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;
Message-ID: <8427ebb5-61d0-f0ad-3bfa-6aaf575427e4@suse.cz>
Date:   Mon, 12 Jun 2023 11:44:39 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.2
Subject: Re: [PATCH v4 0/3] page_owner: print stacks and their counter
Content-Language: en-US
To:     Andrew Morton <akpm@linux-foundation.org>,
        Oscar Salvador <osalvador@suse.de>
Cc:     Alexander Potapenko <glider@google.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Michal Hocko <mhocko@suse.com>,
        Eric Dumazet <edumazet@google.com>,
        Waiman Long <longman@redhat.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Marco Elver <elver@google.com>,
        Andrey Konovalov <andreyknvl@gmail.com>
References: <20230421101415.5734-1-osalvador@suse.de>
 <CAG_fn=UzFaHrM2X0_X=9aRPe5Wcmzj_snAbY=GJCj8__h9PxCg@mail.gmail.com>
 <7718244879ff2b696ea9cbb744cb3805@suse.de>
 <20230609145505.dc30b7712779d990aba64372@linux-foundation.org>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <20230609145505.dc30b7712779d990aba64372@linux-foundation.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 6/9/23 23:55, Andrew Morton wrote:
> On Mon, 24 Apr 2023 05:54:59 +0200 Oscar Salvador <osalvador@suse.de> wrote:
> 
>> > Given that no other stackdepot user needs these counters, maybe it
>> > should be cleaner to store an opaque struct along with the stack,
>> > passing its size to stack_depot_save(), and letting users access it
>> > directly using the stackdepot handler.
>> > 
>> > I am also wondering if a separate hashtable mapping handlers to
>> > counters would solve the problem for you?
>> 
>> Let us see first if with the changes from above the code gets to a more
>> generic and clean stage, if not we can explore further options.
> 
> Alexander, does this approach sound reasonable to you?

Note this is a v4 thread; there was (and the version in mm-unstable is) v5,
where the latest was Alexander requesting further changes:

https://lore.kernel.org/all/CAG_fn%3DUJgnLFGgpkXbMeD6axZN_ifEPHvWpy2_oiPyG1a6PXng@mail.gmail.com/

> The overall feature seems useful, although I'm not seeing any positive
> reviewer feedback.