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:   Tue, 4 Apr 2023 19:32:09 +0200
From:   Michal =?utf-8?Q?Koutn=C3=BD?= <mkoutny@suse.com>
To:     Shakeel Butt <shakeelb@google.com>
Cc:     Yosry Ahmed <yosryahmed@google.com>, Tejun Heo <tj@kernel.org>,
        Josef Bacik <josef@toxicpanda.com>,
        Jens Axboe <axboe@kernel.dk>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Muchun Song <muchun.song@linux.dev>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vasily Averin <vasily.averin@linux.dev>,
        cgroups@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        bpf@vger.kernel.org, Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH v3 4/8] memcg: replace stats_flush_lock with an atomic
Message-ID: <20230404173209.fuw2wdbhbzdgszc6@blackpad>
References: <20230330191801.1967435-1-yosryahmed@google.com>
 <20230330191801.1967435-5-yosryahmed@google.com>
 <20230404165258.ie6ttxobbmgn62hs@blackpad>
 <CALvZod5Y+quOS1XQvVBTvv7FRs3455j_79f0GoR+FqCFzbwkuA@mail.gmail.com>
 <CALvZod7Ao-VmB4as+VHsR+awW1jmOA18uVM7qk21mVsXTOYC2A@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="tp4kmk7uybolwv2d"
Content-Disposition: inline
In-Reply-To: <CALvZod7Ao-VmB4as+VHsR+awW1jmOA18uVM7qk21mVsXTOYC2A@mail.gmail.com>
Precedence: bulk


--tp4kmk7uybolwv2d
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Tue, Apr 04, 2023 at 10:21:33AM -0700, Shakeel Butt <shakeelb@google.com> wrote:
> > Yes indeed it is. Basically we want to avoid unconditional cache
> > dirtying. This pattern is also used at other places in the kernel like
> > qspinlock.

Thanks for confirmation.

(I remembered the commit 873f64b791a2 ("mm/memcontrol.c: remove the
redundant updating of stats_flush_threshold"). But was slightly confused
why would it be open-coded every time.)

> Oh also take a look at
> https://lore.kernel.org/all/20230404052228.15788-1-feng.tang@intel.com/

Thanks for the link.

Michal

--tp4kmk7uybolwv2d
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iHUEABYKAB0WIQTrXXag4J0QvXXBmkMkDQmsBEOquQUCZCxfFAAKCRAkDQmsBEOq
ubDdAP9UYeeNxfHY8xeftxD/DsD9BcOlaSaQPTOhztUjOJOmEwD+PjYu9+lFlKNJ
In8lwXw/ZwMTHOjEVMnHwxc+TNnpwQk=
=LYWU
-----END PGP SIGNATURE-----

--tp4kmk7uybolwv2d--