Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 26 May 2022 09:58:42 +0800
From:   Muchun Song <songmuchun@bytedance.com>
To:     Roman Gushchin <roman.gushchin@linux.dev>
Cc:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        Dave Chinner <dchinner@redhat.com>,
        linux-kernel@vger.kernel.org,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Hillf Danton <hdanton@sina.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: Re: [PATCH v4 2/6] mm: shrinkers: introduce debugfs interface for
 memory shrinkers
Message-ID: <Yo7e0st/IiSpkfQR@FVFYT0MHHV2J.googleapis.com>
References: <20220525202600.2910982-1-roman.gushchin@linux.dev>
 <20220525202600.2910982-3-roman.gushchin@linux.dev>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220525202600.2910982-3-roman.gushchin@linux.dev>
Precedence: bulk

On Wed, May 25, 2022 at 01:25:56PM -0700, Roman Gushchin wrote:
> This commit introduces the /sys/kernel/debug/shrinker debugfs
> interface which provides an ability to observe the state of
> individual kernel memory shrinkers.
> 
> Because the feature adds some memory overhead (which shouldn't be
> large unless there is a huge amount of registered shrinkers), it's
> guarded by a config option (enabled by default).
> 
> This commit introduces the "count" interface for each shrinker
> registered in the system.
> 
> The output is in the following format:
> <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
> <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
> ...
> 
> To reduce the size of output on machines with many thousands cgroups,
> if the total number of objects on all nodes is 0, the line is omitted.
> 
> If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is
> printed as cgroup inode id. If the shrinker is not numa-aware, 0's are
> printed for all nodes except the first one.
> 
> This commit gives debugfs entries simple numeric names, which are not
> very convenient. The following commit in the series will provide
> shrinkers with more meaningful names.
> 
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>

Acked-by: Muchun Song <songmuchun@bytedance.com>

Thanks.