From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: [PATCH v16 02/22] mm/page_idle: no unlikely double check for idle page counting Date: Sat, 11 Jul 2020 08:58:36 +0800 Message-ID: <1594429136-20002-3-git-send-email-alex.shi@linux.alibaba.com> References: <1594429136-20002-1-git-send-email-alex.shi@linux.alibaba.com> Return-path: In-Reply-To: <1594429136-20002-1-git-send-email-alex.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com, kirill@shutemov.name As func comments mentioned, few isolated page missing be tolerated. So why not do further to drop the unlikely double check. That won't cause more idle pages, but reduce a lock contention. This is also a preparation for later new page isolation feature. Signed-off-by: Alex Shi Cc: Andrew Morton Cc: Johannes Weiner Cc: Matthew Wilcox Cc: Hugh Dickins Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/page_idle.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/mm/page_idle.c b/mm/page_idle.c index 057c61df12db..5fdd753e151a 100644 --- a/mm/page_idle.c +++ b/mm/page_idle.c @@ -32,19 +32,11 @@ static struct page *page_idle_get_page(unsigned long pfn) { struct page *page = pfn_to_online_page(pfn); - pg_data_t *pgdat; if (!page || !PageLRU(page) || !get_page_unless_zero(page)) return NULL; - pgdat = page_pgdat(page); - spin_lock_irq(&pgdat->lru_lock); - if (unlikely(!PageLRU(page))) { - put_page(page); - page = NULL; - } - spin_unlock_irq(&pgdat->lru_lock); return page; } -- 1.8.3.1