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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=oNt9MexY; 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 AE883606A31D for ; Tue, 20 Oct 2026 10:57:50 +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=oNt9MexY Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36B4D1F000C4; Tue, 20 Oct 2026 10:57:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792493870; bh=xLh3GTHbeQEaUVrh6opDuRvseOhCfKAJJU5WzZ/c3QE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=oNt9MexYHHjAFDpAtUK7Wg/Nr8gWi0LjtrU2RPEIVE6L3R/HVhBwT6fwIdWL7OPBU DBCp5AI0OuSXjyeTyVh7g2U2/uoyquZDzzYRi3bm8hpFcuZfaO7JxJFCOi3wvKdBGy l4kPE8ea1YuseBmAIEBLnyHOW+yqOzziNIT9Gx76yFYyrZqiFc28fubj2jdROq7cOu WYEYOjk434Y/yaSp2VDsPunN9I2cljeJm1vKoeaheAdZWzKKVc6U7jf7bNUw21ZGiS vmk5ZdgBhCmk7dv/i7sDGGMvhAzKERfJcpOr50xhm3aW33j/DmZPKO3Ruu2Md2egqA kqtQyXrExTjcQ== Message-ID: Date: Tue, 20 Oct 2026 12:57:46 +0200 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] hugetlb: retry private VMA locking when unmapping folios To: Daehyeon Ko <4ncienth@gmail.com> Cc: muchun.song@linux.dev, osalvador@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20261015170551.2656546-1-4ncienth@gmail.com> <23623534-a163-4ffa-8538-b5aff7daecaf@kernel.org> <20261020102012.1775940-1-4ncienth@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 10/20/26 12:20, Daehyeon Ko wrote: > Hi David, > > Yes, that makes sense. > > The per-index fault mutex excludes concurrent faults for the folio being > removed, while i_mmap_rwsem keeps the VMA in the mapping tree and excludes > concurrent page-table teardown. So the private resv_map lock is not needed > in this path. > > I tested the exact diff from your message on v7.3-rc5 with KASAN+LOCKDEP. > My unprivileged mprotect()/hole-punch reproducer completed 1,000 rounds > (64,000 hole punches) with no KASAN, lockdep, unexpected warning, oops, or > panic. > > Please consider my patch superseded by Josef's fix. > > One small typo in the quoted comment: "i_mmap_rwsem everybody" appears to > be missing "excludes". > > The quoted commit also predates the current linux-next policy change: > `Assisted-by` is no longer a recognized trailer. `generated-content.rst` > asks that tool-assisted discovery be stated in the changelog prose instead. > > Tested-by: Daehyeon Ko <4ncienth@gmail.com> Can you overhaul (shorten etc) the patch description and send it out for proper review? -- Cheers, David