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AJvYcCV+qKYxF/nLdTufZdeNL/zimWiYzxDe6zJaXIMn1DbS62mNYhXYL4cqvPyUZDttrF1UXhBegKcCbjskwB5XZoC7Fug= X-Gm-Message-State: AOJu0YzFvs+ck57DKvDdNhFzrhmddC48xMXOtg4TENYdCfmLPB/7XA/x llvkOguJf6sQStiZLe7axTHAgVEdlYnSO2UBYfP0cBRpf/qfNy74uBgcpZFkA16y1Wmpea6aAC5 BRt7tl0jrm38hxny/YYvydNvvj6jFlZl5nwVC X-Google-Smtp-Source: AGHT+IHDPmf6+ClOONhZk9Nso0W2EhtmarkGmfQfspzadJOIG/HidFZptnUBVVUkiTtl79ePE2onlXdj3/v0NAL6Wxc= X-Received: by 2002:a17:907:97c3:b0:a7a:bae8:f2a1 with SMTP id a640c23a62f3a-a8392a03c21mr69498266b.42.1723759841582; Thu, 15 Aug 2024 15:10:41 -0700 (PDT) MIME-Version: 1.0 References: <20240814171800.23558-1-me@yhndnzj.com> <20240815150819.9873910fa73a3f9f5e37ef4d@linux-foundation.org> In-Reply-To: <20240815150819.9873910fa73a3f9f5e37ef4d@linux-foundation.org> From: Yosry Ahmed Date: Thu, 15 Aug 2024 15:10:05 -0700 Message-ID: Subject: Re: [PATCH] mm/memcontrol: respect zswap.writeback setting from parent cg too To: Andrew Morton Cc: Nhat Pham , Mike Yuan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, Muchun Song , Shakeel Butt , Roman Gushchin , Michal Hocko , Johannes Weiner Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E97E340012 X-Stat-Signature: zkagsu6w7cgcwmw7qn94b7bc468t6kmr X-Rspam-User: X-HE-Tag: 1723759843-515387 X-HE-Meta: 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 fL3oBQvA fwyVXQ/G+P0RPLXJI317Dd4UCBZLwuy/7beEjgyPEpVbJHWh5Hci3X/9Afn5u1w9eV3xxmyGv93mNIQFPoRHVKWl3MBZVvVmNmp3VOKQ4cPJGBkkNYkZ/jcUpYOpX0azI4fALEd/N0kTc+oEOYJbvVp7dgcTVQxgtMwLq0hGQmAHMAcudCCS5Yjj/wBT5fGzhDrWLUVmyR3NBuvTIdr9XZ/suwX4vwIOr5Gm0GG4yC5pMIA1fK/mkRrsnSMeBELS6N6MZ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000028, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Aug 15, 2024 at 3:08=E2=80=AFPM Andrew Morton wrote: > > On Thu, 15 Aug 2024 12:12:26 -0700 Nhat Pham wrote: > > > > Yeah, I thought about the other way around and reached the same > > > conclusion. > > > And there's permission boundary in the mix too - if root disables zsw= ap > > > writeback for its cgroup, the subcgroups, which could possibly be own= ed > > > by other users, should not be able to reenable this. > > > > Hmm yeah, I think I agree with your and Yosry's reasonings :) It > > doesn't affect our use case AFAICS, and the code looks solid to me, > > so: > > > > Reviewed-by: Nhat Pham > > But you'd still like an update to Documentation/admin-guide/cgroup-v2.rst= ? Yeah I'd rather see a v2 with updated docs, and hopefully a selftest if the existing tests problem is resolved. Also, do we want a Fixes tag and to backport this so that current users get the new behavior ASAP?