From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH v21 18/19] mm/lru: introduce the relock_page_lruvec function Date: Tue, 10 Nov 2020 13:59:58 -0500 Message-ID: <20201110185958.GC850433@cmpxchg.org> References: <1604566549-62481-1-git-send-email-alex.shi@linux.alibaba.com> <1604566549-62481-19-git-send-email-alex.shi@linux.alibaba.com> <66d8e79d-7ec6-bfbc-1c82-bf32db3ae5b7@linux.alibaba.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=JVcNggoHnnZHnilf65d3Odr5BSO3kl6mZ2aAWXQzRAo=; b=pk0sA6n4GDC9Xw1ArnL9O5vFNkTR5jEvlt0tkXEf4OOrdrRf0iF57WkXkq+aZYt5md SOSYGeOwJSxgei8KKg5Yo31SLqDaLSsHfymGg1j+h3i5xP9aG3N3Ponj3RSQUSa3S+Da MAJrkym3VnKjHe2aMbbHNw47MDcHZDhsY95JowUiHyKM48Bt4wQnhEQcVMcrdx1F0wQ4 cqL0zycLg4WR6wrxM8A0O8Pahsaxszc2AP39S+/sfFz72xb9uTzEVB8x6wGdrjSFMGIg oWkRlt3BsWF82RX0mGXyCgQrt1W2lsZfBe7aYt7B3k8TF536jzWY+531OJzHc1fJTPDz nsCQ== Content-Disposition: inline In-Reply-To: <66d8e79d-7ec6-bfbc-1c82-bf32db3ae5b7-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alex Shi Cc: 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, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, iamjoonsoo.kim-Hm3cg6mZ9cc@public.gmane.org, richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, kirill-oKw7cIdHH8eLwutG50LtGA@public.gmane.org, alexander.duyck-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, rong.a.chen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, mhocko-IBi9RG/b67k@public.gmane.org, vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, shy828301-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Alexander Duyck , Thomas Gleixner , Andrey Ryabinin On Fri, Nov 06, 2020 at 03:50:22PM +0800, Alex Shi wrote: > From 6c142eb582e7d0dbf473572ad092eca07ab75221 Mon Sep 17 00:00:00 2001 > From: Alexander Duyck > Date: Tue, 26 May 2020 17:31:15 +0800 > Subject: [PATCH v21 18/19] mm/lru: introduce the relock_page_lruvec function > > Use this new function to replace repeated same code, no func change. > > When testing for relock we can avoid the need for RCU locking if we simply > compare the page pgdat and memcg pointers versus those that the lruvec is > holding. By doing this we can avoid the extra pointer walks and accesses of > the memory cgroup. > > In addition we can avoid the checks entirely if lruvec is currently NULL. > > Signed-off-by: Alexander Duyck > Signed-off-by: Alex Shi > Acked-by: Hugh Dickins > Acked-by: Johannes Weiner > 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 Acked-by: Johannes Weiner