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([2620:10d:c091:500::3:4e10]) by smtp.gmail.com with ESMTPSA id af79cd13be357-811b7490eaesm715891685a.65.2025.09.08.07.28.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Sep 2025 07:28:17 -0700 (PDT) Message-ID: Date: Mon, 8 Sep 2025 10:28:17 -0400 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 v2 1/1] mm: skip mlocked THPs that are underused early in deferred_split_scan() Content-Language: en-GB To: Lance Yang , akpm@linux-foundation.org, david@redhat.com Cc: Liam.Howlett@oracle.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, dev.jain@arm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, npache@redhat.com, ryan.roberts@arm.com, ziy@nvidia.com References: <20250908090741.61519-1-lance.yang@linux.dev> From: Usama Arif In-Reply-To: <20250908090741.61519-1-lance.yang@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 08/09/2025 10:07, Lance Yang wrote: > From: Lance Yang > > When we stumble over a fully-mapped mlocked THP in the deferred shrinker, > it does not make sense to try to detect whether it is underused, because > try_to_map_unused_to_zeropage(), called while splitting the folio, will not > actually replace any zeroed pages by the shared zeropage. > > Splitting the folio in that case does not make any sense, so let's not even > scan to check if the folio is underused. > > Suggested-by: David Hildenbrand > Signed-off-by: Lance Yang Acked-by: Usama Arif