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Mon, 01 Dec 2025 12:22:09 -0800 (PST) MIME-Version: 1.0 References: <20251124193258.GB476776@cmpxchg.org> <20251125213126.GB135004@cmpxchg.org> <7665130c511e3cd00f83e8b14de2b78e08830887.camel@surriel.com> <7e44e8654eb0ed5e0f590b3d705b258772dadb57.camel@surriel.com> <20251201164338.GA430226@cmpxchg.org> In-Reply-To: <20251201164338.GA430226@cmpxchg.org> From: Barry Song Date: Tue, 2 Dec 2025 04:21:56 +0800 X-Gm-Features: AWmQ_bmDfHWyQfsGvK_qFrw5gpxxJKnNf3RxMfaofT4QIFsdlQ7oQ0iWuca2RK4 Message-ID: Subject: Re: [PATCH RFC] mm: ghost swapfile support for zswap To: Johannes Weiner Cc: Chris Li , Nhat Pham , Rik van Riel , Andrew Morton , Kairui Song , Kemeng Shi , Baoquan He , Yosry Ahmed , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org, pratmal@google.com, sweettea@google.com, gthelen@google.com, weixugc@google.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 71B0FC0019 X-Stat-Signature: od7549bu6ccir5kfzokomryac5z5mmu6 X-Rspamd-Pre-Result: action=add header; module=dmarc; Action set by DMARC X-Rspam-User: X-Rspam: Yes X-HE-Tag: 1764620530-7385 X-HE-Meta: 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 0f0VdgQm /tK0XxrcZFzA/JuU2fORPuScTc14hANVpf0edVvR1r3WRa6GCmmyNlmfMqvOpGpugnsdd/6QdDv8aklyx4SEUOSLRK+BhlRSwzq5jps/qs6iXl7OJhq8SfI0PCxuBRUwwjH+eCunzJ7naUe+Qh5avbo3dCpabiXb6tP9ezwC8szPC7jy6AFFDQhCB9f0us2lc5JMUoKDEqMZoZgdUXj25F+6PlNhdWZ4IAh37WauukULSlgFPeMf8jvWVMEK83wRvIR8FUkpMSOmGapAGfiJ+5NlpRPI41hFcnbaGijBPB6m4M1yq6b1tyiRDNIMsO3kQxWiIPCJEHK9RuqsNrGX/0CLDGFBX8eRrRAwl3fVQgto/VJxJuO0i/dIUWo95Hy5d97ILYbkyuJfQkBB8FWBhGchB85GUfa/aBM555ba5KnynhjPdAdSUnKQsRlSMSWXhOKbp X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Tue, Dec 2, 2025 at 12:43=E2=80=AFAM Johannes Weiner wrote: [...] > > For the benefit of anybody following this from the sidelines, the > third zswap maintainer also expressed concerns about Chris's proposal > upthread. He works for the same company as Chris. > > The reality is that Chris is failing to convince others of his design > direction, and is now obviously resorting to manipulation and hominem > attacks. > > During the course of this thread, Chris has asked for "a little faith" > that his idea will work for all stated requirements, without deeming > it necessary to explain how. > > When probed on technical details, he stated that he doesn't like to > plan that far ahead, and prefers having somebody else iron out the > implementation details. He also referred to high-level slides from his > LSFMM '24 session - which was received thusly[1]: > > Matthew Wilcox agreed, warning Li that he was setting himself up for "a= world of pain". > > Jan Kara said that existing filesystem designs are not suited to this t= ask > > Hildenbrand said that this plan was introducing too much complexity > > His first response to criticism was to invoke his <4 week status of > swap maintainer. > > Meanwhile, the design direction that Chris is construing as a single > company conspiracy is anything but. The collaborative origins of these > patches are well documented. Chris was CC'd on those RFCs. He notably > did not engage in them. He is now lying about the narrative and > choosing to attack these patches in bad faith and out of context. > > This pattern of behavior gives me low confidence that Chris is able to > collaborate and compromise on a design that works for all users. > > And while Chris has been quite vocal and opinionated in mailing list > discussions, his actual code contributions to the kernel do not > instill confidence that he can solve this problem by himself, either. Hi Johannes, Nhat, and Chris, Thanks for your valuable input and discussion on swap virtualization and swap.tier. I=E2=80=99m not an authority on zswap or swap, but I strongly encourage eve= ryone to stay calm and focus on technical issues. Together, we can make swap work be= tter. Perhaps we should allow Nhat and Chris additional time to clarify the technical details and address more of the code? Personally, I have had a positive collaboration with Chris on resolving the mTHP swap allocation contiguous issue, and I have also seen the swap table emerge as a solid design. I therefore expect more great contributions from Chris. Meanwhile, I share a common experience with Nhat in addressing abus= ive language together in a specific thread, and I continue to see Nhat doing excellent work. For these reasons, I hold deep shared respect and appreciat= ion for Nhat, and I am 100% looking forward to collaborating more with him. Looking forward to seeing more code and technical details from both Nhat and Chris. > > [1] https://lwn.net/Articles/974587/ Thanks Barry