From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6D8E392C25 for ; Tue, 7 Jul 2026 13:48:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783432086; cv=none; b=KpW/6OUg5trpQuVKzmrb7BnpGwQcXIG2ucPh/B0faQX1EJp9qizyvrc10Erh0PUbqhDofxNTiBQPLqgFPVyc7mNCsSPQvezJHY9dNr4UDhyb+/r0fSfPyI0SorHkzfrvYlxGSwjHBz1DgRyJIaQUO9tzkAVf6J3l4dBwKxyv4cE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783432086; c=relaxed/simple; bh=l0Ezkz56cbuG4oKGyb3eOpoTosawm/DiJ7z5cqsg2mg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HtMML0UkB1YRcrgLCHCj4Xy6wT4ZMtz6Pf0G8bjK+1DXDrONo235x3Jtnsz6ua1vsGcjqwdjJuadx8srRN1QebE3Gdek84wjR7xaDH5TgX77yVOiYzzx10Xu3V3WnKkEGNs1+t9q4dNvZ3YxpJHZGVoSTfsTdnpE9AOD+oEOam4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cwb2Vl3k; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cwb2Vl3k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 545D41F000E9; Tue, 7 Jul 2026 13:47:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783432085; bh=dswxlVoUXjFFWOz2smDnQwb5mPOff9g7KEXwMGxsrFE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=cwb2Vl3kw9B1Yir0mxFjBBURXZlilfgRyuUYMiigWxIRGDyiH/388LhuNWxlUSJhO l7848zEObF1rOs8l9B8j+adstLF2PkfshMZKvtDNsPxhlNqLRD8dAfe1yLQdFWG26F 7sFqZ0GDboY0G2KCcxJnHSRrA3ERO/Zgnbqbv1x9UPtDRMH0qUK3Eg5ZWDQZjp7tW6 4BDMFXllHZrkwMwEs/WQEel5Xao1HDIpV5grS7YI50zjkv7CBQolEG57uW5e6oqp2v OldPhFQ6qiCA9o2/4iYm+X1UPYg/5zk9OsD6ZDxp9N5kxgWDMAGiUak1Uk7YRd3Icw Rvrl6Kc36s0ug== Message-ID: Date: Tue, 7 Jul 2026 15:47:57 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 04/12] mm/memory: Batch set uffd-wp markers during zapping To: Dev Jain , akpm@linux-foundation.org, ljs@kernel.org, chrisl@kernel.org, kasong@tencent.com, hughd@google.com, liam@infradead.org Cc: riel@surriel.com, vbabka@kernel.org, harry@kernel.org, jannh@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, baolin.wang@linux.alibaba.com, pfalcato@suse.de, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260526063635.61721-1-dev.jain@arm.com> <20260526063635.61721-5-dev.jain@arm.com> <562addc1-b334-4258-b0d2-0154ffed061b@arm.com> <0654116a-235d-4eb0-9970-414322645aa3@arm.com> 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 6/27/26 11:00, Dev Jain wrote: > > > On 23/06/26 3:31 pm, Dev Jain wrote: >> >> >> On 16/06/26 7:13 pm, David Hildenbrand (Arm) wrote: >>> >>> Avoid talking about "next patch". Phrase it as "In preparation for batching...". >>> >>> >>> Below you have >>> >>> >>> Could we easily extend set_ptes() to allow for non-present -> non-present with >>> nr > 1? >> >> We could have a set_nonpresent_ptes() in general, but then for some non-present >> configs like in this patch, we don't need to change the pfn, while in some >> configs like setting swp ptes in one go (like I do in later patches) we have >> an underlying pfn. So I don't see an obvious simplification with a common >> helper for non-present -> non-present for nr > 1. > > I think a "non-present" entry always means a softleaf? In that case, we can > simply branch on softleaf_has_pfn(). We could, but it might turn the overall function more expensive by throwing in additional runtime checks that the compiler will not really optimize out. Worth playing with. -- Cheers, David