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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fyTFJvvg; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63727606A327 for ; Tue, 27 Oct 2026 12:11:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fyTFJvvg Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69E2D1F01829; Tue, 27 Oct 2026 12:11:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793103090; bh=tOOdVBp1yruXWIq0c9+0VPmPMq3Hl+/FoCSys8OoW54=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=fyTFJvvgoHCUYXMj/IaoGifAuZRrpVVmRm0YWBR7SS8Z+rFiw32VaDiWZNzK+dpaA WJ1Lq24I0FstYu9BVMQ2l7xaKdIseZxb3CQnUE+iZObnIRmtACAm0WoPX77OLmUSIH 19yfgfh8p+D/Ivyqrm+xNBOIaGJWBE4Vw0jE2HO1CWIH/Ft0puRpoceaanqUBG1qIC cqEFyvvohjOmgAvPbjJ9xONg68UUot+Y2k1fiIDKLrukLORNCG4Z3ByAaDfH/aihjO LIkJVMf1TXBUjuIEtjAGf+rRSuqrTliEXLtq7hwK28pgYXSi5sG47YOjGrNFx3O0Kc fwZHXMV0fAYIQ== Message-ID: Date: Tue, 27 Oct 2026 13:11:24 +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] mm: clear pmd in pmdp_invalidate() To: Guilherme Giacomo Simoes , akpm@linux-foundation.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20261027113813.1332096-1-trintaeoitogc@gmail.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 10/27/26 12:38, Guilherme Giacomo Simoes wrote: > when attempt to do a madvise in a chunk of memory allocated by mmap, the > folio_split is called to split a portion of memory, and despite the path > leads to pmd_mkinvalid() they do not clear the pmd and clearer wording, > leading to a BUG_ON inside page_table_check_set() because the map count > is more than 1. > > Call the page_table_check_pmd_clear() inside pmdp_invalidate() generic > function to ensure that the pmd will have they map count decrement. > The subject + description is rather confusing: you are not "clearing the pmd", you tell page-table-check that the PMD was cleared. This is all about apge-table-check. Can you post the actual kernel splat you ran into? Or is this generated by an LLM? Thanks! -- Cheers, David