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b=OyHe/4xAP6WCorugyhRh2YGYy1BO8A93QVK/QxBl2JzDgugFa9HrveviyxJbzlrWf N33EqbM2ND75BtjehLURhzxhyjHyl6NniMAEsJfnDZYeTbAg3hK+IvI3x0YjG4vo4E n+yqhpr8ii7uWk60fU5cm/53Qe9WInE/L2P/WP2PE5NuZdk1NKioHg/186/EFHaLJQ QJA1prI/67wzJVaDtoSH4dTgG+vmi/JAJ+74NvRX8dmeMW6VdBZA/QHDC4jYJnMqfU FvOAocq2S8xNemSBNQtWykHxyrmVAymLc2QykuIICKnMqKWn3A073a8l7gcEpSJiVL J/Kct1lCTTz1g== Message-ID: <3c73fe54-68d8-41f3-8f9f-06c4a1891e01@kernel.org> Date: Tue, 27 Oct 2026 13:53:34 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] mm: memory: fix truncation removing mapped folios To: Baolin Wang , akpm@linux-foundation.org Cc: ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, jack@suse.cz, pfalcato@suse.de, ayushr@modal.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <2ba579e8-06fb-41f5-9eb2-f02b2aabe29b@kernel.org> <87e32afd-75de-4407-8f0c-fb70b40d5eca@linux.alibaba.com> <81ee2c92-f342-4f7f-aacd-d9558e67a980@kernel.org> <4880d4ff-8486-4e22-9923-bd4f2407b1cb@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/27/26 13:50, Baolin Wang wrote: > > > On 10/27/26 6:55 PM, David Hildenbrand (Arm) wrote: >> On 10/27/26 11:35, Baolin Wang wrote: >>> >>> >>> >>> Sure. >>> >>> >>> IMHO, I'm not a big fan of adding two pmd_none() checks just to avoid an >>> uncommon concurrent sync. >> >> It's what we already had. We had to: one for handling pmd_none() directly and >> one for handling zapping while splitting (file THPs). >> >> We just managed to let the second also handle the final piece of the former. >> >> Anyhow, let's get this fixed. >> >> If you think the code is clearer your way (where I disagree) > > Fair enough. Though I have a different taste, I'd still like to make the > maintainer happy. Don't worry, it's hard to make me unhappy :) (just a bit overloaded right now) > I'll send out v6 tomorrow following your suggestion. > That looks good. Are you planning on following up with the memory barrier optimization for smaller folios? I hope below doesn't end up in some performance degradation. -- Cheers, David