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Received: from 30.74.144.116(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XAFfT1p_1788430262 cluster:ay36) by smtp.aliyun-inc.com; Thu, 03 Sep 2026 18:11:03 +0800 Message-ID: <0f2d9837-0198-46f6-8988-8bc089c1234b@linux.alibaba.com> Date: Thu, 3 Sep 2026 18:11:00 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/7] mm/mglru: enhance cold/hot inversion handling in inc_min_seq() To: "Barry Song (Xiaomi)" , akpm@linux-foundation.org, linux-mm@kvack.org Cc: axelrasmussen@google.com, baoquan.he@linux.dev, chenridong@xiaomi.com, david@kernel.org, hannes@cmpxchg.org, kasong@tencent.com, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, ljs@kernel.org, lyugaofei@xiaomi.com, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, stevensd@chromium.org, wangzicheng@honor.com, weixugc@google.com, yuanchu@google.com, zhangbo56@xiaomi.com, Xueyuan Chen , Ridong Chen References: <20260901232421.40157-1-baohua@kernel.org> <20260901232421.40157-4-baohua@kernel.org> From: Baolin Wang In-Reply-To: <20260901232421.40157-4-baohua@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: E387740002 X-Stat-Signature: 4ygz5uoiccr1nu1yfku36of571qo3myq X-HE-Tag: 1788430268-364406 X-HE-Meta: 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 UTTbgvzj 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/2/26 7:24 AM, Barry Song (Xiaomi) wrote: > During aging, a folio's generation may already have been updated by > folio_update_gen(), even though it has not yet been moved to the > corresponding generation list. Such folios are hotter than those > already in that generation. > > It makes sense for inc_min_seq() to increment the generation of > folios that were never promoted during aging and move them to the > tail of the new oldest generation. However, folios that were already > promoted should instead be moved to the head of their updated > generation, just as sort_folio() does in scan_folios(). > > Otherwise, promoted folios could end up behind folios that were > never promoted, effectively inverting their hot/cold ordering. > > Signed-off-by: Barry Song (Xiaomi) > Reviewed-by: Kairui Song > Tested-by: Xueyuan Chen > Reviewed-by: Ridong Chen > Reviewed-by: Lian Wang > --- Good catch. Make sense to me. Reviewed-by: Baolin Wang