From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f174.google.com (mail-qk1-f174.google.com [209.85.222.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AEAB39DBC6 for ; Thu, 26 Mar 2026 20:30:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774557051; cv=none; b=r4DQMufwPkiqT380OzhkB5TAbi2Yqzi4Oym/5YYFOJ4YDXlm1P/H9Jyx2Bz2yooRyetuJlGh6oM6oPsNhcdI7S33U1xvyhyH6qAGoO0j79JJ/JxwLqpgu48tEdUL1lB7fETll4L72IrOPgCLQUEE7tWjQUA/VJMb/QjzaRPKH6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774557051; c=relaxed/simple; bh=MFuStYaTciGnTN4F0M0soWQLcMi2bMJJDLwUQ3uHv68=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UQsQclhwOjl8qV+3I9c9wQb9HJ+8u736oXOnG7xx+rQZCEm5cNCpgPTOuNaeXR01vittwiruq3AYEOTybBRO9ugxBYPZvWlQv6mrI+sbiG2lYET6bqeIao8WuNxsUk/0u/0RkY+MDih99OsNO3sDLIJB5qI6qIJVZMaNndVT/A8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=qZbivxfQ; arc=none smtp.client-ip=209.85.222.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="qZbivxfQ" Received: by mail-qk1-f174.google.com with SMTP id af79cd13be357-8cd7ecedf2cso158269385a.3 for ; Thu, 26 Mar 2026 13:30:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1774557049; x=1775161849; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=gtpETcl3yk6gc9JzFTgqg++pyqjs/XxnbLkYQgCVFgc=; b=qZbivxfQ0kZ3LWINeIp6YXOjb0UO4V+Sx61Y6AV5ZpPIbVPIp1G0JjqaALutilNdCh cGyXmJPqswiUxXFT/KHy9pmnOT4MP0cxGvywoN+UsGLXqsADkabZl/7z1ibwaWogm/yF d6zndqU4tIOqGwji/zLv8EQYYhyvOSebu4DiE7HKGIvZApSR3XuIfpfepllDCP1WBl/l qn9KQTucpKNkfEt6CNJS3kohOamugheE2aKH+39r8mbCfr9Zv34Hvu1vGKMSkqBdU4oz iVjJav2MFNK5f22hrU+bF0hOwDmSK1VBPR2c34kRpn2ItE720zU7qlDx35pAaFsXnNRG gpug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774557049; x=1775161849; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=gtpETcl3yk6gc9JzFTgqg++pyqjs/XxnbLkYQgCVFgc=; b=pNELPIp5wbl0D7SadLd9Eok46zsqwOHEQeguI9KQDWiiFAyHMwt2DWPU5nxGwNDErU Og1xZhgP5xiZ2U8P86snr5GRetyYEsE7j8LpJoqjSIQ+biTqRZXur83ghvGjVc/ROsF6 YTfKJbz3Wy0aWMh4CmBTlHNhwzRFB8D+PWGCD7Ru9R+HiLIVl2bDU9jiZxH++4wtbpTq 9z/uQANlkFPcS6PrLC/BLE55ZqMuPlBX71nNu65ThrzAzHJ2EM2FN0J68yI0CdBGRx/k s04IBraI2+ZMCsa5JLzbbmP7W2t2Bbh5PwFY8y43vD0fhwgKj4Ac4O+5/oeHoc5losd3 kFyQ== X-Forwarded-Encrypted: i=1; AJvYcCWtYQPF3rR7C3tangu0onJ5L6ZmjIjwRZgZipVu5wSRQaT1kaotEwHWaRdi0qww1d3AaAI=@vger.kernel.org X-Gm-Message-State: AOJu0Yw+BgYhNIlfJxV7EjA+NCeZ87KNayGN4FrUCjZdkh+OygaZLWAi ht55pSJrS3p/V3dGD7Wup7T9Vmgpd65x0uhxlr6s+WLhh2Q3vZnkVo8iZLStOvysMS8= X-Gm-Gg: ATEYQzysAa12LTqCZKWys67+KTxM2ht9K5omAFWNgot6x/CNQri2TZ8T5Kukb0eht1x Q+MTm5SLD854DQ6smMfoppFfq3UK4mSme/A9mMpiZ4Vqis9d9Y6SANB4KjLRP1ZksuoFDNmeYno oF/ck5Vkzdrq+I1OueMegicY/nx40MubgAmZ/x7K6U7GPU9wMllkcs+6ZZEFnP2dg+ErTSg5oOD Ehlz5VZn2DA/7OtIZL+9vsnHh3qEnDraBWnEYcCv07S8mCpqhgdL9ocdvCMv4g9wHl5vj+phTOs FOsdgWkLgaXEr047fAfjp/1ei8wNm/8gOcJBBUFDDHA5I/anDta42R/8UGFkX6n6s5W4TA1Ss39 NsL8ezgjaswRpfBPbUGHVzE+yVbhxLuVMS3uSVTP+Thtl54yJwRVgD8ZbE4elqaYpDozRw7c5O7 nOia+xtyYMPzCYqwqAKafL X-Received: by 2002:a05:620a:198c:b0:8cf:d804:4567 with SMTP id af79cd13be357-8d000f20fcfmr1253345285a.23.1774557049133; Thu, 26 Mar 2026 13:30:49 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F ([2620:10d:c091:500::2:e5e8]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8d00e4ca250sm323370585a.25.2026.03.26.13.30.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Mar 2026 13:30:48 -0700 (PDT) Date: Thu, 26 Mar 2026 15:30:46 -0500 From: Gregory Price To: Axel Rasmussen Cc: "Lorenzo Stoakes (Oracle)" , Michal Hocko , Andrew Morton , Shakeel Butt , lsf-pc@lists.linux-foundation.org, Johannes Weiner , David Hildenbrand , Qi Zheng , Chen Ridong , Emil Tsalapatis , Alexei Starovoitov , Yuanchu Xie , Wei Xu , Kairui Song , Matthew Wilcox , Nhat Pham , Barry Song <21cnbao@gmail.com>, David Stevens , Vernon Yang , David Rientjes , Kalesh Singh , wangzicheng , "T . J . Mercier" , Baolin Wang , Suren Baghdasaryan , Meta kernel team , bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [LSF/MM/BPF TOPIC] Towards Unified and Extensible Memory Reclaim (reclaim_ext) Message-ID: References: <20260325210637.3704220-1-shakeel.butt@linux.dev> <20260325190547.abb7309fb63473b57b7a90a0@linux-foundation.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Mar 26, 2026 at 01:02:02PM -0700, Axel Rasmussen wrote: > > I think one thing we all agree on at least is, long term, there isn't > really a good argument for having > 1 LRU implementation. E.g., we > don't believe there are just irreconcilable differences, where one > impl is better for some workloads, and another is better for others, > and there is no way the two can be converged. > I absolutely believe there are irreconcilable differences - but not in the sense that one is better or worse, but in the sense that features from one cannot work in the other. > - My sense is MGLRU is "close", meaning as Kairui said in "average" > cases it is substantially better, and the gaps are both fairly narrow > / edge-casey, and very solveable. > This is a really, really bold claim. So much of this is workload dependent, and LRU has decades of battle-testing while MGLRU has barely been around 4 years. ~Gregory