORT_SYMBOL(get_zeroed_page); -void __free_pages(struct page *page, unsigned int order) +/* + * Free a page by reducing its ref count by @nr. + * If its refcount reaches 0, then according to its order: + * order0: send to PCP; + * high order: directly send to Buddy. + */ +static inline void free_the_page(struct page *page, unsigned int order, int nr) { - if (put_page_testzero(page)) { + VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); + + if (page_ref_sub_and_test(page, nr)) { if (order == 0) free_unref_page(page); else @@ -4435,6 +4443,11 @@ void __free_pages(struct page *page, unsigned int order) } } +void __free_pages(struct page *page, unsigned int order) +{ + free_the_page(page, order, 1); +} + EXPORT_SYMBOL(__free_pages); void free_pages(unsigned long addr, unsigned int order) @@ -4481,16 +4494,7 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, void __page_frag_cache_drain(struct page *page, unsigned int count) { - VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); - - if (page_ref_sub_and_test(page, count)) { - unsigned int order = compound_order(page); - - if (order == 0) - free_unref_page(page); - else - __free_pages_ok(page, order); - } + free_the_page(page, compound_order(page), count); } EXPORT_SYMBOL(__page_frag_cache_drain); @@ -4555,14 +4559,7 @@ void page_frag_free(void *addr) { struct page *page = virt_to_head_page(addr); - if (unlikely(put_page_testzero(page))) { - unsigned int order = compound_order(page); - - if (order == 0) - free_unref_page(page); - else - __free_pages_ok(page, order); - } + free_the_page(page, compound_order(page), 1); } EXPORT_SYMBOL(page_frag_free); -- 2.17.2