From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: [PATCH v9 03/20] mm/page_idle: no unlikely double check for idle page counting Date: Mon, 2 Mar 2020 19:00:13 +0800 Message-ID: <1583146830-169516-4-git-send-email-alex.shi@linux.alibaba.com> References: <1583146830-169516-1-git-send-email-alex.shi@linux.alibaba.com> Return-path: In-Reply-To: <1583146830-169516-1-git-send-email-alex.shi-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, mgorman-3eNAlZScCAx27rWaFMvyedHuzzzSOjJt@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, khlebnikov-XoJtRXgx1JseBXzfvpsJ4g@public.gmane.org, daniel.m.jordan-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, yang.shi-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: Alex Shi , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 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-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- mm/page_idle.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/mm/page_idle.c b/mm/page_idle.c index 295512465065..914df63948b1 100644 --- a/mm/page_idle.c +++ b/mm/page_idle.c @@ -31,7 +31,6 @@ static struct page *page_idle_get_page(unsigned long pfn) { struct page *page; - pg_data_t *pgdat; if (!pfn_valid(pfn)) return NULL; @@ -41,13 +40,6 @@ static struct page *page_idle_get_page(unsigned long pfn) !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