From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: [PATCH v9 14/20] mm/lru: introduce the relock_page_lruvec function Date: Mon, 2 Mar 2020 19:00:24 +0800 Message-ID: <1583146830-169516-15-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 , Thomas Gleixner , Andrey Ryabinin , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org During the lruvec locking, a new page's lruvec is may same as previous one. Thus we could save a re-locking, and only change lock iff lruvec is new. Function named relock_page_lruvec following Hugh Dickins' patch. Signed-off-by: Alex Shi Cc: Johannes Weiner Cc: Andrew Morton Cc: Thomas Gleixner Cc: Andrey Ryabinin Cc: Matthew Wilcox Cc: Mel Gorman Cc: Konstantin Khlebnikov Cc: Hugh Dickins Cc: Tejun Heo Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org --- include/linux/memcontrol.h | 36 ++++++++++++++++++++++++++++++++++++ mm/vmscan.c | 8 ++------ 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index b8a04f0a2ab8..f60009580d2a 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1307,6 +1307,42 @@ static inline void dec_lruvec_page_state(struct page *page, mod_lruvec_page_state(page, idx, -1); } +/* Don't lock again iff page's lruvec locked */ +static inline struct lruvec *relock_page_lruvec_irq(struct page *page, + struct lruvec *locked_lruvec) +{ + struct pglist_data *pgdat = page_pgdat(page); + struct lruvec *lruvec; + + lruvec = mem_cgroup_page_lruvec(page, pgdat); + + if (likely(locked_lruvec == lruvec)) + return lruvec; + + if (unlikely(locked_lruvec)) + unlock_page_lruvec_irq(locked_lruvec); + + return lock_page_lruvec_irq(page); +} + +/* Don't lock again iff page's lruvec locked */ +static inline struct lruvec *relock_page_lruvec_irqsave(struct page *page, + struct lruvec *locked_lruvec, unsigned long *flags) +{ + struct pglist_data *pgdat = page_pgdat(page); + struct lruvec *lruvec; + + lruvec = mem_cgroup_page_lruvec(page, pgdat); + + if (likely(locked_lruvec == lruvec)) + return lruvec; + + if (unlikely(locked_lruvec)) + unlock_page_lruvec_irqrestore(locked_lruvec, *flags); + + return lock_page_lruvec_irqsave(page, flags); +} + #ifdef CONFIG_CGROUP_WRITEBACK struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb); diff --git a/mm/vmscan.c b/mm/vmscan.c index a58cd5ee9ea1..de925bd629eb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4325,14 +4325,10 @@ void check_move_unevictable_pages(struct pagevec *pvec) for (i = 0; i < pvec->nr; i++) { struct page *page = pvec->pages[i]; - struct lruvec *new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); pgscanned++; - if (lruvec != new_lruvec) { - if (lruvec) - unlock_page_lruvec_irq(lruvec); - lruvec = lock_page_lruvec_irq(page); - } + + lruvec = relock_page_lruvec_irq(page, lruvec); if (!TestClearPageLRU(page) || !PageUnevictable(page)) continue; -- 1.8.3.1