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([2a02:6b6f:e750:1b00:1cfc:9209:4810:3ae5]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-46e2ab6a514sm120108055e9.22.2025.09.26.08.19.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 26 Sep 2025 08:19:42 -0700 (PDT) Message-ID: <37ec3e8b-e46d-40d4-826d-b4b2378015cb@gmail.com> Date: Fri, 26 Sep 2025 16:19:41 +0100 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 mm-new 05/12] mm: thp: decouple THP allocation between swap and page fault paths Content-Language: en-GB To: Yafang Shao , akpm@linux-foundation.org, david@redhat.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, hannes@cmpxchg.org, gutierrez.asier@huawei-partners.com, willy@infradead.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, ameryhung@gmail.com, rientjes@google.com, corbet@lwn.net, 21cnbao@gmail.com, shakeel.butt@linux.dev, tj@kernel.org, lance.yang@linux.dev Cc: bpf@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250926093343.1000-1-laoar.shao@gmail.com> <20250926093343.1000-6-laoar.shao@gmail.com> From: Usama Arif In-Reply-To: <20250926093343.1000-6-laoar.shao@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 26/09/2025 10:33, Yafang Shao wrote: > The new BPF capability enables finer-grained THP policy decisions by > introducing separate handling for swap faults versus normal page faults. > > As highlighted by Barry: > > We’ve observed that swapping in large folios can lead to more > swap thrashing for some workloads- e.g. kernel build. Consequently, > some workloads might prefer swapping in smaller folios than those > allocated by alloc_anon_folio(). > > While prtcl() could potentially be extended to leverage this new policy, > doing so would require modifications to the uAPI. > > Signed-off-by: Yafang Shao > Reviewed-by: Lorenzo Stoakes > Cc: Barry Song <21cnbao@gmail.com> > --- > include/linux/huge_mm.h | 3 ++- > mm/huge_memory.c | 2 +- > mm/memory.c | 2 +- > 3 files changed, 4 insertions(+), 3 deletions(-) > Acked-by: Usama Arif