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 8AB3C2D738B for ; Fri, 3 Oct 2025 17:05:23 +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=1759511125; cv=none; b=kp0zhiwvebNRpa2T+wPMrd5GSmKnzYaj3MThn7XrNIRZuRdkpBvSvbHPfhOnz2FDt5V3SYXJchDRhN4wW1i1c0gxaqjR2MA9+kTdWGmH/fYkPrg1Ts2mDAGeLN4ZDTN3gsVpkXwATojOhzUzXBAUFzK/ginxBePuMIvxGZaAzMo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759511125; c=relaxed/simple; bh=wAIBxaYGeVIBBgmlPnc939RMsjNGdAwoCTnXwDGYtpI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mUzHsmGyRahqdgARcOx4Ngs9nzi/BSlQJyDSw3UQ7qxPO14pxPYVO3jh4hl4Dgf+tUtH7S/9ZmE9KUTQFjV+WQ8CkbmXw+ysLcyHYKGwokKYRfr/ATGCqf8DDRR8UVH2of3eb9tfgutoECYgdoEhPilAfrbWdqke/nZqXnpjaE8= 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; 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 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 967C21655; Fri, 3 Oct 2025 10:05:14 -0700 (PDT) Received: from [10.163.65.114] (unknown [10.163.65.114]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DECF73F66E; Fri, 3 Oct 2025 10:05:16 -0700 (PDT) Message-ID: <0d55d763-81ff-4b99-bb13-3dbb9af53cdc@arm.com> Date: Fri, 3 Oct 2025 22:35:12 +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 mm-new 2/2] mm/khugepaged: merge PTE scanning logic into a new helper To: Lance Yang , akpm@linux-foundation.org, david@redhat.com, lorenzo.stoakes@oracle.com Cc: ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, baohua@kernel.org, ioworker0@gmail.com, richard.weiyang@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20251002073255.14867-1-lance.yang@linux.dev> <20251002073255.14867-3-lance.yang@linux.dev> Content-Language: en-US From: Dev Jain In-Reply-To: <20251002073255.14867-3-lance.yang@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 02/10/25 1:02 pm, Lance Yang wrote: > From: Lance Yang > > As David suggested, the PTE scanning logic in hpage_collapse_scan_pmd() > and __collapse_huge_page_isolate() was almost duplicated. > > This patch cleans things up by moving all the common PTE checking logic > into a new shared helper, thp_collapse_check_pte(). > > Suggested-by: David Hildenbrand > Signed-off-by: Lance Yang > --- > In hpage_collapse_scan_pmd(), we enter with mmap lock held, so for an anonymous vma, is it even possible to hit if (!folio_test_anon(folio))? In which case we can replace this with VM_BUG_ON_FOLIO and abstract away till the folio_maybe_mapped_shared() block?