From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2BCC620ADF8 for ; Tue, 14 Jul 2026 11:17:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784027861; cv=none; b=qXX1AkhT8u3eDkOxOjKrP5oIExRGDPUGafeRZfbC8M6WV7q0H/n1cCzPMamQKXDFtCg/7JjEo9lkeWuvIs7nPQ0WoYNuK8oQkQ4ok9zBPyf1wrB5GcUD0lVeeM0uUqjA353t2DsZl8D2io6NDbmO2LpicbO4V++VRH86DBqfNPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784027861; c=relaxed/simple; bh=R2SemUfGDaxIvvuhVsUSqWTCbeV4a24xddbL8Y2wUhU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=F+CmQJSg9GMeVK5jFEoFTieIyDv3E33wW9kQRt1OcgqMGRhq0UyWONJmdVvzRuR3xxadAariMzhTBSeva9InIQyD+vb0erNL+/b5TIOK28SdkdehPhnGMaJiwZ0dvpIpVZnYU8W8MwMMWAXNmU7YCNfyDZngzwBcCJ7gq7Ilz9Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=evQYv6xu; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="evQYv6xu" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 60221497; Tue, 14 Jul 2026 04:17:35 -0700 (PDT) Received: from [10.164.19.52] (unknown [10.164.19.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C36883F93E; Tue, 14 Jul 2026 04:17:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784027859; bh=R2SemUfGDaxIvvuhVsUSqWTCbeV4a24xddbL8Y2wUhU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=evQYv6xufZcgX7C01IfbaWPF1KL5BXIRm6RemT40GvFByo89ShBnyYxaRdbWtgdR4 6uwMLKuHrePOTAGGp16GO0SYsIj2itt6cgaLOmrIB935g9LczD611XLlLKDioQB509 0k+am8MDEo3T9w7WyLpdalRhKIQAUOmt0DWnvppE= Message-ID: Date: Tue, 14 Jul 2026 16:47:33 +0530 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 v6 0/6] mm/vmalloc: Speed up ioremap, vmalloc and vmap with contiguous memory To: Anshuman Khandual , Wen Jiang , Andrew Morton Cc: catalin.marinas@arm.com, linux-mm@kvack.org, urezki@gmail.com, will@kernel.org, Xueyuan.chen21@gmail.com, ajd@linux.ibm.com, david@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, rppt@kernel.org, ryan.roberts@arm.com, Wen Jiang References: <20260709073823.6643-1-jiangwen6@xiaomi.com> <20260709160805.26e63bae89dd03cf2951104e@linux-foundation.org> <929dedc2-eea3-4153-be6d-d2dd727fed89@arm.com> From: Dev Jain Content-Language: en-US In-Reply-To: <929dedc2-eea3-4153-be6d-d2dd727fed89@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 14/07/26 2:06 pm, Anshuman Khandual wrote: > > > On 10/07/26 2:24 PM, Wen Jiang wrote: >> On Fri, 10 Jul 2026 at 07:08, Andrew Morton wrote: >>> >>> On Thu, 9 Jul 2026 15:38:17 +0800 Wen Jiang wrote: >>> >>>> This patchset accelerates ioremap, vmalloc, and vmap when the memory >>>> is physically fully or partially contiguous. >>> >>> Thanks, I added this to mm.git's mm-new branch for wider testing. >>> >>> AI review asked some questions, and some of them are new since the v5 >>> series: >>> https://sashiko.dev/#/patchset/20260709073823.6643-1-jiangwen6@xiaomi.com >> >> Hi Andrew, >> >> I've gone through the Sashiko findings: >> >> - Patch 1 (find_num_contig): Over-interpretation. No new hugetlbfs hstate >> is added. The extra sizes are only used by init_mm kernel mappings via. > > But not sure if that is a right approach. If these multi CONT_PTE > sized mappings need to be supported in vmalloc() but without adding > corresponding HugeTLB sizes, probably these required helpers could > just be factored outside HugeTLB. The problem is that the existing vmalloc-huge code reuses the hugetlb helpers because it is easier that way. If you really look at it, num_contig_ptes(), set_huge_pte_at() and arch_make_huge_pte() do not have anything to do with hugetlbfs, but with huge mappings. It is unfortunate that these helpers are sitting in hugetlbpage.c . Really these functions should be pulled out of CONFIG_HUGETLBFS and put into some common header - but I can't think of a clean solution to this. So I think for this series, the least we can do is add a comment to clarify that these helpers can be used by non-hugetlbfs mm code to set multiple huge mappings at the PTE level. >> >> - Patch 5/6 (NULL page): Invalid input. vmap() expects a fully populated >> array of valid struct page pointers. >> >> - Patch 6 (32-bit count << PAGE_SHIFT overflow): Pre-existing. This was >> already discussed in the V3 thread, and a separate fix was proposed >> there. >> >> Thanks, >> Wen >